On the design of compact broadband gap-coupled microstrip patch antenna with PBG

This paper presents the design of compact broadband gap-coupled microstrip antenna with photonic band gap. The single patch microstrip antenna and gap-coupled microstrip antenna have been designed and fabricated on ε_F = 2.2 with 1.588 mm substrate thickness. The gap-coupled microstrip antenna consists the number of parasitic elements which are gap-coupled to driven patch. The measured center frequency of the gap-coupled and patch antenna is 2.568 GHz and 2.483 GHz respectively. The impedance bandwidth of gap-coupled antenna has been observed 4 times greater than microstrip patch antenna at VSWR 2:1. The photonic band gap (PBG) has been applied to suppress the surface wave propagating on substrate which improves the radiation pattern and bandwidth.