- Email: [email protected]
GSM applications
Journal Pre-proofs A Miniaturized Quad-band Antenna with Slotted Patch for WiMAX/WLAN/ GSM Applications Ajay Kumar Gangwar, Muhmmad Shah Alam PII: DOI: Reference:
S1434-8411(19)30978-1 https://doi.org/10.1016/j.aeue.2019.152911 AEUE 152911
To appear in:
International Journal of Electronics and Communications
Received Date: Accepted Date:
13 April 2019 5 September 2019
Please cite this article as: A. Kumar Gangwar, M. Shah Alam, A Miniaturized Quad-band Antenna with Slotted Patch for WiMAX/WLAN/GSM Applications, International Journal of Electronics and Communications (2019), doi: https://doi.org/10.1016/j.aeue.2019.152911
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A Miniaturized Quad-band Antenna with Slotted Patch for WiMAX/WLAN/GSM Applications
Article reference: AEUE_2019_938 Article title: A Miniaturized Quad-band Antenna with Slotted Patch for WiMAX/WLAN/GSM Applications
Names and their Affiliations Corresponding and first Author: Name: Ajay Kumar Gangwar Affilication: HMR Institute of Technology and Management, New Delhi ( Guru Gobind Singh Indraprastha University, New Delhi, India)
Second Author: Name: Muhmmad Shah Alam Affilication: Zakir Husain College of Engineering and Technology, Aligarh (UP) ( Aligarh Muslim University, Aligarh, India)
Complete contact information Ajay Kumar Gangwar Department of Electronics and Communication Engineering HMR Institute of Technology and Management, Plot No. 326, Bakoli HMRITM Rd, Hamidpur, New Delhi, Delhi, India 110036. Email id: [email protected]
Corresponding Author Name and E-Mail ID Corresponding author Name: Ajay Kumar Gangwar Email id: [email protected]
Biography Ajay Kumar Gangwar received his B.Tech degree in Electronics and Communication Engineering and M.Tech degree in Digital Communication Engineering from Uttar Pradesh Technical University, Lucknow, India in 2009 and 2012 respectively. During the master degree, he was awarded MHRD gate fellowship. From 2012 to 2014, he was worked as an Assistant Professor at Institute of Engineering and Technology, Alwar (Rajasthan), India. He completed his Ph.D. degree in 2018 from Aligarh Muslim University, Aligarh, India. During the Ph.D. degree, he was awarded UGC fellowship. Now at the time, he is working as an assistant professor in the department of electronics and communication engineering at HMR institute of technology and management, New Delhi, India. He served research in the area of multiband antennas, filters, power divider and different metamaterial structures. He published more than seventeen papers in the reputed journals and conferences. He is also member of several technical societies such as the institute of Engineers (IE) India, Photonic society of India and Indian society for technical education (ISTE), India.
Muhmmad Shah Alam obtained his B.Sc. Engineering (Electronics & Communication Engineering) and M.Sc. Engineering (Electronics & Communication Engineering) degrees from Aligarh Muslim University (AMU), Aligarh in the year 1988 and 1991, respectively. He was awarded Queen's research fellowship, which is quite rare to obtain for non-European students, for carrying out research at the Queen's University of Belfast (UK) from where he obtained his PhD degree in Electronics Engineering in the year 2002. In the year 2010, he completed his post-doctoral study from the QUB, UK in the area of Nano-electronics under Commonwealth Fellowship Programme. In 1993, he joined the Department of Electronics Engineering, AMU, Aligarh, as a Lecturer, and in 1998 became a Sr. Lecturer. Since 2002, he served the department as a Reader and became an Associate Professor in 2006, and subsequently a Professor in 2009. His current research interests include •Millimeter Wave Circuits and their Battery-less ("Green") Operation for Internet-of-Everything (IoE) •Multi-band rf Circuit Design for Wireless Gigabit
Wireless Communication •Evaluation and Performance Comparison of Emerging Device Technologies •RF Models for GHz Circuits •Nanocomposite Materials for Supercapacitor and Antenna Applications. Dr. Alam is a Fellow of the Institution of Electronics and Telecommunication Engineers (IETE) (India). He is Senior Member of Institution of Electrical and Electronics Engineers (IEEE) (USA); Life Member of Indian Society for Technical Education (ISTE) and System Society of India. He has been a visiting scientist to: The Technical University Dresden, Germany from 20 November-19 December, 2014 under DFG-INSA Bilateral Exchange Programme; the University of Ottawa, Canada during 23-24 October 2010; Nano-technology Centre, QUB (UK) from December 2004 to February 2005 jointly Funded by the Royal Society of London (UK) & DST (Govt. of India) for encouraging collaborative research work between Excellent Young and Outstanding Scientists of UK and India. He collaborated with the Parthus Technologies Limited, Belfast (UK) and High Frequency Research Group at the QUB and the project entitled, ‘RF Modeling of Sub-micron CMOS for Radio Frequency Circuit Design’ in year 2002. Dr. Alam has successfully completed a major research project (₹23, 814, 00) in 2010 Funded by the Department of Science and Technology (DST), Govt. of India under National Mission on Nano Science and Technology. Dr. Alam collaborated with the QUB and completed the project entitled, ‘Design of Novel Nano-scale Devices for Low Power Application’ in year 2014. He was an Indian PI for the collaborative project entitled, ‘Performance Comparison of state-of-art CMOS and SiGe LNA for Multi-band Wireless’, with German PI: Prof. Dr.-Ing. Michael Schroeter, Chair for Electron Devices and Integrated Circuits, Technical University Dresden, Germany and successfully completed the project in year 2014, funded by INSA, Govt. of India, & DFG, Govt. of Germany. He has been to several countries including UK, USA, Canada, Denmark, France, Turkey and Singapore for the purpose of academic interaction or collaborative research. He has signed NDA for technology support from IHP Germany during 2019-2021 to carry out RF/Millimeter-Wave Circuit Design up to 300 GHz. He Chaired a Technical Session in 18th IEEE MTT-S Mediterranean Microwave Symposium (MMS-2018), Istanbul, Turkey, from 31 October-02 November 2018. He is a reviewer of number of reputed international journals including IEEE and IET. He has worked extensively in the areas of Millimeter Wave Circuit, RF device modeling and nano-electronics and published more than 60 research papers including reputed International journals like Microwave Optical Letter, International Journal of Electronics, and Solid-state Electronics. Dr. Alam has an interest in the teaching of courses like RF Circuits & Systems, Digital Electronics, Circuit Theory, Advanced Device Modeling, RF System Design, µWave Devices & ICs, µWave and Antenna and µWave Engineering.
Abstract- A miniaturized quad-band patch antenna for WiMAX/WLAN/GSM applications is presented in this paper. The proposed antenna structure consists two L-slots and a slit in the patch. The longer between two slots, resonates at 1.74 GHz (1.8 GHz band), whereas the shorter at 2.58 GHz (2.4/2.5 GHz band). The third and fourth resonances at 3.6 GHz (3.5 GHz band) and 5.6 GHz (5.2/5.5/5.8 bands) are due to the slit and length of the patch, respectively. A detail parametric analysis is carried out by varying the length of the slots (i.e. L-slots and slit) to achieve the desired frequency bands. An equivalent circuit model of the antenna is developed and the various antenna performances are analyzed. The antenna simulated results for return loss and 2D radiation patterns are experimentally verified.
1.
INTRODUCTION
There is a great demand to integrate various communication standards like GSM, WLAN and WiMAX applications into a single mobile unit [1].
