Broadband impedance matching network using low-pass type broadband matching, second harmonic reflection phase shifting and high pass complex conjugate matching in combination

Abstract

The operative bandwidth of a broadband RF amplifier (M1) is improved by using a low-pass type broadband impedance transformer (LPMN), instead of a broadband matching network, in a multi-stage impedance matching network connected, e.g., to the amplifier input, the output, or both. The multi-stage impedance matching network comprises three stages connected in series. The first stage is a low- pass type broadband impedance transformer (LPMN, LPMN1) that provides broadband low reflection fundamental impedances and high reflection for the second harmonics. The second stage is a phase shifter that controls the location of the second harmonic reflection coefficient phases. The third stage is a high-pass input matching circuit (MN, MN1) that transforms the complex conjugate device input impedance to a real impedance. The three-stage impedance matching network provides the fundamental and harmonic frequency impedances for broadband operations, as well as controllability of the second harmonic reflection coefficient phases where the device performances are consistent across the intended bandwidth..

Description

[0001] related application [0002] This application is a continuation of U.S. Patent Application Serial No. 16 / 193,884, filed November 16, 2018, the entire disclosure of which is incorporated herein by reference. technical field [0003] This invention relates generally to radio frequency (RF) circuits, and more particularly to low-pass wideband impedance matching circuits for wideband RF amplifiers. Background technique [0004] Radio frequency (RF) power amplifiers are an important part of wireless communication circuits. High power RF amplifiers are especially important in wireless communication networks, such as, for example, base stations providing wireless transmissions over large geographical areas. In order to transmit greater volumes and types of content (eg, video), wireless communications operate over wider and wider frequency bands. [0005] Broadband power amplifiers have received much attention in this regard. Wideband power amplifiers can support high data...

AI Technical Summary

Problems solved by technology

[0006] The impedance matching network is frequency selective and introduces impedance dispersion with respect to frequency, resulting in band-limited power amplifier operation

Also, the harmonic impedance presented to the device significantly affects device performance, and dispersion can lead to performance degradation at certain frequency ranges

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