A 2-D Frequency Beam-Scanning Antenna Array Based on Varactor-Embedded Slow-Wave Phase-Shifter

A frequency beam-scanning antenna array capable to scan from -30° to +30° in azimuth plane and -35° to +35° in elevation plane is presented in this paper. In order to realize this unique function, two types of slow-wave phase-shifters are designed to provide phase progressions. In the azimuth plane, a hairpin filter loaded with meandering line is utilized as the phase-shifter. While in the elevation plane, an improved structure of the above filter with embedded varactors is implemented. In such a setup, phase progression along perpendicular directions are determined without interference, thus guarantee continuous scanning within a 2-D conical space. A prototype operating around 4.8GHz is synthesized in parts, and simulation results are given for validation.