The specified spectrum for WiMAX (IEEE 802.16) is 2.5 GHz
(2.5–2.69 GHz), 3.5/5.5 GHz (3.4–3.69, 5.25– 5.85 GHz), WLAN (IEEE 802.11) 2.4 GHz (2.4–2.484 GHz), 5.2/ 5.8 GHz (5.15–5.35, 5.725–5.825) and for 1.8 GHz GSM band is (1.710-1.880 GHz) [2] [11]. To fulfill these requirements number of multiband antennas are studied [2] [3]-[12]. They utilize several techniques such as metamaterials, meandering lines, cutting slots and fractal shapes to make their design compact. In [3]-[5], metamaterial multiband antennas were designed using hexagonal-shaped split ring radiating structure [3], etching of inverted L-slot in the monopole with additional reactive load [4], cutting a T-slot in the patch with meandered lines [5] open strip ring resonator as a radiating element [6] and tapered shaped radiating element and a meta-atom (complementary split ring resonator-CSRR) loaded in the ground plane [7]. Similarly, in [8], a triple band monopole antenna was realized by a tooth brush-shaped patch, a meander line, and an inverted U-shaped patch for WLAN and WiMAX applications. For the same applications, antennas were developed using fork shaped strip with a modified rectangular ring [9] and by loading a complementary right/left-handed unit cell [10]. The multiband antennas developed in [3]-[10] covers all the bands of WLAN and WiMAX but they are complex in design (thus higher cost). In [11], SRR-based polygon rings penta-band fractal antenna is used, which covers either single or dual bands of WLAN, WiMAX and GSM. Similarly, a compact size multiband antenna using asymmetric coplanar strip (ACS) feed has been developed for WLAN/WiMAX/ Bluetooth/ LTE but covers a single band for these applications [12]. The designs developed in [11] [12] are complex and all the bands of WLAN/WiMAX are not covered. Although, they do cover single band of GSM/ Bluetooth/ LTE [11] [12]. Therefore, in this paper, proposes to develop a more compact size (as compared to the earlier work [3]-[12] multiband antenna, which not only covers all the bands of WLAN/WiMAX but GSM band as well. The proposed antenna consists of a rectangular patch with two L-slots and a slit to generate four resonances, which are resonated at 1.74 GHz, 2.58 GHz, 3.61 GHz and 5.60 GHz covered all the bands of WiMAX/WLAN and 1.8 GHz GSM band. An equivalent circuit model of the antenna is developed for understanding the resonance and coupling behaviors. In the model, each resonance is represented by a tank circuit (parallel R LC) and mutual inductive coupling by LM. Using the technique described in [13]-[15], the model components value are theoretically estimated and further optimized in Keysight ADS [16] for reflection coefficient S11<-10dB. An input impedance (ZIN) expression by accounting asymptotic behavior at lower and higher frequencies is derived [17]. Furthermore, the power loss due impedance mismatch at each resonance frequency is determined. 2.
PROPOSED ANTENNA DESIGN
The proposed monopole multiband antenna has been designed on FR4 substrate with dielectric constant 4.4, loss tangent 0.02 and height of 1.6 mm. The antenna consists of partial ground plane with two L-slots and a slit in the patch as illustrate in Figure 1. The geometries of the antenna are optimized for the desired bandwidth with acceptable S11≤-10dB. The optimized size of the antenna is resonated at 1.74 GHz, 2.58 GHz, 3.6 GHz and 5.58 GHz, which are mainly due to the two L-slots, slit and patch, respectively. The antenna optimized geometries are given in Table I. The design flow of the proposed antenna is described in the flowchart given in Figure 2, which essentially involved four design steps. In the first step, a single band monopole antenna is designed, which resonates at 5.26 GHz as shown in Figure 3 (a). In the second step, dual band operation is achieved by cutting L-slot in the patch on the left side of the feed line, which is responsible for resonance at 2.58 GHz and 5.36 GHz as illustrated in Figure 3 (b). Similarly, in the third step, tri-band operation is achieved by cutting another L-slot to the right side of the slot in the previous design i.e. second step and three resonances at 1.74 GHz, 2.58 GHz and 5.36 GHz are achieved (See Figure 3 (c)). In the fourth step, an additional slit is introduced in the patch at the right side of the feedline and the final structure (i.e. patch with two L-slots and a slit) resonates at 1.74 GHz, 2.58 GHz, 3.6 GHz and 5.58 GHz as shown in Figure 3 (d). Thus, the proposed antenna has designed by the fourth step process. In the antenna, the length of the two L-slots as shown in Figure 3(d) (i.e. L12=13.60 mm, L34=19.90 mm) and slit (i.e. L5=10.82 mm) were found approximately equal to quarter guided wave length ( g/4) at 2.58 GHz, 1.74 GHz and 3.6 GHz, respectively. The proposed antenna has no ground plane underneath the radiating patch (with two narrow slots), therefore, the radiation patterns are bidirectional [18]. The occurrence of resonances in the proposed antenna are further examined with the help of surface current distribution [19] as shown in Figure 4(a)-4(c). In Figure 4(a), the higher current at1.74 GHz is mainly confined in the longer L-slot, which justify its role for the occurrence of resonance at this frequency. Similarly, as shown in Figure 4(b) and 4(c), shorter L-slot and slit are responsible for exitance of resonance at 2.58 GHz and 3.60 GHz, respectively. 3.
PARAMETERIC ANALYSIS
It has been observed in Section 2.0 that the first three resonance frequencies (1.74 GHz, 2.58 GHz and 3.60 GHz) are due the length of the slots/slit (namely L34, L12 and L5). The L34, L12 and L5 where found approximately equal to λg/4, where λg is the guided wavelength [20] as shown in Figure 3. By using guided wavelength λg/4 at 1.74 GHz, 2.58 GHz and 3.60 GHz were determines as 20.90mm,13.60mm 10.82mm, respectively. Now, their values are marginally perturbed to see their effect on each resonance frequency. As shown in Figure 5(a), when L34 is increased from 18.90 mm to 20.90 mm, then the first resonance frequency is decreased from 1.91GHz to 1.74 GHz, whereas the other resonances remain unaffected. With an optimum value L34 =19.90 mm, the first resonance observed at 1.74 GHz, which covers the 1.8 GHz GSM band. Similarly, as L12 is increased from 12.60 mm to 14.60 mm, then the second resonance frequency is decreased from 2.75GHz to 2.47 GHz, whereas the other resonances remain unaffected as shown in Figure 5 (b). With the optimum length L12=13.6 mm, the resonance occurred at 2.58 GHz, which covers 2.4/2.5 GHz bands. Furthermore, as L5 is
increased from 9.82 mm to 11.82 mm, then the third resonance frequency is decreased from 3.79 GHz to 3.26 GHz, whereas other resonances remain unaltered as shown in Figure 5 (c). With an optimum L5 =10.82 mm, the third resonance at 3.58 GHz covers 3.5 GHz band. As far as fourth resonance (5.64 GHz) is concerned, it remains unaffected by changes in L12, L34 and L5 and it covers 5.2/5.5 GHz and 5.8 GHz bands. Since the ground plane length Lg and width Wg affects the antenna performance, therefore a detail parametric studies by varying Lg and Wg have been carried out as shown in Figure 6 (a)-(b). By observing Figure 6(a), it can be concluded that by changing Lg has no effect on 1st and 2nd resonances, whereas higher resonances (i.e. 3rd & 4th) are affected. Similarly, by varying has no effects on all other resonances (i.e. 1st, 2nd & 3rd) except the minor change in 4th resonance is observed.
