Experimental study of a microstrip patch antenna with an L-shaped probe

TLDR

The L‑shaped probe is an attractive feed for thick microstrip antennas, typically about 10 % of the operating wavelength. The authors propose a two‑element array fed by L‑probes. They conduct a parametric study of a rectangular patch antenna and design the two‑element L‑probe array. The single‑patch antenna attains a 36 % impedance bandwidth and ~7 dBi average gain, while the array suppresses cross‑polarization, preserves stable radiation patterns across the passband, and its resonant frequencies agree with predictions with minimal probe influence.

Abstract

The L-shaped probe is shown to be an attractive feed for the thick microstrip antenna (thickness around 10% of the operating wavelength). A parametric study on the rectangular patch antenna is presented. It is found that the antenna attains 36% impedance bandwidth (SWR/spl les/2) as well as gain bandwidth and about 7-dBi average gain. A two-element array fed by L-probes is also proposed. Experiments show that the array design can substantially suppress the cross polarization of the proposed antenna. Both the antennas have stable radiation patterns across the passband. Moreover, the measured resonant frequencies of the proposed antenna agree well with an existing formula and the L-probe does not have much effect on the resonant frequency.