High-efficiency frequency doubler with a compensated transformer-based input balun

摘要

The disclosed embodiments relate to the design of a high-speed frequency doubler circuit. During operation, the circuit uses a transformer-based balun to convert a single-ended input signal into a differential signal, wherein the transformer-based balun includes a transformer with a primary coil, which receives the single-ended input signal, and a secondary coil, which produces the differential signal. The transformer also includes a central compensation capacitor coupled between a center tap of the secondary coil and ground, wherein the central compensation capacitor acts to suppress common-mode components in the differential signal. Next, the circuit uses a pseudo-differential amplifier to convert the differential signal into a single-ended output signal, which has double the frequency of the single-ended input signal.