A continual backward‐to‐forward beam scanning periodic microstrip leaky‐wave antenna with highly stable gain

Abstract

A limitation of the traditional periodic leaky‐wave antennas (P‐LWAs) is the existence of the open‐stopband (OSB) with the antenna gain greatly reduced at broadside. In this paper, a novel periodic microstrip LWA with highly stable gain is proposed and the OSB is eliminated, realizing continual backward‐to‐forward beam scanning. The unit cell of the proposed antenna consists of a transversal slot, a narrow transversal slot and two intersecting oblique slots, as well as a metallic via. By adding a narrow transversal slot and adjusting the inclination of the oblique slots, the antenna gain keeps stable while it is operating. A prototype is proposed and analyzed, achieving continual backward‐to‐forward main‐beam scanning from 8 to 10.2 GHz. The main‐beam scans from −35° to +30° with the maximum gain of 11.36 dBi, and the antenna gain of 11.05 dBi is obtained at broadside at 9.3 GHz with no significant degradation. The variation value of the gain is less than 0.66 dB while the main‐beam is scanning from −28° to +15° near the broadside, indicating that the antenna gain is highly stable.

Printed leaky‐wave antenna with stable gain and reduced cross polarization

“…Some linearly polarized leaky wave antennas are described in Kumar and colleagues. [12][13][14][15][16][17][18][19][20][21][22][23][24] But these antennas do not have sufficiently low cross polarization level. Thus, scope is there to design a LWA with stable gain and reduced cross polarization.…”

“…The cross polarization level of a linearly polarized antenna should be as low as possible. Some linearly polarized leaky wave antennas are described in Kumar and colleagues 12–24 . But these antennas do not have sufficiently low cross polarization level.…”

A miniaturized CRLH based SIW leaky‐wave antenna for continuous backward‐to‐forward fast beam scanning with low side lobe levels

“…An endfire to near broadside scanning SIW LWA is proposed in Ali and Khan, 19 but it has quite large dimensions. Recently, different types of LWAs are proposed such as scanning rate enhanced LWA, 20 circularly polarized LWA, 21 compact spoof surface plasmon polariton LWA, 22 wide beam scanning LWA, 23 periodic microstrip LWA with highly stable gain, 24 dual‐polarized dual‐band LWA, 25 asymmetric meander line slot‐based X‐band LWA, 26 and so forth. However, most of the reported structures either have a smaller beam scanning range or larger dimensions.…”