4.
EQUIVALENT CIRCUIT MODEL
To investigate the resonance behavior of the antenna, an equivalent circuit model is developed. By using the Foster’s representation, the lossless input impedance ZIN of the antenna can be expressed as [13]: jω
3
ZIN = ∑n = 0C
(
)
2 n ω2 n―ω
1 st term
+ jωLM12 + jωLM23 + 2nd term
3rd term
1 jωCs 4th term
+ jωLs
(1)
5th term
In Eq. (1), 1st term indicates the four resonances modelled as parallel LC tank circuits, whereas 2nd and 3rd terms i.e. LM12 and LM23 model the inductive coupling effect between the slots (L12 and L34 ) and (L34 and L5), respectively. The 4th term accounts for capacitive impedance 1/(jCS) for the asymptotic behavior of ZIN at low frequency, whereas 5th term represents the inductive impedance jLS to counter balance the 4th term effect at the high frequency. However, when losses are incorporated for each tank circuit and modelled as R0, R1, R2 and R3, respectively, then modified equivalent circuit obtained as illustrated in Figure 7. By accounting these resistances, the first tank circuit modelled (R0, L0 and C0) and its associated impedance Z0 can be expressed as:
Zo = (R
jωR0L0 0
(2)
― ω2R0L0C0) + jωL0
Similarly, 2nd, 3rd and 4th tank circuits are modelled as R1L1C1, R2L2C2 and R3L3C3 and their respective impedances as Z1, Z2 and Z3, respectively. By including the losses, the modified ZIN can be expressed as: 1
ZIN = Z0 + Z1 + Z2 +jωLM12 +jωLM34 + jωCs +jωLs
(3)
Using, Eq. (1)-(3), various components are theoretically determined as discussed in [12]-[14]. Thereafter, their values are optimized using Keysight ADS [16] for reflection coefficient S11<-10dB as shown in Figure 8. The optimized circuit components values are summarized in Table II. 5.
INPUT IMPEDANCE MISMATCH LOSS (IML)
The input power loss due impedance mismatch is quantified in terms of IML [18]-[19], which is expressed as: IML (dB) = 10log (1 ― |S11|2)
ZIN ― Z0
Where S11 = ZIN ― Z0
(4)
The power loss in the antenna design associated with impedance mismatch can be reduced by adjusting characteristic impedance ZO of the feed line close to ZIN. Since ZO strongly depends on the width of the feedline, which can be optimized to achieve the impedance match. The IML has been calculated at each resonance frequency and its values are given in Table III. 6.
RESULTS AND DISCUSSION
The prototype of the proposed antenna is developed and simulated results (return loss & 2D radiation patterns) are experimentally verified. As shown in Figure 9, that the measured frequency range are (taken at S11@-10dB): (1.64-1.89 GHz), (2.39-2.70GHz), (3.4-3.7GHz) and (5.15-6.19GHz), which cover 1.8GHz band of GSM and all the bands of WLAN and WiMAX. The simulated and measured 2D radiation patterns at different resonance frequencies (i.e. 1.74 GHz, 2.58 GHz, 3.6 GHz and 5.58 GHz) are shown in Figure 10. It can be observed from Figure 10 that the simulated and measured radiation patterns slightly differ at these frequencies, which are mainly due to fabrication & measurement errors. As shown in Figure 11, the proposed antenna achieved the gain (efficiency) as: 1.70 dBi (94.30%), 1.8dBi (94.25%), 2.61 dBi (90.44%) and 2.86 dBi (92.83%) at 1.74 GHz, 2.58 GHz, 3.6 GHz and 5.58 GHz, respectively. The performance comparison of the proposed antenna with the reported works in literature in terms of size, frequency bands, gain and bandwidth are summarized in Table IV. As observed from the Table IV that the proposed antenna in this work is compact in size, which can be profitably utilized in the form of array for wireless power transmission application [21].
7.
CONCLUSIONS
In this paper a compact size multiband antenna has been designed for WiMAX, WLAN and GSM applications. The multiband operation of the antenna is achieved by cutting two L-slots with a slit in the radiating patch. The simulation results for return loss and radiation patterns are experimentally verified. An equivalent circuit model is developed to analytically analyze the antenna performance. The antenna proposed in this work demonstrates bidirectional and omnidirectional radiation patterns at E and H plane, respectively. Since the proposed antenna is compact in size with omnidirectional radiation pattern, which justify its suitability for wireless communication system. 8.
ACKNOWLEDGEMENTS
The authors appreciate the financial support received under TEQIP-III for the expenditure incurred by using Antenna Measurement Lab Facility at the Indian Institute of Technology (IIT), Kanpur, India.
REFERENCES 1. Ketavath Kumar Naik, Asymmetric CPW-fed SRR patch antenna for WLAN/WiMAX applications, International journal of electronics and communications (AEÜ), 2018, 93, 103-108. 2. Yan Zhang and Nirwan Ansari, Wireless telemedicine services over integrated IEEE 802.11/WLAN and IEEE 802.16/WiMAX networks, IEEE wireless communications, 2010, 30-36. 3. S. Imaculate Rosaline and S. Raghavan, Metamaterial inspired monopole antenna for WLAN/WiMAX applications, Microwave and optical technology letters, 2016, 58, 936-939. 4. H. Huang, Ying Liu, Shaoshuai Zhang and Shuxi Gong, Multiband metamaterial-loaded monopole antenna for WLAN/WiMAX Applications, IEEE antennas and wireless propagation letters, 2015,14, 662-665. 5. Pratyush Pushkar and Vibha Rani Gupta, a metamaterial-based tri-band antenna for WIMAX /WLAN application, Microwave and optical technology letters, 2016, 58, 558-561. 6. Rengasamy Rajkumar and Kommuri Usha Kira, A metamaterial inspired compact open split ring resonator antenna for multiband operation, Wireless personal communications, 2017, 97, 951–965. 7. Rajeshkumar Venkatesan, Rajkumar Rengasamy, Praveen Vummadisetty Naidu and Arvind Kumar, A compact meta-atom loaded asymmetric coplanar strip-fed monopole antenna for multiband operation, International journal of electronics and communications, 2019, 98, 241-247. 8. Yingsong Li andWenhua Yu, a miniaturized triple band monopole antenna for WLAN and WiMAX Applications, Hindawi publishing corporation international journal of antennas and propagation, 2015, 1-5. 9. Li Li, Xiaoliang Zhang, Xiaoli Yin and Le Zhou, a compact triple-band printed monopole antenna for WLAN/WiMAX applications, IEEE antennas and wireless propagation letters, 2016, 15, 1853-1855. 10. Sourav Nandi and Akhilesh Mohan, CRLH unit cell loaded triple band compact monopole antenna for WLAN/WiMAX applications, Microwave and optical technology letters 2017, 59, 686-691. 11. V. Rajeshkumar and Singaravelu Raghavan, SRR-based polygon rings penta-band fractal antenna for GSM/WLAN/WIMAX/ ITU band applications, Microwave and optical technology letters, 2015, 57, 1301-1305. 12. Praveen V. Naidu, Printed V-shape ACS-fed compact dual band antenna for bluetooth, LTE and WLAN/WiMAX applications. Microsystem technologies, 2016, 23, 1005–1015. 13. Michael Hamid and Rumsey Hamid, Equivalent circuit of dipole antenna of arbitrary length, IEEE Transactions and Propagation, 1997, 45, 1695-1696. 14. F. Gronwald, S. Gluge, and J. Nitsch, On network representations of antennas inside resonating environments, Advances in radio science, 2007, 5, 157-162. 15. A.K. Gangwar and M. S. Alam, A SSRR based multiband antenna for mobile phone, 2016 Twenty second national conference on communication (NCC), IIT Guwahati, 2016, 1-4. 16. Keysight Advanced Design System (ADS) 2019; www.keysight.com 17. A. K. Gangwar and MS Alam, CSRR based folded monopole tri-band antenna array and its system level evaluation, International journal of RF and microwave computer aided engineering 2018, 1-9. 18. Robert E. Collin, Antennas and radio wave propagation, McGraw-Hill, 1985, 6. 19. Thomas A. Milligan, Modern antenna design john wiley & Sons, 2005, 17-18. 20. A. K. Gangwar and MS Alam, A high FoM monopole antenna with asymmetrical L-slots for WiMAX and WLAN applications, Microwave and optical technology letters, 2017, 60, 196–202. 21. A. F. Morabito, Synthesis of maximum-efficiency beam arrays via convex programming and compressive sensing, IEEE Antennas and wireless propagation letters, 2017, 16, 2404-2407.
