Gallium nitride to revolutionise wireless

News Update

Technology: Microelectronics

Simulation augers well

Gallium Nitride to revolutionise wireless U m e s h Mishra, professor of

m i c r o w a v e transmission f r o m

electrical and c o m p u t e r engi-

base station to cell p h o n e and

same a m o u n t of p o w e r b u t

Herley Industries, Inc. based in

neering at the University of

o t h e r wireless technologies.

smaller size, a device has l o w e r

Lancaster, Pennsylvania,

California at Santa Barbara and

received a $1.5m contract

Cornell University's Lester

award to design and develop

Eastman have w r i t e n on gallium

h a r d w a r e in s u p p o r t of a verti-

nitride 'The Toughest Transistor

cal launch missile p r o g r a m m e .

Yet' for IEEE Spectrum, May.

After development, p r o d u c t i o n options could increase the total contract award to m o r e than $5m.The c o m p a n y is believed to be expanding its UK and Israel facilities following improved international sales related to increased operating t e m p o of fighter aircraft and the acquisition of UK defence electronics firm EW Simulation Technology, Ltd. Herley supplies innovative, and sophisticated RE microwave and millimeter wave c o m p o nents and s u b s y s t e m s to the defense and aerospace industries. Its expertise in pulsed and continuous-wave microwave amplifiers and related technolo-

w i d e b a n d gap b e t w e e n the valence and c o n d u c t i o n bands

capacitance. The smaller the device, the faster the energy can move out of it.

of the semiconductor. The larg-

GaN transistors will look like

er the b a n d gap, the m o r e volt-

transistors made of o t h e r semi-

Mishra's and Eastman's research

age that can be applied. GaN

conductors, b u t p e r f o r m m u c h

g r o u p s have made a Field Effect

enables a transistor that can

better. "That is always appealing

Transistor (FET) out of GaN,

handle high voltage and high

for a d o p t i o n of the technology

w i t h Mishra making a bipolar

current. So the p r o d u c t p o w e r

because you d o n ' t have to re-

transistor. GaN's p r o m i n e n c e as

goes u p b e t w e e n 10 and 100

educate p e o p l e on h o w to use

the m o s t promising c o m p o u n d

times over silicon or GaAs. For

it. In effect, the b o x will look

s e m i c o n d u c t o r is due in large

a c o m m u n i c a t i o n s device, high-

the same, the h u m a n interface

m e a s u r e to the w o r k of

er p o w e r enables greater range

w i t h the b o x will be the same,

Professor Shuji Nakamura, w h o

of transmission or smaller trans-

b u t w h a t is inside will p e r f o r m

used GaN to create the first

mission devices.

m u c h better," he says.

blue, green, ultraviolet, and w h i t e LEDs, and a blue laser. Mishra and his UCSB colleagues have w o r k e d on electronic devices w h e r e GaN, used for electronic devices, has piggybacked on advances made by the optical researchers as forecast by Mishra.

gies finds use in nuclear mag-

GaN electronics are n o t as daz-

netic r e s o n a n c e and magnetic

zling as replacing the incandes-

resonance imaging systems.

cent light bulb and not a

The c o m p a n y has over 32% of

r e p l a c e m e n t for ubiquitous sili-

its revenues c o m i n g from inter-

c o n FETs that make u p c o m p u t -

national c u s t o m e r s in fiscal

ers. The target for GaN transis-

2002 and e x p e c t s this market

tor r e p l a c e m e n t is GaAs, w h i c h

to continue to grow.

rocketed to p r o m i n e n c e w i t h

Flixel, Israel needs RF design partner

Gallium Nitride crystals

Mimix buffer amplifier MimLx Broadband Inc intro-

band w h e n biased for l o w

duces its GaAs MMIC three

noise.This device also has 20

stage buffer amplifier, w h i c h

dBm PldB c o m p r e s s i o n p o i n t

An RF design p a r t n e r is n e e d e d

included within the switch

can be operated w i t h all three

at high p o w e r bias, and greater

by FILxel, an Israeli SME, w h i c h

area saving area-consuming

stages biased in parallel, or w i t h

than 30dBm OIP3.

has developed a u n i q u e MEMS

actuators. While technological

i n d e p e n d e n t bias for input and

A high dynamic range amplifi-

(Microelectromechanical

barriers are very high, produc-

o u t p u t stages to optimise per-

er, identified as XBIO03, it

System) Hinge and Flipper for

tion entry barriers are

formance. Using 0.15-micron

serves as an excellent LNA, LO

High Reliability microswitches.

practically non-existent due

gate length GaAs PHEMT

driver, saturated or linear buffer

These can be used in p h a s e d

to the ability to use of existing

device m o d e l technology, this

amplifier, well suited for wire-

array antennas, RF e q u i p m e n t ,

p r o c e s s and foundries.

buffer amplifier covers the 16

less c o m m u n i c a t i o n s applica-

cellular base stations, cell-

Flixel is seeking to cooperate

to 29GHz frequency bands and

tions s u c h as m m -wave point-

p h o n e s for xDSL and o t h e r

w i t h p a r t n e r s to finalise the RF

can be biased for l o w noise or

to-point radio, local multipoint

wireline telecom applications,

design and commercialise the

high p o w e r p e r f o r m a n c e . T h e

distribution services, SATCOM

The hinge is based on a no-tor-

product.

device has a typical small signal

and VSAT applications.

sion/no-friction design and

Contact:chana n @ m a t i m o p . o r g . il URL: h t t p : / / w w w . i r c . o r g . i l

gain of 23dB w i t h a typical

Contact: jteinert@ mimixbroadband.com

the actuation m e c h a n i s m is

16

W h a t GaN has going for it is a

Mishra explains that w i t h the

noise figure of 2dB across the

III-Vs REVI EW THE ADVANCED SEMICONDUCTOR MAGAZINE VOL 16 - NO 4 - MAY 2003