Nxp Usa, Inc.

Wenming Li

Yunfei Wang

Qi Wu

Tong Qiao

An amplifier includes a transistor, an input circuit coupled between an amplifier input and a transistor input terminal, and an output circuit coupled between a transistor output and a transistor output terminal. The input circuit includes an input-side harmonic termination circuit with a first inductor and a first capacitance in series between the transistor input terminal and ground. The output circuit includes a second inductor, an output-side harmonic termination circuit, and a shunt-L circuit. The second inductor is coupled between the transistor output terminal and the amplifier output. The output-side harmonic termination circuit includes a third inductor and a second capacitance in series between the amplifier output and ground. The shunt-L circuit includes a fourth inductor and a third capacitance connected in series between the amplifier output and ground. The input-side and output-side harmonic termination circuits resonate at a harmonic frequency of a fundamental frequency of operation of the amplifier.

Amplifiers and manufacture method thereof

An impedance-matching circuit includes a resonant circuit, first and second capacitors, and first through third inductive circuits. The resonant circuit includes a fourth inductive circuit connected in parallel with a capacitive circuit. The impedance-matching circuit receives a radio frequency power amplifier (RFPA) output signal, which includes first and second signals at first and second frequencies, respectively. A resonant frequency of the resonant circuit is between the first and second frequencies. The resonant circuit offers inductive and capacitive impedances to the first and second signals, respectively. The impedance-matching circuit generates a matched RFPA output signal including the first signal and the second signal, where the second signal is at a reduced voltage level.

Impedance-matching circuit

An output impedance-matching network for an RF power amplifier die includes a harmonic-prevention circuit that functions like a short circuit at a fundamental frequency of the amplifier and an open circuit at a second harmonic frequency of the amplifier. In certain implementations, the harmonic-prevention circuit has one or more parallel, reactive (LC) legs that resonate at the fundamental frequency and a parallel, reactive (capacitive) leg that causes the harmonic-prevention circuit to resonate at the second harmonic frequency. The harmonic-prevention circuit improves power transfer and efficiency of the RF power amplifier.

Growing community of inventors

Chengdu, China

Wenming Li