We propose a method to design compact circularly polarized (CP) antenna using a novel sunshine-shaped slotted radiating patch, which exhibits slow-wave and other interesting properties. The structured radiating patch introduces adjustable coupling between a pair of orthogonal modes (TM10 mode and TM01 mode) to facilitate good axial ratio and reflection parameters of the antenna simultaneously in the radiating frequency band. A π/2 balun is employed to excite the TM10 and TM01 modes by using back feeding structure. Based on the proposed method, a compact left-hand CP antenna is designed, fabricated, and measured to verify the feasibility of the design method. The whole antenna is 0.17λ0×0.17λ0 in dimension (λ0 is the wavelength in free space) and the measured maximum gain is 5dBic in the working band, and 3-dB axial ratio (AR) bandwidth is 0.4% for left-hand CP.
- Circularly polarized (CP) antenna
- patch antenna
- sunshine-shaped slotted patch
- sunshine-shaped slotted radiating patch
ASJC Scopus subject areas
- Electrical and Electronic Engineering