S-Band, 3-Bit, 1 KW Peak, 0.8 DB Average Loss, Diode Phase Shifter and Driver Under $100

There is a need for an S-band high power electronic phase shifter with low insertion loss and low cost for ground and ship-based phased array RADARS. Both diodes and ferrites are candidates for this application. Typically, the ferrite phase shifter is known to have low insertion loss; however, the recent use of wafer glassed PIN diodes removes the necessity for an expensive ceramic diode package and, furthermore, improves performance by eliminating diode package parasitic reactance. With these diodes, a complete 3-bit phase shifter having only 0.8 dB of average insertion loss has been made. This device has a rated power of 1 kW peak (the burnout level is 4 kW peak) using 120 microsecond-long pulses and 0.05 duty cycle. This paper describes the construction and testing of the phase shifter and a cost estimate for large quantities.