3Department of Electronics and Communication
Engineering, NIT, Tiruchirapalli, Tamil Nadu
Abstract — The design of a compact notch monopole antenna for
application in ultra-wide band frequency domain is presented. The
enhanced impedance bandwidth of the proposed antenna and a preliminary
notch at 4.7 GHz are obtained by creating the square slot in the
circular radiating element, an open ended slot is also created in the
ground plane just below the microstrip feed-line and an open ended slit
ring in the thick protruded stub erected from the upper portion of the
square slot in the circular radiating element. The tuning of the notch
frequency of 5.5 GHz in the WLAN band of 5-6 GHz as well as the further
enhancement of notch is obtained by embedding a split ring resonator
(SRR) in the left side of the microstrip feed line. The proposed UWB
notch antenna provides the impedance bandwidth of 3.097GHz to 13.326 GHz
(fractional bandwidth of 125%). The average measured gain of the
proposed antenna is 7.1 dBi which covers the entire UWB band of
operation except the notch band of WLAN. The group delay is consistent
at around 0.2ns in whole of the UWB operating system except at the WLAN
band where the measured group delay is around 2.8ns. The proposed UWB
notch antenna exhibits consistent and stable radiation pattern. The
equivalent circuit for the proposed UWB notch antenna is developed. Time
domain performance of the proposed antenna is also examined from which
it is clear that the proposed antenna is highly capable of handling the
UWB short pulses in the UWB band of operation. Due to these novel
characteristics of the proposed compact UWB notch antenna, it can
effectively coexist with WLAN system and will find enormous application
in the future wireless communication system.
Index Terms —monopole, ultra
wideband, SRR, slot, slit ring, micro strip, time domain, Fidelity
factor.