Multi-band Phased Array Antenna Technology for global communication systems (Surprises and Opportunities)

The multi-functional, wide-band phased array antenna systems operating at multi-band frequency ranges (from 8 to 40 GHz) without the need for switching or reconfiguration are desirable for high volume data transfer in a timely manner. The multi-beam phasedarray antennas in a communication network (on the air-platform) will allow instantaneous communication links with the ground stations and with other airborne systems. The conventional approach for connecting the antennas in a network with the RF signalsgenerated in the terminal equipment uses wave-guides or coaxial cables. The mechanical configuration of wave-guides and their transmission characteristics at microwave/millimeter-wave operating frequencies restrict their usefulness in the multi-bandantenna systems. This proposal circumvents the problem by an innovative T/R module design (for phased array antennas) in which multi-band transmit RF signals are generated within the T/R modules. Low cost beam scan techniques are also described. Suchmulti-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 communication between the airbornesystems, surveillance, planar active arrays, sensors.