Frequency-Scanning Dual-Beam Parallel-Plate Waveguide Continuous Transverse Stub Antenna Array With Sidelobe Suppression

A novel parallel-plate waveguide continuous transverse stub (PPWCTS) antenna array with dual-beam, frequency-scanning, and low-sidelobe-level performances is proposed. Two identical H-plane sectoral horns with dielectric lenses are designed to feed the array at both ends of the PPWCTS alternatively. In order to make the two beams identical except for the beam direction, the symmetrical structure of the array is utilized. Through an optimal design, by feeding the array from the left, the gain of 17.5-20.8 dBi and the beam pointing angles from -23° to 2° have been achieved in the frequency-scanning range of 12.5-16 GHz, respectively. The radiation efficiency is 72.7% and the corresponding sidelobe level is suppressed to -18.4 dB by optimizing the leakage constants at the center frequency of 14 GHz. A good agreement has been observed between simulated results and measured ones.