An all-pass true time delay circuit for wideband phased array application

In this work, we present an all-pass true time delay circuit realized in TSMC 65nm CMOS LP technology for wideband phased array application. The circuit is based on first order Pade Approximation and designed in a switched line topology. It exhibits a relative time delay of 1.22-ps to 13.42-ps at 24.25-26.65-GHz and the resolution of 1.22-ps is equivalent to the accuracy of 5-bit phase shifter. It is the first wideband TTD phase shifter in CMOS technology at frequency up to K-band. The power consuming is rather low as 6.8-mA from a 1.2-V power supply.