(a)
(b)
Figure 1. Geometry of the proposed antenna (a) top view (b) bottom view (c) side view.
(c)
Start
Determine the antenna dimensions using the given specifications Simulation using Keysight ADS
A monopole patch antenna is designed for single band (StepI)
For dual band operation, L-slot is cut in the patch of the monopole antenna from left side of the feed line (Step-II).
To operate the previous design (realized in Step-II) for triband operation, another L-slot is cut on the right side of the feed line (Step-III)
Optimum Results
For quad-band operation, an additional slit is introduced in the design obtained in Step-III, to the right side of the feed line (Step-IV)
No
Yes Fabrication process begins after the simulations results are optimized Return loss and radiation pattern measurement Comparison of simulated measurement results
and
End
Figure 2. Flow chart of the proposed multiband antenna design containing all the four basic steps involved.
(d) (c)
Returnloss (dB)
(a) (b)
(a)
(b)
(c)
(d)
Frequency (GHz) Figure 3. Simulated S11 for (a) monopole patch antenna (b) antenna with L12 slot (c) antenna with L12 and L34 slots (d) proposed antenna i.e. antenna with L12 and L34 slots and slit L5.
(a)
(b)
(c)
Figure 4. Surface current distribution of the proposed antenna at (a) 1.747 GHz (b) 2.58 GHz (c) 3.61 GHz.
0
(c)
Returnloss (dB)
-5 -10 -15 -20
L5=9.82 mm
-25
L5=10.82 mm -30
L5=11.82 mm
-35 0.5
1.5
2.5
3.5
Frequency (GHz)
4.5
5.5
6.5
Figure 5. Simulated S11 of the antenna by tuning the different value of (a) L34 (b) L12 (c) L5.
0
(a)
-5
S11 (dB)
-10 -15 -20 -25 Lg=7.88 mm Lg=8.38 mm Lg=8.88 mm
-30 -35 -40 0.0
1.0
2.0
3.0 4.0 Frequency (GHz)
5.0
6.0
0
(b)
-5 -10
S11 (dB)
-15 -20 -25 -30 -35 Wg=15.9 mm Wg=16.4 mm Wg=16.9 mm
-40 -45 -50 0.0
1.0
2.0
3.0 4.0 Frequency (GHz)
Figure 6. Simulated S11 of the antenna by tuning the different value of (a) Lg (b) Wg
Figure 7. Equivalent circuit model of the antenna
5.0
6.0
0
Returnloss (dB)
-5 -10 -15 -20 -25 Equivalent circuit
-30
Proposed Antenna
-35 0.5
1.5
2.5
3.5
4.5
5.5
Frequency (GHz)
Figure 8. Simulated S11 of the antenna and its equivalent circuit model.
Figure 9. Simulated and measured S11 of the antenna.
6.5
(a)
(b)
(c)
(d)
4.5
96
4
94
Returnloss (dB)
3.5
92
3
90
2.5
88
2
86
1.5 1 0.5
Gain
84
Efficiency
82
0
80 0.5
1.5
2.5
3.5
4.5
5.5
Frequency (GHz) Figure 11. Simulated gain and efficiency of antenna.
6.5
Efficiency (%)
Figure 10. Simulated and Measured (left) E-plane and (right) H-plane radiation pattern of the antenna (a) 1.74 GHz (b) 2.58 GHz (c) 3.61 GHz (d) 5.6 GHz
TABLE-I Dimensions of the antenna
Parameters Values (mm)
WF 2.20
Lf 11.30
WP 16.0
LP 12.70
L1 4.87
L2 9.13
L3 9.91
L4 11.07
L5 10.82
g 0.20
Wg 16.4
Lg 8.38
TABLE-II Optimized parameters of the equivalent circuit model
Parameters Values Parameters Values
R0 (Ω) 158.39 C2 (pF) 2.79
L0 (nH) 1.28 R3 (Ω) 35.07
C0 (pF) 0.94 L3 (nH) 1.62
R1 (Ω) 203.30 C3 (pF) 7.08
L1(nH) 2.35 LS (nH) 0.94
C1 (pF) 2.13 CS (pF) 0.92
R2(Ω) 229.08 LM1(nH) 0.82
TABLE-III Comparison of measured and simulated IML with ZO=50Ω
Measured
Simulated
Frequency (GHz)
S11 (dB)
IML(dB)
1.76 2.56 3.56 5.88 1.75 2.60 3.62 5.65
21.7 28.3 24.4 15.2 19.9 18.1 25.4 13.9
0.029 0.006 0.016 0.133 0.045 0.068 0.013 0.181
L2(nH) 0.93 LM2(nH) 1.91
TABLE-IV Comparison of performances between the proposed antenna and reported work in literature Ref.
