Multi-frequency self-calibration of antenna arrays

Self-calibration techniques typically use signals collected in a single channel. To operate properly they require multiple co-channel signals to be present. Here we develop a self-calibration technique which uses data collected simultaneously from multiple frequency channels to calibrate the array and provide direction estimates for the signals in the channel of interest. The probability that a sufficient number of signals are present at any given time is dramatically increased when multiple channels are being used. This increases significantly the usefulness of self-calibration in practical direction finding scenarios. The performance advantages of multi-frequency calibration are illustrated by numerical examples.