Research & Design Of Ridged Waveguide Slot Planar Array Antenna

Waveguide slot array antennas have the obvious characteristics of compact structure, light weight, high efficiency, power capacity, easy to achieve low side-lobe and ultra low side-lobe, so it was used widely in radar and communications fields. The ridged-waveguide slot array antennas have been given more attention because of the wide-band property.In this paper, a method for the design of the ridged-waveguide slot planar array antenna is studied. Begin with the technical specification, we discuss the key technique and the solutions in the antenna design. The radiation properties are analyzed and the feed system for the array antenna is designed. Finally, the beam broadening and scanning of a phased array antenna is studied through testing.The planar array antenna discussed in this paper needs to achieve a narrow beam width and low side-lobe on the horizontal, a shaped beam on the vertical. Firstly, the amplitude and phase of the level pattern are synthesized. Secondly, by combining the theory of waveguide slot array and the electromagnetic computing software, the radiation front of the antenna is designed. It meets the design requirements by comparing the results from the different software. The feed system is designed on the base of the amplitude and phase distribution of the shaped beam on the vertical. The ridged-waveguide quadrature hybrid coupler (coupling on narrow wall) is adopted for the feed system. Base on the theory of the waveguide quadrature hybrid coupler, the single ridged-waveguide quadrature hybrid coupler is designed and then connected to compose the ridged-waveguide power splitter.Finally, the beam controlling of the phased array antenna is tested and studied. After testing the amplitude and phase in the initial state, we achieved the beam broadening and scanning by using the program and the broadened phase optimized by the Genetic Algorithm. Comparing with the calculated data, the tested data meets the design requirements.