Software Defined Match Control Circuit Integrated With a Planar Inverted F Antenna

A planar inverted F antenna (PIFA) is integrated with a software-defined match control (SDMC) circuit in order to create an impedance match for a diverse set of frequency standards. The individual PIFA achieves better than 10 dB reflection coefficient for a 13.6% bandwidth at 2.45 GHz. The SDMC is a microstrip circuit with tuning diodes that are adjusted to tune the input impedance of the antenna and to select a targeted frequency range of operation. It is both an antenna impedance tuner and tunable filter. This paper discusses the design approach for the system and presents simulated and measured results. The results show that the combined antenna and SDMC can be tuned to operate at many worldwide frequency ranges even when the individual PIFA is not specifically matched to the frequencies.