Multi-band phased array antenna for airborne systems

The multi-channel, wide-band phased array antenna systems operating at a number of high microwave and millimeter-wave frequencies without the need for switching or reconfiguration are desirable for high volume data transfer in a timely manner. A number ofmulti-band phased array antennas in a network (on the air platform) will allow instantaneous communication link with the ground stations and with the other airborne systems. The conventional design approaches to phased array antenna generally result invery complex, expensive, narrow-band and less efficient systems because of high RF loss in the diplexer circuits needed at the antenna to isolate the transmit and receive frequencies. This proposal circumvents the problem by an innovative design approachin which the necessary isolation between the-transmit and receive frequencies is achieved partially by the field orientation between the-transmit and receive signals and partially by the low loss filters. The new approach will result in low loss diplexerdesign thus providing more efficient antenna system design in terms of high EIRP and low receiver noise figure. The system noise figure is expected to be 2 to 4 dB lower than the conventional design at (Ka-band). Low cost beam scan techniques are alsodescribed. Such multi-band phased array antenna design will significantly enhance the system flexibility for air platforms. The proposed research will have a far-reaching impact on future high data rate communication systems, cross link communicationbetween the airborne systems, surveillance, planar active arrays, and sensors.