Ka-band 4-bit phase shifter with low phase deviation

Phase shifter is a key component of phased array antenna. By using the GaAs PIN switches, a Ka-band 4-bit switched-line digital phase shifter, including its topology, phase error, phase tuning, and measured results, is described. The emphasis is to reduce the phase error. In frequency bandwidth 2GHz, the developed phase shifter demonstrates an overall phase deviation less than 3.9° rms with 3° rms at the designed center frequency, and the insertion loss is about 8.3±1.7dB. It is proved that the way of phase tuning is effective.