L×W×h (mm3 ) (Year)
[2]
24×22.5×0.8 (2016)
[3]
45×40×1.0 (2015)
[4]
35×35×1.0 (2015)
[5]
27.5×16.08×1.6 ( 2017)
[6]
25×12.2×1.6 ( 2019)
[7]
30×20×0.8 (2015)
[8]
34×18×1.6 (2016)
[9]
20×21×1.57 (2017)
[10]
24×18×1.6 (2015)
Proposed Antenna
24×16.4×1.6
Frequency (GHz) 2.45 3.5 5.2 5.8 2.44 3.5 5.5 2.6 3.5 5.5 2.41 4.10 5.38 2.4 5.2 5.8 7.4 2.4 3.5 5.5 2.5 3.5 5.5 2.51 3.55 5.73 1.9 2.6 3.5 5.2 1.74 2.58 3.61 5.60
Gain (dBi)
B.W (MHz)
2.50 2.14 3.30 3.50 3.20 2.38 2.34 1.65 2.59 3.94 0.37 1.61 1.88 4.98 1.06 0.88 2.17 1.30 2.20 3.00 0.28 1.42 4.76 1.29 2.44 3.26 0.25 3.8 4.3 1.13 1.70 1.80 2.61 2.86
130 330 1540 1700 1600 280 760 700 80 200 2800 1100 2240 660 140 310 840 300 300 1000 210 300 1390 150 500 700 5050 220 320 330 810
Declaration of interests
☐ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
☐The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:
Ajay Kumar
Corresponding Author (Ajay Kumar Gangwar)
S1434-8411(19)30978-1 https://doi.org/10.1016/j.aeue.2019.152911 AEUE 152911
To appear in:
International Journal of Electronics and Communications
Received Date: Accepted Date:
13 April 2019 5 September 2019
Please cite this article as: A. Kumar Gangwar, M. Shah Alam, A Miniaturized Quad-band Antenna with Slotted Patch for WiMAX/WLAN/GSM Applications, International Journal of Electronics and Communications (2019), doi: https://doi.org/10.1016/j.aeue.2019.152911
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A Miniaturized Quad-band Antenna with Slotted Patch for WiMAX/WLAN/GSM Applications
Article reference: AEUE_2019_938 Article title: A Miniaturized Quad-band Antenna with Slotted Patch for WiMAX/WLAN/GSM Applications
Names and their Affiliations Corresponding and first Author: Name: Ajay Kumar Gangwar Affilication: HMR Institute of Technology and Management, New Delhi ( Guru Gobind Singh Indraprastha University, New Delhi, India)
Second Author: Name: Muhmmad Shah Alam Affilication: Zakir Husain College of Engineering and Technology, Aligarh (UP) ( Aligarh Muslim University, Aligarh, India)
Complete contact information Ajay Kumar Gangwar Department of Electronics and Communication Engineering HMR Institute of Technology and Management, Plot No. 326, Bakoli HMRITM Rd, Hamidpur, New Delhi, Delhi, India 110036. Email id: [email protected]
Corresponding Author Name and E-Mail ID Corresponding author Name: Ajay Kumar Gangwar Email id: [email protected]
Biography Ajay Kumar Gangwar received his B.Tech degree in Electronics and Communication Engineering and M.Tech degree in Digital Communication Engineering from Uttar Pradesh Technical University, Lucknow, India in 2009 and 2012 respectively. During the master degree, he was awarded MHRD gate fellowship. From 2012 to 2014, he was worked as an Assistant Professor at Institute of Engineering and Technology, Alwar (Rajasthan), India. He completed his Ph.D. degree in 2018 from Aligarh Muslim University, Aligarh, India. During the Ph.D. degree, he was awarded UGC fellowship. Now at the time, he is working as an assistant professor in the department of electronics and communication engineering at HMR institute of technology and management, New Delhi, India. He served research in the area of multiband antennas, filters, power divider and different metamaterial structures. He published more than seventeen papers in the reputed journals and conferences. He is also member of several technical societies such as the institute of Engineers (IE) India, Photonic society of India and Indian society for technical education (ISTE), India.
Muhmmad Shah Alam obtained his B.Sc. Engineering (Electronics & Communication Engineering) and M.Sc. Engineering (Electronics & Communication Engineering) degrees from Aligarh Muslim University (AMU), Aligarh in the year 1988 and 1991, respectively. He was awarded Queen's research fellowship, which is quite rare to obtain for non-European students, for carrying out research at the Queen's University of Belfast (UK) from where he obtained his PhD degree in Electronics Engineering in the year 2002. In the year 2010, he completed his post-doctoral study from the QUB, UK in the area of Nano-electronics under Commonwealth Fellowship Programme. In 1993, he joined the Department of Electronics Engineering, AMU, Aligarh, as a Lecturer, and in 1998 became a Sr. Lecturer. Since 2002, he served the department as a Reader and became an Associate Professor in 2006, and subsequently a Professor in 2009. His current research interests include •Millimeter Wave Circuits and their Battery-less ("Green") Operation for Internet-of-Everything (IoE) •Multi-band rf Circuit Design for Wireless Gigabit
Wireless Communication •Evaluation and Performance Comparison of Emerging Device Technologies •RF Models for GHz Circuits •Nanocomposite Materials for Supercapacitor and Antenna Applications. Dr. Alam is a Fellow of the Institution of Electronics and Telecommunication Engineers (IETE) (India). He is Senior Member of Institution of Electrical and Electronics Engineers (IEEE) (USA); Life Member of Indian Society for Technical Education (ISTE) and System Society of India. He has been a visiting scientist to: The Technical University Dresden, Germany from 20 November-19 December, 2014 under DFG-INSA Bilateral Exchange Programme; the University of Ottawa, Canada during 23-24 October 2010; Nano-technology Centre, QUB (UK) from December 2004 to February 2005 jointly Funded by the Royal Society of London (UK) & DST (Govt. of India) for encouraging collaborative research work between Excellent Young and Outstanding Scientists of UK and India. He collaborated with the Parthus Technologies Limited, Belfast (UK) and High Frequency Research Group at the QUB and the project entitled, ‘RF Modeling of Sub-micron CMOS for Radio Frequency Circuit Design’ in year 2002. Dr. Alam has successfully completed a major research project (₹23, 814, 00) in 2010 Funded by the Department of Science and Technology (DST), Govt. of India under National Mission on Nano Science and Technology. Dr. Alam collaborated with the QUB and completed the project entitled, ‘Design of Novel Nano-scale Devices for Low Power Application’ in year 2014. He was an Indian PI for the collaborative project entitled, ‘Performance Comparison of state-of-art CMOS and SiGe LNA for Multi-band Wireless’, with German PI: Prof. Dr.-Ing. Michael Schroeter, Chair for Electron Devices and Integrated Circuits, Technical University Dresden, Germany and successfully completed the project in year 2014, funded by INSA, Govt. of India, & DFG, Govt. of Germany. He has been to several countries including UK, USA, Canada, Denmark, France, Turkey and Singapore for the purpose of academic interaction or collaborative research. He has signed NDA for technology support from IHP Germany during 2019-2021 to carry out RF/Millimeter-Wave Circuit Design up to 300 GHz. He Chaired a Technical Session in 18th IEEE MTT-S Mediterranean Microwave Symposium (MMS-2018), Istanbul, Turkey, from 31 October-02 November 2018. He is a reviewer of number of reputed international journals including IEEE and IET. He has worked extensively in the areas of Millimeter Wave Circuit, RF device modeling and nano-electronics and published more than 60 research papers including reputed International journals like Microwave Optical Letter, International Journal of Electronics, and Solid-state Electronics. Dr. Alam has an interest in the teaching of courses like RF Circuits & Systems, Digital Electronics, Circuit Theory, Advanced Device Modeling, RF System Design, µWave Devices & ICs, µWave and Antenna and µWave Engineering.
Abstract- A miniaturized quad-band patch antenna for WiMAX/WLAN/GSM applications is presented in this paper. The proposed antenna structure consists two L-slots and a slit in the patch. The longer between two slots, resonates at 1.74 GHz (1.8 GHz band), whereas the shorter at 2.58 GHz (2.4/2.5 GHz band). The third and fourth resonances at 3.6 GHz (3.5 GHz band) and 5.6 GHz (5.2/5.5/5.8 bands) are due to the slit and length of the patch, respectively. A detail parametric analysis is carried out by varying the length of the slots (i.e. L-slots and slit) to achieve the desired frequency bands. An equivalent circuit model of the antenna is developed and the various antenna performances are analyzed. The antenna simulated results for return loss and 2D radiation patterns are experimentally verified.
1.
INTRODUCTION
There is a great demand to integrate various communication standards like GSM, WLAN and WiMAX applications into a single mobile unit [1].
