Low-profile wideband patch antenna with pattern diversity using custom-designed feeding schemes

摘要

A low-profile wideband patch antenna with pattern diversity is proposed in this paper. In our design, custom-designed feeding schemes are utilized to substitute for conventional power dividers beneath the ground plane, thus selectively generating the broadside or conical beam and introducing additional resonant modes. Then, by placing two novel feeding schemes orthogonally to realize pattern diversity, a new resonant mode is successfully excited, which fully makes use of the configuration of the two-port antenna. Moreover, for reallocating radiating modes, an array of four shorting pins is introduced to push up the resonant frequency of each first desired resonant mode, which enhances the overlapped impedance bandwidth. Finally, the proposed antenna is designed, fabricated, and measured. The measured results show that the antenna achieves a broad overlapped impedance bandwidth of around 28.5% ranging from 2.11 to 2.81 GHz. Meanwhile, the peak-measured gain is 7.0 dBi for the conical beam and 9.9 dBi for the broadside beam, while an isolation of 23 dB is also realized. Most importantly, novel feeding schemes still maintain the low-profile property of around 0.066 λ_0 (λ_0 is the free-space wavelength at 2.46 GHz).