Wideband Circularly Polarized Split Patch Antenna Loaded With Suspended Rods

A novel single-fed wideband circularly polarized (CP) split patch antenna with two suspended metal rods is proposed in this letter. The proposed antenna has two semi-circular patches with a suspended metal rod loaded on each patch. The antenna is fed by a coupling slot and a hammer-headed microstrip line on the opposite side. Two inclined semicircular patches are combined with slot to form a CP radiation at low-frequencies band; furthermore, two suspended metal columns form a loop-type antenna at high-frequency band, which are combined with the slot forming another CP resonance point. The combination of these two CP resonance points broadens the CP bandwidth which is indicated by the AR curve. The proposed antenna has a simulated 3 dB AR bandwidth of 22.58% (4.87-6.11 GHz) and a wide -10 dB impedance bandwidth of 48.75% (3.8-6.25 GHz). The overall electrical size of the antenna including the ground is 0.46 × 0.46 × 0.154 λ0
³
(with λ0 being the free-space wavelength at 5 GHz). The measured peak gain of the antenna is greater than 8 dBic from 5 to 6 GHz. A 2 × 2 antenna array based on the proposed antenna element is also implemented and experimentally verified. The 2 × 2 array has a 3 dB AR bandwidth of 49.7% (4.02-6.68 GHz). This proposed antenna and its array exhibit a very novel structure and an interesting working principle while demonstrating excellent CP radiation performance. They could be applied in various 5G or other communication systems, which require CP radiation.