Open AccessDiode‐based IQ imbalance estimation in direct conversion transmitters
Author(s) -
Li Wei,
Zhang Yue,
Wang Jin,
Huang Like,
Xiong Jian,
Maple Carster
Publication year - 2014
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2013.3819
Subject(s) - transmitter , electronic engineering , diode , computer science , broadband , signal (programming language) , wireless , quadrature (astronomy) , telecommunications , electrical engineering , engineering , channel (broadcasting) , programming language
Direct conversion transmitters are widely used in wireless systems for their inherent features of being simple and low cost. In this architecture, the inphase ( I branch) and quadrature signal ( Q branch) will be unconverted to the RF frequency band by quadrature modulation. However, the drawback of the direct conversion architecture is that it is sensitive to IQ imbalance caused by the impairment of analogue devices in I and Q branches. It then results in interferences in mirror frequencies which degrades the signal quality. Therefore, the accurate measurement of IQ imbalance is crucial. A diode‐based method to measure the broadband IQ imbalance is proposed which does not need additional measurement instruments. Measurement results show the effectiveness of this method.