A very wideband antenna with dynamically-controllable band rejection

A very wideband slot antenna with reconfigurable stopband is presented. The reconfiguration is achieved by modifying the effective length of an embedded stopbandresonator by means of three pairs of PIN diodes. Four different operative states—three of them with a stopband notch and one with the full antenna bandwidth matched—are achieved depending on which PIN diodes pair is forward biased. The CPW-fed antenna is designed for an input impedance of 50 Ohms to avoid the use of a matching network. Its operability is demonstrated based on the measurement of a fully functional reconfigurable implementation in the 1.5-10 GHz band.