Analysis of gap-coupled microstrip antenna

Abstract

In the present paper the analysis of a gap-coupled microstrip antenna (GCMSA) is carried out using the circuit concept and consequently various parameters such as input impedance, VSWR and return-loss are investigated for different air gap lengths. It is observed that the resonant frequency of the antenna with different substrates depends on the gap length. The gap-coupled antenna behaves as an RL network below the resonant frequency for all substrate materials and gap lengths, whereas the antenna behaviour above resonance is like an RC network. It is further observed that the resonant frequency of the GCMSA decreases with increasing gap length.