A Hybrid Integrated L-Band Digital Phase Shifter

This paper presents a description of an L-band dual-channel seven-bit phase shifter which has been developed for a phased-array application. Each channel provides seven-bit phase shifting capability over a 360° range in 2.8° increments. The outputs from the two channels are summed in a combiner which has also been integrated into the overall assembly. The performance requirements for the assembly are as follows: Bandwidth 15%, RMS deviation from nominal phase ≤ 3.5°, RMS deviation from mean loss ≤ 0.35 dB, Return loss at each port ≥ 17 dB. Since this unit would be utilized in large numbers in its intended application and since there are a large number of phase states, it was advantageous to define the unit-to-unit similarity in terms of RMS deviations rather than peak-to-peak limits.