Reconfigurable Antenna With a Diversity Filtering Band Feature Utilizing Active Devices for Communication Systems

Presented in this article is a novel, reconfigurable UWB antenna with a diversity notched band. By switching the pin-diode and tuning the varactor to a certain location along the slot of the antenna, the selection of an operating filtering band is achieved. The antenna is constructed using a FR4 substrate with a thickness of 0.8 mm and having the ε_r value equal 4.4. The band-notch function is produced by inserting an inverted U slot on the radiating patch. Using two PIN-diodes in the slot of the radiation patch, the tunability of the created notch is possible by loading the slot with a lumped varactor. Using the embedded varactor, an electronically controlled notched band antenna is designed and fabricated including a single varactor diode with a varying capacitance value of 0.63-2.67 pf. Moreover, a notched band tunability of 2.7-7.2 GHz is obtained. In addition to the ON/OFF PIN-diodes, the switches yield a band filter which can be suppressed at any given moment.