A design approach to miniaturized, dual-resonant microstrip circular sector patch antenna with tilted circularly polarized (CP) beam is proposed. As mathematically laid down at first, the range of an asymmetric multiresonant prototype dipole’s length should be set as the positive odd-integer multiples of one-quarter wavelength, such that the resonant frequency could be accordingly reduced by one-half to the symmetric case. In this way, an asymmetric circular sector patch radiator can then be employed to realize a unique tilted CP beam by simultaneously exciting two orthogonal, odd-order resonant modes via proper perturbations. As numerically and experimentally validated, dual-resonant microstrip antennas with compact patch, flared angles of 330°/270°, impedance bandwidth of 26.6%/35.8%, and tilted CP 3 dB axial ratio (AR) bandwidth of 7.3%/12.0% can be realized on single-layered, air substrate with a height no more than 0.07 wavelength. It is evidently verified that the proposed approach should be effective for reducing patch size, enhancing impedance bandwidth and realizing tilted CP beam without increasing antenna profile, inquiring multiple radiators or employing reactance compensation techniques.

中文翻译：

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宽带双模谐振下具有小型化扇形贴片的倾斜圆极化波束微带天线

提出了一种具有倾斜圆极化（CP）波束的小型化双谐振微带圆扇形贴片天线的设计方法。正如最初的数学规定，非对称多谐振原型偶极子长度的范围应设置为四分之一波长的正奇整数倍，这样谐振频率可以相应地降低到对称情况的二分之一。通过这种方式，然后可以使用不对称的圆形扇形贴片辐射器通过适当的扰动同时激发两个正交的奇数阶谐振模式来实现独特的倾斜 CP 光束。经数值和实验验证，双谐振微带天线具有紧凑贴片、330°/270° 的张角、26.6%/35.8% 的阻抗带宽和 7.3%/12 的倾斜 CP 3 dB 轴比 (AR) 带宽。在高度不超过0.07波长的单层空气基板上可以实现0%。显然，所提出的方法对于减小贴片尺寸、提高阻抗带宽和实现倾斜 CP 波束是有效的，而无需增加天线剖面、查询多个辐射器或采用电抗补偿技术。