A portable scalar network analyzer for the flight line environment

The authors describe an RF transmission-line test-set, the AN/USM-638, which is a state-of-the-art, portable, fully militarized, scalar network analyzer designed specifically to support the maintenance of coaxial and waveguide transmission systems. The frequency range of this system is 0.01 to 18.0 GHz with growth capability to 40.0 GHz. Utilization of microwave circuit integration including monolithic microwave integrated circuit (MMIC) devices as well as field programmable gate array (FPGA) technology played an important role in producing a downsized composite system for the measurement of insertion loss (0 to -70 dB), distance to fault (to 400 ft), and voltage standing wave ratio/return loss (0 to 25 dB). Successful development of the AN/USM-638 provides the means to significantly enhance the test capabilities of the US Air Force´s organizational level test equipment, thereby improving the operational readiness of weapons systems