Circularly polarized UWB antenna considering time domain characteristics

In this article, a reflector back ultra-wide band (UWB), circularly polarized (CP) antenna is presented using asymmetric circularly curved radiating elements. The circular aperture on the reflector plane is connected with the radiating plane using two shorting pins to maintain the impedance bandwidth and axial ratio (AR) bandwidth. In addition to the frequency domain, time domain performances are investigated to understand the receiving signal quality, considering the pulse spreading effects. The received signal quality is quantified for near field (NF) and far field (FF) with the parameter system fidelity factor (SFF). It is observed that the SFF becomes stable and less dispersive from the minimum distance 75 mm from the antenna at near field. The measurement result also shows that the proposed antenna can provide maximum 10.2 dBic peak gain, $ 78.9\% $ 78.9% of impedance bandwidth and $ 82.3\% $ 82.3% of axial ratio bandwidth with system fidelity factor (SFF) of 0.95 and 0.97 for NF and FF respectively. In addition to this, the variation of group delay is within 1.3 ns for NF and FF cases.