In mobile radio geolocation and communications systems, it is often desired to know the angles of arrival of the direct path and multipath components of a received signal. For many reasons, traditional arrays with half-wavelength spacing are difficult to install at base stations.
Smaller arrays suffer from loss of resolution and increased mutual coupling.
But the problem is not impossible, if both electromagnetic and signal processing issues are considered. The effects of mutual coupling and calibration errors are taken into account. The ESL has an ongoing project to analyze, simulate, design, build and demonstrate this technology.