The specified spectrum for WiMAX (IEEE 802.16) is 2.5 GHz
(2.5–2.69 GHz), 3.5/5.5 GHz (3.4–3.69, 5.25– 5.85 GHz), WLAN (IEEE 802.11) 2.4 GHz (2.4–2.484 GHz), 5.2/ 5.8 GHz (5.15–5.35, 5.725–5.825) and for 1.8 GHz GSM band is (1.710-1.880 GHz) [2] [11]. To fulfill these requirements number of multiband antennas are studied [2] [3]-[12]. They utilize several techniques such as metamaterials, meandering lines, cutting slots and fractal shapes to make their design compact. In [3]-[5], metamaterial multiband antennas were designed using hexagonal-shaped split ring radiating structure [3], etching of inverted L-slot in the monopole with additional reactive load [4], cutting a T-slot in the patch with meandered lines [5] open strip ring resonator as a radiating element [6] and tapered shaped radiating element and a meta-atom (complementary split ring resonator-CSRR) loaded in the ground plane [7]. Similarly, in [8], a triple band monopole antenna was realized by a tooth brush-shaped patch, a meander line, and an inverted U-shaped patch for WLAN and WiMAX applications. For the same applications, antennas were developed using fork shaped strip with a modified rectangular ring [9] and by loading a complementary right/left-handed unit cell [10]. The multiband antennas developed in [3]-[10] covers all the bands of WLAN and WiMAX but they are complex in design (thus higher cost). In [11], SRR-based polygon rings penta-band fractal antenna is used, which covers either single or dual bands of WLAN, WiMAX and GSM. Similarly, a compact size multiband antenna using asymmetric coplanar strip (ACS) feed has been developed for WLAN/WiMAX/ Bluetooth/ LTE but covers a single band for these applications [12]. The designs developed in [11] [12] are complex and all the bands of WLAN/WiMAX are not covered. Although, they do cover single band of GSM/ Bluetooth/ LTE [11] [12]. Therefore, in this paper, proposes to develop a more compact size (as compared to the earlier work [3]-[12] multiband antenna, which not only covers all the bands of WLAN/WiMAX but GSM band as well. The proposed antenna consists of a rectangular patch with two L-slots and a slit to generate four resonances, which are resonated at 1.74 GHz, 2.58 GHz, 3.61 GHz and 5.60 GHz covered all the bands of WiMAX/WLAN and 1.8 GHz GSM band. An equivalent circuit model of the antenna is developed for understanding the resonance and coupling behaviors. In the model, each resonance is represented by a tank circuit (parallel R LC) and mutual inductive coupling by LM. Using the technique described in [13]-[15], the model components value are theoretically estimated and further optimized in Keysight ADS [16] for reflection coefficient S11<-10dB. An input impedance (ZIN) expression by accounting asymptotic behavior at lower and higher frequencies is derived [17]. Furthermore, the power loss due impedance mismatch at each resonance frequency is determined. 2.
PROPOSED ANTENNA DESIGN
The proposed monopole multiband antenna has been designed on FR4 substrate with dielectric constant 4.4, loss tangent 0.02 and height of 1.6 mm. The antenna consists of partial ground plane with two L-slots and a slit in the patch as illustrate in Figure 1. The geometries of the antenna are optimized for the desired bandwidth with acceptable S11≤-10dB. The optimized size of the antenna is resonated at 1.74 GHz, 2.58 GHz, 3.6 GHz and 5.58 GHz, which are mainly due to the two L-slots, slit and patch, respectively. The antenna optimized geometries are given in Table I. The design flow of the proposed antenna is described in the flowchart given in Figure 2, which essentially involved four design steps. In the first step, a single band monopole antenna is designed, which resonates at 5.26 GHz as shown in Figure 3 (a). In the second step, dual band operation is achieved by cutting L-slot in the patch on the left side of the feed line, which is responsible for resonance at 2.58 GHz and 5.36 GHz as illustrated in Figure 3 (b). Similarly, in the third step, tri-band operation is achieved by cutting another L-slot to the right side of the slot in the previous design i.e. second step and three resonances at 1.74 GHz, 2.58 GHz and 5.36 GHz are achieved (See Figure 3 (c)). In the fourth step, an additional slit is introduced in the patch at the right side of the feedline and the final structure (i.e. patch with two L-slots and a slit) resonates at 1.74 GHz, 2.58 GHz, 3.6 GHz and 5.58 GHz as shown in Figure 3 (d). Thus, the proposed antenna has designed by the fourth step process. In the antenna, the length of the two L-slots as shown in Figure 3(d) (i.e. L12=13.60 mm, L34=19.90 mm) and slit (i.e. L5=10.82 mm) were found approximately equal to quarter guided wave length ( g/4) at 2.58 GHz, 1.74 GHz and 3.6 GHz, respectively. The proposed antenna has no ground plane underneath the radiating patch (with two narrow slots), therefore, the radiation patterns are bidirectional [18]. The occurrence of resonances in the proposed antenna are further examined with the help of surface current distribution [19] as shown in Figure 4(a)-4(c). In Figure 4(a), the higher current at1.74 GHz is mainly confined in the longer L-slot, which justify its role for the occurrence of resonance at this frequency. Similarly, as shown in Figure 4(b) and 4(c), shorter L-slot and slit are responsible for exitance of resonance at 2.58 GHz and 3.60 GHz, respectively. 3.
PARAMETERIC ANALYSIS
It has been observed in Section 2.0 that the first three resonance frequencies (1.74 GHz, 2.58 GHz and 3.60 GHz) are due the length of the slots/slit (namely L34, L12 and L5). The L34, L12 and L5 where found approximately equal to λg/4, where λg is the guided wavelength [20] as shown in Figure 3. By using guided wavelength λg/4 at 1.74 GHz, 2.58 GHz and 3.60 GHz were determines as 20.90mm,13.60mm 10.82mm, respectively. Now, their values are marginally perturbed to see their effect on each resonance frequency. As shown in Figure 5(a), when L34 is increased from 18.90 mm to 20.90 mm, then the first resonance frequency is decreased from 1.91GHz to 1.74 GHz, whereas the other resonances remain unaffected. With an optimum value L34 =19.90 mm, the first resonance observed at 1.74 GHz, which covers the 1.8 GHz GSM band. Similarly, as L12 is increased from 12.60 mm to 14.60 mm, then the second resonance frequency is decreased from 2.75GHz to 2.47 GHz, whereas the other resonances remain unaffected as shown in Figure 5 (b). With the optimum length L12=13.6 mm, the resonance occurred at 2.58 GHz, which covers 2.4/2.5 GHz bands. Furthermore, as L5 is
increased from 9.82 mm to 11.82 mm, then the third resonance frequency is decreased from 3.79 GHz to 3.26 GHz, whereas other resonances remain unaltered as shown in Figure 5 (c). With an optimum L5 =10.82 mm, the third resonance at 3.58 GHz covers 3.5 GHz band. As far as fourth resonance (5.64 GHz) is concerned, it remains unaffected by changes in L12, L34 and L5 and it covers 5.2/5.5 GHz and 5.8 GHz bands. Since the ground plane length Lg and width Wg affects the antenna performance, therefore a detail parametric studies by varying Lg and Wg have been carried out as shown in Figure 6 (a)-(b). By observing Figure 6(a), it can be concluded that by changing Lg has no effect on 1st and 2nd resonances, whereas higher resonances (i.e. 3rd & 4th) are affected. Similarly, by varying has no effects on all other resonances (i.e. 1st, 2nd & 3rd) except the minor change in 4th resonance is observed.
