A Low-Profile Patch Antenna With Monopole-Like Radiation Patterns

In this paper, the TM22 mode of a square patch antenna is excited to generate a monopole-like radiation pattern. The square patch antenna is centrally fed by a coaxial probe, where four shorting pins are rigorously arranged around the feeding point to obtain good impedance match for the antenna. The simulated results demonstrate that the proposed antenna has an impedance bandwidth from 5.73 to 5.91 GHz with a total profile of 0.02λ (λ is the wavelength at 5.8 GHz), the maximal radiation direction is pointing to θ=27o, the gain and radiation patterns within the impedance bandwidth are all about 5.0dBi and monopole-like, respectively. The measured results are consistent with that of simulation.