A Compact Triple Band-Notched UWB Antenna Using Sinusoidal EBG

In this paper, a compact (17.7 mm x 12 mm) triple band-notched UWB antenna is presented. For inserting desirable notches, three concentric ring resonators have been placed on the back side of antenna in a manner that the first resonance frequency of each resonator coincides with one of the desired notches. Considering that the second resonance frequency of outer ring resonator places in UWB frequency band, an EBG using sinusoidal variation of the characteristic impedance of outer resonator is used to reject the spurious notch. CST simulation results verify good performance of the antenna and show acceptable frequency and time domain characteristics such as wide frequency band width (3 GHz - 10.3 GHz) with good return loss( greater than 17 dB in most parts of band), fairly deep notches, approximately omnidirectional patterns and low group delay variations.