The Unexpected Challenge of Baseband I/Q Imbalance Compensation
Tactical Electronic Warfare Division, NRL
Date: Wednesday, December 02, 2015
Time: 6:30 Reception and Dinner (Optional), Lecture 7:00
Place: TeqCorner, 1616 Anderson Road, McLean, Virginia, 22102
All IEEE members and guests are welcome to attend.
Cost: Lecture and reception free, optional Dinner $10
Please RSVP (Dinner only) to Roger Kaul,
firstname.lastname@example.org by November 30th
Direct conversion zero-and-low-IF radios are often an attractive architectural consideration, with advantages such as lower cost, reduced power, fewer components, and smaller size. However, imbalances between the in-phase (I) and quadrature (Q) channels result in unwanted distortions. Therefore, compensating for I/Q imbalances is immensely valuable in eliminating one of the significant issues plaguing analog components in radio frequency (RF) transmitters and receivers.
There are a number of papers that quantitatively describe algorithms to digitally mitigate I/Q imbalance. However, none of these papers describe the physical phenomenology that fundamentally limits digital I/Q compensation regardless of the signal processing being used. In this talk we quantitatively present the reason for the limited impact linear and nonlinear digital compensation has on I/Q imbalance, from both an RF/IF device and signal processing standpoint, and describe a technique to identify when baseband I/Q compensation will be adversely affected due to the RF/IF architecture of the front-end analog components.