Smart antennas

A “classical” smart (adaptive) antenna array uses digital signal processing in conjuction with some algorithm to synthesize an antenna pattern according to some pre-determined specifications (e.g. null a jammer in a radar application, or track a user in a communications application). The DSP is typically extremely power hungry for signal bandwidths larger than audio. In our approach, some of the processing load is performed at the analog front end, reducing the load on the DSP circuitry. Alternatively, analog optical processing can be used to even further reduce the load on electronics and achieve functions for very high signal bandwidths (see “RF Photonics” below). We have shown that using a lens antenna array (multibeam array) the computational load for a variety of algorithms can be lowered. Simulation of a 121-element lens array:

(left) Image on the focal surface for an interfering signal at -30degrees off boresight in the far field (right) radiation pattern adapted to null an interference signal using a lens array and only 10 out of the 121 available elements. In a standard adaptive array, all 121 elements are equally important and have to be adapted. The desired signal is at +30 degrees.

Current work: Collaboration with the Technical University Munich, Germany, on direction of arrival arrays with quasi-optical front ends (with Prof. Peter Russer and Tuan Do Hong)