Anotace:
This paper designs a unidirectional high gain, low-cost cascading ring antenna with coaxial feeding and metal without the dielectric. The designed antenna suits for high power transfer applications such as Radar communications, wireless local area network (WLAN), and base stations. The use of gap-coupled cascading rings in the design enhances the gain to 13.4 dBi at the resonance frequency of 2.45 GHz, improving the side lobes level and front-to-back ratios. The proposed antenna has symmetrical half power beam width (HPBW) in H-plane and E-plane of 37 degree and 36.5 degree, respectively. The cross-polarization field component of the antenna is below -25 dB in H-plane, and below -45 dB in E-plane is obtained from the measurements. The measured antenna has 10 dB bandwidth of 95 MHz i.e., 2.405-2.50 GHz that covers the ISM 2.45 GHz band. The designed antenna is planar in structure with compact radiating rings of size 1.16λ×0.4λ×0.1λ. The measured and HFFS simulated results are found in good agreement.