Design And Simulation Of Frequency Scanning Antenna Array

Antenna is used as a key part of wireless communication, radar, navigation and manyother applications. Its performance directly affects the overall system’s function. Theproperties of frequency scanning antenna, such as it’s simple structure, low profile, low costand light weight array, makes it suitable for use in portable systems.However, there also exist some shortcomings for frequency scanning array. For instance,its side-lobe is not easy to control, narrow frequency scanning angle and the azimuth angleof the main beam is too broad.To overcome these drawbacks, this article describes the designs of two frequencyscanning arrays with low side-lobe and wide scanning angle. The first is a slotted waveguideantenna array; the other is a rectangular microstrip array that is fed by slow-wave structureformed by rectangular waveguide. The performance of these two frequency scanning arrayswere simulated and analyzed. The outline of this paper is as follows:Based on the antenna array pattern synthesis method and the frequency scanning arraytheory, the design methodology of Dolph-Chebyshev and Taylor synthesis is described. Theadvantages and disadvantages of each design methodology is then compared. The designmethod of Frequency scanning array parameters is also elucidated.Using the Taylor pattern synthesis method, we designed22element slotted waveguideantenna array with-19dB side-lobe,20°beam scanning angle. In order to further enhancethe operating bandwidth of slotted waveguide, we increased the scanning angle using themethod of ridge addition for waveguide. A single ridge waveguide frequency scanning arraywith-15dB side-lobe,30°beam scanning angle and15°beam width was designed.To further reduce the side-lobe level, the width of the beam and increased the beamscanning angle. A rectangular waveguide formed structure of the slow-wave line was fed tothe rectangular microstrip antenna array for a low side-lobe and wide scanning anglefrequency scanning array. The described design gives rise to an azimuth plane beam width of10°or less, a maximum azimuth side-lobe below-17dB, and a beam scanning angle of45°.The performance of the designed antenna array was verified using three-dimensionalelectromagnetic field simulation software.