Ai-Zhong Wang

A conformal circularly polarized H-plane horn antenna with broadband and low-profile characteristics is proposed in this paper, which is integrated with quasi-Yagi and wrapped around a hollow cylinder. The H-plane horn based on bent corrugated substrate integrated waveguide (BCSIW) technology and the quasi-Yagi with fan-shaped driving elements provide the vertical and horizontal linear polarized waves respectively, which generates circularly polarized radiation combining with the suitable phase delay provided by the transition section. The proposed antenna is wrapped around a hollow metallic cylinder with radius of 100 mm and height of 90 mm. The measured voltage standing wave ratio (VSWR) of the fabricated antenna is less than 2.0 in the frequency range over 9.4 GHz (81%) while the axial ratio (AR) is below 3 dB from 9.4 GHz to 21.7 GHz (78%). The antenna also exhibits stable radiation pattern with peak gain of 12.1 dBi and a cross-polarization below -17dB over the whole frequency range. It is observed that the measured results agree well with simulated ones.

A W-band H-plane horn array antenna with tilted radiation beam based on waveguide structure is proposed in this paper. The designed antenna array consists of four H-plane antenna elements and a broadband feed network. The distribution of excitations is determined by the theory of maximum power transmission efficiency (MMPTE). A multiple branch coupler, two T-junctions and three fixed phase shifters are employed to construct the feed network, which can generate the required amplitude and phase in broadband frequency range from 80 GHz to 100 GHz. The computer numerical control (CNC) milling machines technology is employed to machine the feed network and antenna. All measured and simulated results are in good agreement, which verify the feasibility of the theory of MMPTE to generate a radiation beam directed to any angle from −35° to 35° with suitable excitation provided by the proposed feed network in this paper.