A novel analog 360° phase shifter design in Ku and Ka bands

This paper presents a new 360° analog phase shifter for Ku and Ka bands applications. These devices are reflection-type analog phase shifters implemented with a 90° branch-line coupler and a new load concept. Varactor diode is used as the tuning element to change capacitance with voltage. Test circuits have been optimized, in order to have 360° phase shift range with low insertion loss. The measured Ku band phase shifter presents more than 360° phase shift between 11.5 and 12.5 GHz. At 12 GHz the insertion loss is 3.3dB+/−0.5dB. For the Ka band example, the lowest insertion loss is obtained at 30.3 GHz (3.6dB+/−1.8dB) and the phase shift is 315°. In both case, the return loss is always lower than −10dB.