Harmonic trap circuit for linear differential power amplifiers

A differential power amplifier comprising:

• one or more differential power amplifier stages configured to amplify an input signal and provide a differential output signal;
• and
• tank circuitry coupled to first and second output terminals of the differential power amplifier comprising:
• first trap circuitry coupled to a first output terminal of the differential power amplifier and second trap circuitry coupled to a second output terminal of the differential power amplifier, wherein each of the first trap circuitry and the second trap circuitry form a substantially low impedance path to ground about one or more harmonic frequencies of a differential signal provided by the differential power amplifier;
• and
• a tank inductor coupled between the first output terminal and the second output terminal of the differential power amplifier, wherein the tank inductor, the first trap circuitry, and the second trap circuitry form a substantially high impedance path to ground about a fundamental frequency of the differential signal.

A radio frequency transmitter comprising:

• a modulator configured to modulate a carrier signal at a desired transmit frequency to produce a modulated carrier signal;
• differential power amplifier circuitry coupled to an output of the modulator and adapted to amplify the modulated carrier signal to a level appropriate for transmission to produce an amplified and modulated carrier signal;
• tank circuitry coupled to first and second output terminals of the differential power amplifier adapted to process the amplified and modulated carrier signal to produce a processed carrier signal, wherein the tank circuitry comprises:
• first trap circuitry coupled to a first output terminal of the differential power amplifier and second trap circuitry coupled to a second output terminal of the differential power amplifier, wherein each of the first trap circuitry and the second trap circuitry form a substantially low impedance path from each of the first and second output terminals of the differential power amplifier to ground about one or more harmonic frequencies of a differential signal provided by the differential power amplifier;
• a tank inductor coupled between the first output terminal and the second output terminal of the differential power amplifier, wherein the tank inductor, the first trap circuitry, and the second trap circuitry form a substantially high impedance path to ground about a fundamental frequency of the differential signal;
• and
• an antenna configured to transmit the processed carrier signal.