Optically controlled scanning antennas comprising a plasma grating

The mainstream developers of electronically or photonically controlled steering antennas employ phased array architectures (PAA) which suffer from high cost and therefore have limited applications. The main challenge is to reduce the cost of the key parts of phased arrays, the phase shifters or the true time delay elements. On that score, the desired progress has not yet been achieved. However, photonically controlled scanning can be achieved even without using the above mentioned discrete elements. We present two novel architectures for millimeter wave (MMW) scanning antennas controlled by light. They are based on the interaction of MMW, with photonically created electron-hole plasma in a semiconductor medium and are thus radically different from PAAs. The new antennas are expected to be much more cost effective than phased array antennas.