On-The-Aperture Patch Tuning (OTAPT) for Broadband Antennas

Dynetics proposes the use of On-The-Aperture Patch Tuning (OTAPT) as a potential solution for broadband performance from a low profile antenna. This solution is based on the innovative concept of integration of digital switching of tuning elements directly on the aperture surface. A single patch antenna can then be digitally tuned to successively lower frequencies, modifying the patch dimensions to the new resonant dimension by adding small strips. This technology may, in principle, be used over extremely broad frequency ranges, limited only by the performance of the switching devices employed in the aperture. RF power requirements on the switching devices (PIN diodes or GaAs switches, for example) are low relative to both the total radiated power because the incident RF power is distributed over several devices. The switching devices are readily controllable by digital computer commands which could be incorporated into existing crew instrumentation. With appropriate dual (or asymmetric) feed this concept can support any required polarization, including dual- or variable- polarization.