Provided is a pulse modulation circuit that improves the on/off operation and improves the on/off ratio of an output power of the entire pulse modulation circuit in the switching operation. The pulse modulation circuit inputs a local oscillation wave and a DC pulse signal, mixes a second harmonic wave...http://www.google.com/patents/US7327991?utm_source=gb-gplus-sharePatent US7327991 - Pulse modulation circuit
