RCS Reduction of High-Gain Microstrip Antenna Based on Slot-loaded TM30 Mode

This paper Presents a high-gain, low-profile, low-radar cross section (RCS) microstrip antenna using high-order modes TM30. The proposed antenna consists of a rectangular patch, which operates in high-order mode TM30, three slots etched in y direction, and four identical slots etched in x direction. A three-element equivalent magnetic current array is constructed within a single cavity, including two from the radiating aperture of the patch and another one from the etched slots on the patch. Only one feeding and one single-dielectric layer are required in the proposed antenna, which exhibiting low profile and simple feeding. The gain of the single-layered antenna is 10.7 dB, which is 2-3 dB higher than conventional microstrip antenna operating in the fundamental TM10 mode. The RCS is reduced more than 5 dB by the slots etched in x direction. The size of the antenna is 0.81 λ
0
×0.74λ
0
×0.029λ
0
(λ
0
is the free-space wavelength at the center frequency). The proposed antenna has the advantage of the high gain, low RCS, low profile, single feeding and low cost, with the great potential in conformal antennas and aerial vehicle.