4.
EQUIVALENT CIRCUIT MODEL
To investigate the resonance behavior of the antenna, an equivalent circuit model is developed. By using the Foster’s representation, the lossless input impedance ZIN of the antenna can be expressed as [13]: jω
3
ZIN = ∑n = 0C
(
)
2 n ω2 n―ω
1 st term
+ jωLM12 + jωLM23 + 2nd term
3rd term
1 jωCs 4th term
+ jωLs
(1)
5th term
In Eq. (1), 1st term indicates the four resonances modelled as parallel LC tank circuits, whereas 2nd and 3rd terms i.e. LM12 and LM23 model the inductive coupling effect between the slots (L12 and L34 ) and (L34 and L5), respectively. The 4th term accounts for capacitive impedance 1/(jCS) for the asymptotic behavior of ZIN at low frequency, whereas 5th term represents the inductive impedance jLS to counter balance the 4th term effect at the high frequency. However, when losses are incorporated for each tank circuit and modelled as R0, R1, R2 and R3, respectively, then modified equivalent circuit obtained as illustrated in Figure 7. By accounting these resistances, the first tank circuit modelled (R0, L0 and C0) and its associated impedance Z0 can be expressed as:
Zo = (R
jωR0L0 0
(2)
― ω2R0L0C0) + jωL0
Similarly, 2nd, 3rd and 4th tank circuits are modelled as R1L1C1, R2L2C2 and R3L3C3 and their respective impedances as Z1, Z2 and Z3, respectively. By including the losses, the modified ZIN can be expressed as: 1
ZIN = Z0 + Z1 + Z2 +jωLM12 +jωLM34 + jωCs +jωLs
(3)
Using, Eq. (1)-(3), various components are theoretically determined as discussed in [12]-[14]. Thereafter, their values are optimized using Keysight ADS [16] for reflection coefficient S11<-10dB as shown in Figure 8. The optimized circuit components values are summarized in Table II. 5.
INPUT IMPEDANCE MISMATCH LOSS (IML)
The input power loss due impedance mismatch is quantified in terms of IML [18]-[19], which is expressed as: IML (dB) = 10log (1 ― |S11|2)
ZIN ― Z0
Where S11 = ZIN ― Z0
(4)
The power loss in the antenna design associated with impedance mismatch can be reduced by adjusting characteristic impedance ZO of the feed line close to ZIN. Since ZO strongly depends on the width of the feedline, which can be optimized to achieve the impedance match. The IML has been calculated at each resonance frequency and its values are given in Table III. 6.
RESULTS AND DISCUSSION
The prototype of the proposed antenna is developed and simulated results (return loss & 2D radiation patterns) are experimentally verified. As shown in Figure 9, that the measured frequency range are (taken at S11@-10dB): (1.64-1.89 GHz), (2.39-2.70GHz), (3.4-3.7GHz) and (5.15-6.19GHz), which cover 1.8GHz band of GSM and all the bands of WLAN and WiMAX. The simulated and measured 2D radiation patterns at different resonance frequencies (i.e. 1.74 GHz, 2.58 GHz, 3.6 GHz and 5.58 GHz) are shown in Figure 10. It can be observed from Figure 10 that the simulated and measured radiation patterns slightly differ at these frequencies, which are mainly due to fabrication & measurement errors. As shown in Figure 11, the proposed antenna achieved the gain (efficiency) as: 1.70 dBi (94.30%), 1.8dBi (94.25%), 2.61 dBi (90.44%) and 2.86 dBi (92.83%) at 1.74 GHz, 2.58 GHz, 3.6 GHz and 5.58 GHz, respectively. The performance comparison of the proposed antenna with the reported works in literature in terms of size, frequency bands, gain and bandwidth are summarized in Table IV. As observed from the Table IV that the proposed antenna in this work is compact in size, which can be profitably utilized in the form of array for wireless power transmission application [21].
7.
CONCLUSIONS
In this paper a compact size multiband antenna has been designed for WiMAX, WLAN and GSM applications. The multiband operation of the antenna is achieved by cutting two L-slots with a slit in the radiating patch. The simulation results for return loss and radiation patterns are experimentally verified. An equivalent circuit model is developed to analytically analyze the antenna performance. The antenna proposed in this work demonstrates bidirectional and omnidirectional radiation patterns at E and H plane, respectively. Since the proposed antenna is compact in size with omnidirectional radiation pattern, which justify its suitability for wireless communication system. 8.
ACKNOWLEDGEMENTS
The authors appreciate the financial support received under TEQIP-III for the expenditure incurred by using Antenna Measurement Lab Facility at the Indian Institute of Technology (IIT), Kanpur, India.
REFERENCES 1. Ketavath Kumar Naik, Asymmetric CPW-fed SRR patch antenna for WLAN/WiMAX applications, International journal of electronics and communications (AEÜ), 2018, 93, 103-108. 2. Yan Zhang and Nirwan Ansari, Wireless telemedicine services over integrated IEEE 802.11/WLAN and IEEE 802.16/WiMAX networks, IEEE wireless communications, 2010, 30-36. 3. S. Imaculate Rosaline and S. Raghavan, Metamaterial inspired monopole antenna for WLAN/WiMAX applications, Microwave and optical technology letters, 2016, 58, 936-939. 4. H. Huang, Ying Liu, Shaoshuai Zhang and Shuxi Gong, Multiband metamaterial-loaded monopole antenna for WLAN/WiMAX Applications, IEEE antennas and wireless propagation letters, 2015,14, 662-665. 5. Pratyush Pushkar and Vibha Rani Gupta, a metamaterial-based tri-band antenna for WIMAX /WLAN application, Microwave and optical technology letters, 2016, 58, 558-561. 6. Rengasamy Rajkumar and Kommuri Usha Kira, A metamaterial inspired compact open split ring resonator antenna for multiband operation, Wireless personal communications, 2017, 97, 951–965. 7. Rajeshkumar Venkatesan, Rajkumar Rengasamy, Praveen Vummadisetty Naidu and Arvind Kumar, A compact meta-atom loaded asymmetric coplanar strip-fed monopole antenna for multiband operation, International journal of electronics and communications, 2019, 98, 241-247. 8. Yingsong Li andWenhua Yu, a miniaturized triple band monopole antenna for WLAN and WiMAX Applications, Hindawi publishing corporation international journal of antennas and propagation, 2015, 1-5. 9. Li Li, Xiaoliang Zhang, Xiaoli Yin and Le Zhou, a compact triple-band printed monopole antenna for WLAN/WiMAX applications, IEEE antennas and wireless propagation letters, 2016, 15, 1853-1855. 10. Sourav Nandi and Akhilesh Mohan, CRLH unit cell loaded triple band compact monopole antenna for WLAN/WiMAX applications, Microwave and optical technology letters 2017, 59, 686-691. 11. V. Rajeshkumar and Singaravelu Raghavan, SRR-based polygon rings penta-band fractal antenna for GSM/WLAN/WIMAX/ ITU band applications, Microwave and optical technology letters, 2015, 57, 1301-1305. 12. Praveen V. Naidu, Printed V-shape ACS-fed compact dual band antenna for bluetooth, LTE and WLAN/WiMAX applications. Microsystem technologies, 2016, 23, 1005–1015. 13. Michael Hamid and Rumsey Hamid, Equivalent circuit of dipole antenna of arbitrary length, IEEE Transactions and Propagation, 1997, 45, 1695-1696. 14. F. Gronwald, S. Gluge, and J. Nitsch, On network representations of antennas inside resonating environments, Advances in radio science, 2007, 5, 157-162. 15. A.K. Gangwar and M. S. Alam, A SSRR based multiband antenna for mobile phone, 2016 Twenty second national conference on communication (NCC), IIT Guwahati, 2016, 1-4. 16. Keysight Advanced Design System (ADS) 2019; www.keysight.com 17. A. K. Gangwar and MS Alam, CSRR based folded monopole tri-band antenna array and its system level evaluation, International journal of RF and microwave computer aided engineering 2018, 1-9. 18. Robert E. Collin, Antennas and radio wave propagation, McGraw-Hill, 1985, 6. 19. Thomas A. Milligan, Modern antenna design john wiley & Sons, 2005, 17-18. 20. A. K. Gangwar and MS Alam, A high FoM monopole antenna with asymmetrical L-slots for WiMAX and WLAN applications, Microwave and optical technology letters, 2017, 60, 196–202. 21. A. F. Morabito, Synthesis of maximum-efficiency beam arrays via convex programming and compressive sensing, IEEE Antennas and wireless propagation letters, 2017, 16, 2404-2407.
