RS Microwave Technical Corner

RS Microwave specializes in the design and manufacturing of high quality RF and Microwave filters for commercial and military applications.  Many of our products are designed for high power and require extensive testing and certification.  We are staying true to the motto of our company "We Duplicate What We Simulate”™, if we build for high power – we test for high power.  RS Microwave is one of the few filter companies that not only actively invests in research and development, but also builds its own testing equipment.  Using advanced design techniques and advanced simulation programs like Ansoft Designer and HFSS, we have built high power amplifiers for JTIDS/MIDS program band, UHF band, and currently in the final building stages of the amplifier for TTNT program.

Figure 1: RS Microwave technician con-ducting a high power test for JTIDS/MIDS

Shown below is a typical block diagram of the High Power Amplifier.

That particular amplifier was designed for UHF frequency band providing over 2.5kW of peak power with theoretical capability of 1.8kW average power (limited due to existing DC power supply).

The overall efficiency of over 50% was achieved.  Amplifiers for JTIDS/MIDS programs provide over 2kW peak power.  The upcoming amplifier for the TTNT program will have over 500W peak and 120W average power output, in the bands 1350-1550 and 1700-1900 MHz. All high power amplifiers our company builds have temperature control and shutdown capability, as well as test points for quick and reliable troubleshooting.   We use diverse design techniques in order to achieve high efficiency and high reliability amplifiers.  Various techniques have been used in the design of power division/combining such as Wilkinson, Gysel, Quadrature and Reactive networks.  In the UHF HPA, we have used 3 kinds of power combining techniques utilizing the advantages of each one.  In Figure 3 is shown a typical Distribution driver Amplifier Unit, utilizing FET transistors and Gysel power divider/combiners.

Power Amplifier Modules were designed using Push-Pull BJT power amplifiers that were combined using 3dB Quadrature couplers.  Quadrature couplers are an excellent way for power distribution due to a high isolation and high power capability.  In Figure 4, a typical power module is shown.  For the output a Reactive power combiner was used due to a very high power handling capability, low insertion loss, and capability to expand in the future if the need will rise for a higher power output.

At RS Microwave we are constantly looking to improve our design manufacturing and expand our capabilities.  As many more interesting and challenging filter designs will be coming, RS Microwave will require and will obtain advanced testing capabilities.