Quadrature Mixer LO Leakage Suppression Through Quadrature DC Bias

BALDWIN, JESSE G ; DUBBERT, DALE F.

Sandia National Laboratories

关键词: Data Analysis;    Amplitudes;    Wave Forms;    Oscillators;    Radar;   

DOI  :  10.2172/800958
RP-ID  :  SAND2002-1316
RP-ID  :  AC04-94AL85000
RP-ID  :  800958

美国|英语

来源: UNT Digital Library

【 摘 要 】

A new concept has been developed which allows direct-to-RF conversion of digitally synthesized waveforms. The concept named Quadrature Error Corrected Digital Waveform Synthesis (QECDWS) employs quadrature amplitude and phase predistortion to the complex waveform to reduce the undesirable quadrature image. Another undesirable product of QECDWS-based RF conversion is the Local Oscillator (LO) leakage through the quadrature upconverter (mixer). A common technique for reducing this LO leakage is to apply a quadrature bias to the mixer I and Q inputs. This report analyzes this technique through theory, lab measurement, and data analysis for a candidate quadrature mixer for Synthetic Aperture Radar (SAR) applications.