An LPTV Programmable Bandpass True-time-delay Line Without External Clock-phase Shifter

This work presents a programmable, linear, periodically time-variant (LPTV) bandpass true-time-delay line which does not require a dedicated tunable clock-phase delay generator. The architecture provides true-delays, which are independent of the time-period of the clock to passband signals, and out-of-band (OOB) blocker attenuation due to its bandpass nature. It operates by embedding a programmable order linear-time-invariant (LTI) delay-line within the switches of an N-path structure, thus translating the low-frequency delay to the RF. Simulation results point to a realizable programmable delay between 3-6 ns for center frequencies between 1-5 GHz over an RF bandwidth of 100 MHz.