Increasing Bandwidth of Log Periodic Array Microstrip Antenna Using Parasitic Air Gap for Digital Video Broadcasting Application

Abstract

This paper proposes a new design of a log periodic array microstrip antenna with parasitic air gap for Digital Video Broadcasting application with return loss value of ≤-10 dB and $\mathbf{VSWR} \leq 2$ at working frequency of 478 to 694 MHz. The proposed antenna consists of two layers of substrate where at the bottom layer is a log periodic microstrip antenna and at the top layer is a parasitic load separated by air gap. The bandwidth of the design antenna can be optimized by adjusting the distance of air gap between the top and bottom layers of the proposed antenna. From the simulation results can be obtained the distance gap (d) is 2 mm with the bandwidth of the antenna design is 339 MHz (421 MHz to 757 MHz). Using parasitic air gap the bandwidth of the proposed antenna can be increased until 31.49% compared to the conventional periodic log antennas.