This page contains additional information about some of our microwave and mm-wave designs.
Microwave GaN PAs using SMT plastic packaged discretes
The use of over-molded SMT plastic packaging greatly simplifies handling and assembly and reduces unit cost. However, as operating frequencies and RF output power increase so do the challenges of using SMT packaging. GaN transistors are now commercially available in SMT plastic packages and Plextek RFI has experience of developing PAs operating at X-band using such. The link below provides details of one particular example, an amplifier optimized 9.3 to 9.5GHz band with 11dB small signal gain and an RF output power of more than +37dBm and 55% drain efficiency at 3dB gain compression. The PA also includes fast drain switching circuitry to facilitate pulsed operation with a turn-on time of just 20ns.
E-band MMICs for Line-of-sight links
E-band spectrum at 71-76GHz and 81-86GHz offers worldwide availability of a large amount of spectrum under a “light license” basis. Whilst the challenges of designing components and sub-systems operating at E-band are significant the potential benefits of using E-band are very attractive for bandwidth hungry applications such as very high data rate point to point links for mobile communications back-haul. Plextek RFI has developed E-band MMICs including image reject mixers, single-sideband upconverters, VVAs and amplifiers using commercially available IC processes. We have the expertise to help you develop commercially viable E-band components and sub-systems.
As solid-state Power Amplifier (PA) technology continues to grow in maturity and capability the replacement of tube based devices with solid-state PAs has become increasingly viable. Plextek RFI was able to assist a client in replacing a magnetron based X-band radar with a solid-state system undertaking parts of the radar system design and the complete development of a 200W solid state PA. The PA was capable of CW operation but its intended use was pulsed with short rise times (<10ns) and a variety of duty cycles. Plextek RFI’s solution was based on mature GaAs MESFET devices and low loss power combiners. The resulting amplifier required an input drive of just 20mW to deliver 200W to a waveguide output.
Front-end modules for FMCW radar
Frequency Modulated Continuous Wave (FMCW) radars are capable of measuring distances to high levels of accuracy and detecting small targets with lower levels of peak transmit power than conventional pulsed radar. Plextek designed and developed the Blighter FMCW radar. This work included the development of the Ku-band components and subsystems used to implement the microwave front-end. Ku band components developed by Plextek RFI include an LNA-filter module with 26dB gain and 2.5dB NF, a 6W PA module with temperature compensated biasing, an image reject IQ downconverter with integral LO driver amplifier, a DDS based synthesiser to allow ultra-linear frequency sweeps and a single-sideband upconverter.