Miniaturized Reconfigurable Multiband Antenna For Multiradio Wireless Communication

This paper introduces a general methodical approach for designing frequency reconfigurable antennas. This method was successfully used to design a novel coplanar waveguide (CPW)-fed slot frequency reconfigurable antenna capable of operating at four preselected frequency bands distributed over a wide frequency range from ~ 59.5 MHz to ~ 1000 MHz (i.e., ~ 4 octaves of bandwidth) while keeping its overall size as small as possible. To add reconfigurablility to the antenna, optimally-designed and electronically-controllable PIN diode-loaded slots were used to strategically manipulate the flow of current path and consequently change the characteristics of the antenna. Designing for the lowest operating frequency (59.5 MHz), capacitor-loaded meandered slot lines and reconfigurable matching network were implemented to keep the size of the antenna as small as possible. The resulting overall size of the antenna is only 0.06λL×0.06λL where λL is calculated at 59.5 MHz. The measurement results verified that the antenna successfully operates at 59.25-59.75 MHz, 314-398 MHz, 430-496 MHz, and 792-950 MHz, all with an almost omnidirectional pattern and an acceptable gain.