Multi-band RF time delay element based on frequency translation

Design of tunable multi-band time delay elements based on frequency translation is presented. The proposed topology exhibits time delay of multiple periods of the RF carrier. Two possible implementations of the proposed idea are presented and simulation results are shown for one such implementation. The implemented circuit exhibits an envelope delay of 2.5 ns with the RF carrier delay tunable from 0° to 360° in 45° steps in the 2.4 GHz ISM band.