Wide Angle Scanning Circularly Polarized Leaky-Wave Slotted Ellipse-Patch Array with Flat Gain

A spoof surface plasmon polaritons (SSPPs) fed leaky-wave ellipse patch array with circularly polarized (CP) radiation, broad angle scanning and flat gain is illustrated in this paper. To generate CP waves, both the amplitude and 90deg-difference phase conditions need to be realized simultaneously. For the amplitude condition, two proximal coupling mechanisms are employed at the same time. The magnetic-couplings and electric-couplings make the patch array radiate a horizontally-polarized and vertically-polarized wave, respectively. With the help of optimized eccentricity e and the rotated cross-slot on every patch, a wide band 90° phase difference is obtained. As a result, a wide angle scanning CP LWA is presented. The pen-beam direction shift continuously from left to right with flat gain (gain variation less than 0.8 dB). In the operating band, the ARs at beam directions are less than 3 dB, which scan from -27° to +32°.