Patent ID: 9166680
Filing Date: 2015-10-20
Classification: H04B,H04L

Abstract:
1. An apparatus for measuring IQ imbalance, the apparatus comprising: a light generating unit generating optical and reference signals to provide the optical and reference signals to an optical receiver; a graph creating unit creating a Lissajous figure by using an in-phase (I) signal and a quadrature-phase (Q) signal output from the optical receiver in response to the optical and reference signals; and a calculating unit calculating IQ imbalance for the optical receiver referring to the Lissajous figure, wherein the light generating unit comprises: a light source generating a reference optical signal; an optical splitter splitting the reference optical signal into first and second optical signals and outputting the second optical signal as the reference signal; an optical phase modulator modulating a phase of the first optical signal in response to a control voltage, and outputting the modulated first optical signal as the optical signal; and a function generator controlling the optical phase modulator by using the control voltage.