(a)
(b)
Figure 1. Geometry of the proposed antenna (a) top view (b) bottom view (c) side view.
(c)
Start
Determine the antenna dimensions using the given specifications Simulation using Keysight ADS
A monopole patch antenna is designed for single band (StepI)
For dual band operation, L-slot is cut in the patch of the monopole antenna from left side of the feed line (Step-II).
To operate the previous design (realized in Step-II) for triband operation, another L-slot is cut on the right side of the feed line (Step-III)
Optimum Results
For quad-band operation, an additional slit is introduced in the design obtained in Step-III, to the right side of the feed line (Step-IV)
No
Yes Fabrication process begins after the simulations results are optimized Return loss and radiation pattern measurement Comparison of simulated measurement results
and
End
Figure 2. Flow chart of the proposed multiband antenna design containing all the four basic steps involved.
(d) (c)
Returnloss (dB)
(a) (b)
(a)
(b)
(c)
(d)
Frequency (GHz) Figure 3. Simulated S11 for (a) monopole patch antenna (b) antenna with L12 slot (c) antenna with L12 and L34 slots (d) proposed antenna i.e. antenna with L12 and L34 slots and slit L5.
(a)
(b)
(c)
Figure 4. Surface current distribution of the proposed antenna at (a) 1.747 GHz (b) 2.58 GHz (c) 3.61 GHz.
0
(c)
Returnloss (dB)
-5 -10 -15 -20
L5=9.82 mm
-25
L5=10.82 mm -30
L5=11.82 mm
-35 0.5
1.5
2.5
3.5
Frequency (GHz)
4.5
5.5
6.5
Figure 5. Simulated S11 of the antenna by tuning the different value of (a) L34 (b) L12 (c) L5.
0
(a)
-5
S11 (dB)
-10 -15 -20 -25 Lg=7.88 mm Lg=8.38 mm Lg=8.88 mm
-30 -35 -40 0.0
1.0
2.0
3.0 4.0 Frequency (GHz)
5.0
6.0
0
(b)
-5 -10
S11 (dB)
-15 -20 -25 -30 -35 Wg=15.9 mm Wg=16.4 mm Wg=16.9 mm
-40 -45 -50 0.0
1.0
2.0
3.0 4.0 Frequency (GHz)
Figure 6. Simulated S11 of the antenna by tuning the different value of (a) Lg (b) Wg
Figure 7. Equivalent circuit model of the antenna
5.0
6.0
0
Returnloss (dB)
-5 -10 -15 -20 -25 Equivalent circuit
-30
Proposed Antenna
-35 0.5
1.5
2.5
3.5
4.5
5.5
Frequency (GHz)
Figure 8. Simulated S11 of the antenna and its equivalent circuit model.
Figure 9. Simulated and measured S11 of the antenna.
6.5
(a)
(b)
(c)
(d)
4.5
96
4
94
Returnloss (dB)
3.5
92
3
90
2.5
88
2
86
1.5 1 0.5
Gain
84
Efficiency
82
0
80 0.5
1.5
2.5
3.5
4.5
5.5
Frequency (GHz) Figure 11. Simulated gain and efficiency of antenna.
6.5
Efficiency (%)
Figure 10. Simulated and Measured (left) E-plane and (right) H-plane radiation pattern of the antenna (a) 1.74 GHz (b) 2.58 GHz (c) 3.61 GHz (d) 5.6 GHz
TABLE-I Dimensions of the antenna
Parameters Values (mm)
WF 2.20
Lf 11.30
WP 16.0
LP 12.70
L1 4.87
L2 9.13
L3 9.91
L4 11.07
L5 10.82
g 0.20
Wg 16.4
Lg 8.38
TABLE-II Optimized parameters of the equivalent circuit model
Parameters Values Parameters Values
R0 (Ω) 158.39 C2 (pF) 2.79
L0 (nH) 1.28 R3 (Ω) 35.07
C0 (pF) 0.94 L3 (nH) 1.62
R1 (Ω) 203.30 C3 (pF) 7.08
L1(nH) 2.35 LS (nH) 0.94
C1 (pF) 2.13 CS (pF) 0.92
R2(Ω) 229.08 LM1(nH) 0.82
TABLE-III Comparison of measured and simulated IML with ZO=50Ω
Measured
Simulated
Frequency (GHz)
S11 (dB)
IML(dB)
1.76 2.56 3.56 5.88 1.75 2.60 3.62 5.65
21.7 28.3 24.4 15.2 19.9 18.1 25.4 13.9
0.029 0.006 0.016 0.133 0.045 0.068 0.013 0.181
L2(nH) 0.93 LM2(nH) 1.91
TABLE-IV Comparison of performances between the proposed antenna and reported work in literature Ref.
L×W×h (mm3 ) (Year)
[2]
24×22.5×0.8 (2016)
[3]
45×40×1.0 (2015)
[4]
35×35×1.0 (2015)
[5]
27.5×16.08×1.6 ( 2017)
[6]
25×12.2×1.6 ( 2019)
[7]
30×20×0.8 (2015)
[8]
34×18×1.6 (2016)
[9]
20×21×1.57 (2017)
[10]
24×18×1.6 (2015)
Proposed Antenna
24×16.4×1.6
Frequency (GHz) 2.45 3.5 5.2 5.8 2.44 3.5 5.5 2.6 3.5 5.5 2.41 4.10 5.38 2.4 5.2 5.8 7.4 2.4 3.5 5.5 2.5 3.5 5.5 2.51 3.55 5.73 1.9 2.6 3.5 5.2 1.74 2.58 3.61 5.60
Gain (dBi)
B.W (MHz)
2.50 2.14 3.30 3.50 3.20 2.38 2.34 1.65 2.59 3.94 0.37 1.61 1.88 4.98 1.06 0.88 2.17 1.30 2.20 3.00 0.28 1.42 4.76 1.29 2.44 3.26 0.25 3.8 4.3 1.13 1.70 1.80 2.61 2.86
130 330 1540 1700 1600 280 760 700 80 200 2800 1100 2240 660 140 310 840 300 300 1000 210 300 1390 150 500 700 5050 220 320 330 810
Declaration of interests
☐ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
☐The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:
Ajay Kumar
Corresponding Author (Ajay Kumar Gangwar)