Patent ID: 9054759
Filing Date: 2015-06-09
Classification: H03F,H04B

Abstract:
1. A VSWR measurement circuit comprising: a first directional coupler that extracts a partial main signal of main signals amplified by a power amplifier in order to transmit from an antenna; an analog/digital converter that converts the main signal extracted by the first directional coupler; a distortion compensation circuit that performs distortion compensation by using the signal converted by the analog/digital converter; a second directional coupler that is connected to an antenna terminal through a cable, and extracts a reflection signal included in feedback signals; a power measurement unit that performs power measurement of the main signal extracted by the first directional coupler and the reflection signal extracted by the second directional coupler, respectively, and measures a VSWR (Voltage Standing Wave Ratio); and a main signal component removing circuit that removes a main signal component included in the feedback signals to output to the power measurement unit, with a main signal taken out from a preceding stage of the distortion compensation circuit and signals in which the feedback signals are converted into digital signals by the analog/digital converter being set as inputs.