Patent ID: 9473275
Filing Date: 2016-10-18
CPC Classification: H04B,H04L

Claim Text:
1. A gain asymmetry characterizing circuit for determining characteristics of gain asymmetry possessed by a transmitter, comprising: a baseband loopback path, coupled to a baseband node on a first transmission path of the transmitter; a test signal generating circuit, arranged to generate a first differential baseband test signal pair to the first transmission path, wherein the first differential baseband test signal pair includes a first baseband signal and a second baseband signal; during a first period, the first baseband signal and the second baseband signal are fed into a positive input node and a negative input node of the first transmission path, respectively; and during a second period, the second baseband signal and the first baseband signal are fed into the positive input node and the negative input node of the first transmission path, respectively; and a gain asymmetry measuring circuit, arranged to measure a response of a positive sideband of the gain asymmetry according to a first baseband loopback signal received from the baseband loopback path during one of the first period and the second period, and measure a response of a negative sideband of the gain asymmetry according to the first baseband loopback signal received from the baseband loopback path during the other of the first period and the second period.