Circularly Polarized Ka-Band High-Gain Antenna Using Printed Ridge Gap Waveguide and 3-D-Printing Technology

A low-cost high-gain circularly polarized antenna is proposed, the proposed antenna achieves a gain of 20 dBi and an axial ratio bandwidth of 6.5%. The proposed antenna is extremely low in cost as it uses printed ridge gap waveguide (PRGW) technology. The use of PRGW technology suppresses the parasitic and back-lobe radiation from the feed, which maintains neat radiation characteristics for the radiating antenna. The structure is made of a magnetoelectric (ME) dipole, which illuminates a set of adjacent dielectric slabs. The diffracted fields from the edges of the dielectric slabs add up constructively with the ME dipole radiated fields in the boresight and boost the gain of the ME dipole. Accordingly, the antenna structure relaxes the need for designing a feeding network by utilizing the diffracted fields from dielectric slabs edges. A 3-D-printed dielectric polarizer is used to further boost the gain and transform the polarization of the antenna to circular polarization. The antenna possesses a focused pencil-beam pattern that is well-suited for several millimeter-wave (mm-wave) applications.