Belying the realities of a difficult economic environment a record 72 delegates attended the November ARMMS RF & Microwave Society Conference at the Rockingham Forest Hotel in Corby, UK, which was sponsored by Teledyne Labtech. In all fifteen papers on a wide range of microwave technologies were presented and highlights included a very clear explanation of Campbell’s adaptation of the Cripps' method of RF power amplifier design.
Charles Suckling of TriQuint showed how a GaN HEMT PA was optimized to evenly distribute RF power across the four cells in the TGF2023-05 device. Measured gain was over 11 dB at 10 GHz with over 10 W of output power. The need for very careful EM simulation of the matching circuits was emphasized by the speaker and this technology has the potential to open up new applications such as low cost solid-state marine radar.
Emphasizing the strength of academic representation, Dr. Nerijus Riauka of Loughborough University, UK, presented a patented design of a 470 to 850 MHz low cost antenna. A dipole was realized on low cost FR4 PCB material together with a balun. To increase the bandwidth parasitic elements are added and the whole design validated with EM simulation. The simulation showed that good pattern, adequate return loss and good efficiency of around 90 percent were achieved. In addition examination of the distributed simulated currents demonstrated the effectiveness of the PCB balun. This design is now being commercially exploited by Antrum Limited.
ARMMS originally began in 1984 with a focus on microwave measurements. This tradition was maintained by Thomas Reichel, who presented detailed techniques employed by Rohde & Schwarz to achieve precise power measurements. Modern power sensors are complete instruments without the need for a meter unit. They utilize three separate thermoelectric and diode sensor elements to give a 90 dB dynamic range, with signal processing intelligently combining the separate signals. For very precise measurements the measured reflection coefficients of the sensor are stored within it and used to correct for gamma match. Equal care was applied to the mechanical design of the connector to ensure a repeatable connection.
The recipient of the Steve Evans-Pughe Prize for best speaker, which was voted for by attendees went to Dr. Javier Vazquez of Cobham Technical Services. He introduced the concept of a non-reciprocal antenna which is capable of transmitting with one polarization and receiving with another. This result was achieved under the AMULET project, which is investigating meta-materials.
Alongside the conference twenty exhibitors displayed products, including Aeroflex, Q-Par Angus, BSC Filters and National Instruments. The exhibition provided opportunity for discussion on a wide range of topics, from the latest sexless connector technology to the use of histogram techniques in spectrum analyzer displays. There was also the opportunity to network, and more, during the Society Dinner.