F.E. van Vliet

Set of X-band distributed absorptive limiter GaAs MMICs

A set of X-band absorptive limiter GaAs MMICs has been designed and realised using both the PPH25x foundry process from UMS and the PP50-10 process from WIN semiconductors. The innovative limiter concepts have been extensively characterised by both pulsed and CW measurements. Both passive and active topologies have been implemented. The passive limiter design has a typical small-signal insertion loss of 1.5 dB at 10 GHz, and it can withstand (absorb) up to 4 Watts (36 dBm) of CW power without degradation or damage, while keeping the output power level below 100 mW (20 dBm). The active limiter handles up to 10 Watts of CW input power, at the cost of higher small-signal insertion loss. For all designs the input reflection remains low for any input power level. The used GaAs surface ranges from 2 to 3 mm2 .

X-Band GaN SPDT MMIC with over 25 Watt Linear Power Handling

Single pole double throw (SPDT) switches are becoming more and more key components in phased-array radar transmit/receive modules. An SPDT switch must be able to handle the output power of a high power amplifier and must provide enough isolation to protect the low noise amplifier in the receive chain when the T/R module is transmitting. Therefore gallium nitride technology seems to become a key technology for high power SPDT switch design. The technology shows good performance on microwave frequencies and is able to handle high power. An X-band SPDT switch, with a linear power handling of over 25 W, has been designed, measured and evaluated. The circuit is designed in the coplanar waveguide AlGaN/GaN technology established at QinetiQ.

Design and Analysis of a 34 dBm Ka-Band GaN High Power Amplifier MMIC

This paper presents the design and analysis issues related to the use of recent GaN technologies for realizing high power millimeter wave MMICs. Two GaN Ka-band amplifier MMICs have been designed, fabricated and characterized. The small-signal and power measurement results are presented for both amplifiers, with an excellent output power of 34.1 dBm at 27 GHz for the 2-stage power amplifier MMIC. Both MMICs have a very good yield and performance, even more so in regard of the current state-of-the-art. The observed deviations between the original simulation and measurements have been explained by extensive use of 3D EM simulations of the coplanar passive structures

Trends in wideband phased-array front-ends F.E. van Vliet TNO Defence, Security and Safety, P.O. Box 96864, 2509 JG, The Hague, The Netherlands

Wideband phased-array front-end technology is characterised by stringent specifications, increasing cost-pressure and is subject to fundamental changes. This paper addresses trends observed for these systems, both in relation to the functionality required (including the architecture of the system and the platforms upon which they are applied) as well as in relation to the technologies that may be employed.