Active phase shifter module for satellite communications at Ka-band

In this paper, the design and fabrication approach for a lightweight, 4 input/1 output active phase shiner module (APM) for Ka-band satellite communication is presented. Each channel is combined using the Wilkinson power combiner which is on the alumina substrate (ε_r = 9.9, thickness = 5 mil). The APM is composed of voltage variable attenuators, 5-bit phase shifters, SSPA and DC circuit. Each gain of the 4-channel APM is about 12.5 dB at initial phase state and variations of all the gains are within ±1 dB, when the phase states are changed. Measured phase error and P₁ dB of the APM are average ±4.4° per bit and 22 dBm, respectively.