A 0.5-3GHz True-Time-Delay Phase Shifter for Multi-Antenna Systems

A 0.5-3GHz true-time delay (TTD) phase shifter circuit is implemented. Basing on active delay cells and active switches, the coarse delay is achieved. The LC artificial transmission line (ATL) provides continuous delay. The delay variation of the total delay is less than 2.4% Using broadband matching and shunt peaking techniques, larger bandwidth and flatter group delay is obtained in phase shifter. The achieved relative total delay is from Ops to 92 ps. And the return loss of the circuit is better than-10dB. The core occupies of the TTD phase shifter with 1/0 pads is less than 0.63mm(2) in a 0.18-mu m CMOS technology.