Effective Approach to Reduce Variation of Quasi-E-Plane Beamwidth of EH1-Mode Microstrip Leaky-Wave Antennas

• Published in: IEEE antennas and wireless propagation letters 2018-09, Vol.17 (9), p.1732-1735
• Main Authors: Xie, Danpeng, Zhu, Lei
• Format: Article
• Language: English
• Subjects: Antenna radiation patterns; Apertures; Computer simulation; Constant beamwidth; Cutoff frequency; Equivalence; Feature extraction; Leaky wave antennas; Leaky waves; Mathematical models; Microstrip antennas; microstrip leaky-wave antenna (MLWA); Model accuracy; pin-loaded technique; quasi-E plane; Strips; Tuning
• ISSN: 1536-1225; 1548-5757
• DOI: 10.1109/LAWP.2018.2864962

This letter presents an effective approach to reduce the quasi-E-plane beamwidth variation of EH1-mode microstrip leaky-wave antennas (MLWAs) as main beam scans from broadside to endfire. Theoretical equivalent modeling of quasi-E-plane radiation patterns of EH1-mode MLWAs is developed first, which intrinsically figures out two key factors that could effectively ameliorate the lateral beamwidth variation, i.e., enlarged strip width and increased operating frequency. Then, the unique pin-loaded technique is employed to realize of the above requisites, and full-wave numerical extraction is conducted to thoroughly reveal the pin-loaded features of flexibly enlarged lateral strip width. One set of analyzed parameters are selected for implementation of the proposed pin-loaded EH 1-mode MLWAs. And, a differentially driven antenna prototype is finally designed, fabricated, and tested. Both simulated and measured half-power beamwidths are in good accordance with the theoretical one, not only verifying the accuracy of the equivalent modeling but also validating our proposed approach to suppress the beamwidth variation during beam scanning.