The European journal for the
microwave and
wireless design engineer
March 2005
In Focus:
Integration
sets the scene in Cannes
- Antenova, Texas Instruments, Analog Devices, Flarion, Harris,
PicoChip, Philips Semiconductors, Braodcom, Agilent Technologies,
Anite Telecoms, Wiltek Communications, Aeroflex, Tektronix.
Cover
feature:
Wideband
amplifier and prescaler modules cover DC to
20GHz
- Norm Hildreth, Hittite Microwave
Technology Focus: MEMs and
Micromachined Devices
MEMS
switch loses its spring
- Innos, GAAS Symposium, LG Electronics Institute of Technology
Application Focus: Low Power
Radio
Robust
wireless modem uses DSP and ISM band transceiver
- Patrick Butler and Austin Harney, Analog Devices
ZigBee
steers course for marine
applications
- Ember, Zignee Alliance, IEE Colloqium
Predicting
out-of-band non-linear power amplifier stability using hot
S-parameters
Joel Dunsmore and Wayne Smith, Agilent Technologies
Hot S-parameters, particularly hot S22, have previously been
described as an analogue to load-pull measurements. However, their
usefulness in replacing load pull for amplifier design has not been
demonstrated. In this paper, hot S-parameters are used in a different
way. A large RF signal is used to 'bias' an amplifier into a
large-signal state; the hot S-parameters are then measured in the
out-of-band region of the amplifier, from which amplifier stability
is predicted. The method was verified experimentally by applying
appropriate loads on the amplifier, and measuring spurious
oscillations at the frequencies where instability was
predicted.
Preliminary
direction finding results for a low cost HF ESM
system
GD Morgan, WP Jones, PW Stanley, SP Evans, QinetiQ
Communications Electronic Support Measures (ESM) require systems that
are capable of both a high Probability of Intercept (POI) and
accurate Direction Finding (DF) of radio emitters over a wide dynamic
range. The nature of the High Frequency (HF) environment makes
stringent demands on a broadband surveillance system. A novel HF ESM
system has been developed that exploits commutated techniques to
realise a low cost solution. This paper describes the developed
hardware and shows that it offers simultaneous high POI and wide
dynamic range without compromising DF
accuracy.
