Research On The Design Of Small Planar Slot Array Antenna

Waveguide slot array is a kind of antenna that it is slotted on the surface of wide wall or narrow wall of the waveguide. These slots can compose liner or planar arrays by appropriate arrangements to meet the various demands of application. With the good characteristics of high gain, controllable aperture distribution, compact structure and easy processing, waveguide slot arrays play an irreplaceable role in the application of radar antennas. The planar slot antenna, which is slotted in the wide wall of the waveguide, has been widely used because of the advantages of low loss, light weight, high power capacity, high polarization purity and high mechanical strength. It can be applied in fire-control radar, missile seeker and so on.The theories of planar slot antennas have been relatively completed. But for the concrete engineering design, there are curtain problems that need special treatments. In this paper, the planar slot antenna has been studied. And according to the specifications and the application based on the design theory and the general design process, the conductance value of the slot was got by the relationship between the equivalent conductance and excitation level in the transmission model of the waveguide slot. The length of all the slots was the same and a reflector was added to the radiating surface. This new method is applicable to liner arrays and planar arrays of minitype. And its feasibility has been proved by simulation data and experimental test results.The main contents of this paper are as follows:1. The paper analyzed the basic theory of antenna arrays and common methods of antenna synthesis. And it studied the theory of waveguide slot antenna as well as the principles of design and summarized the general design process of standing-wave array slotted in the wide wall of the rectangular waveguide.2. An 10×8 array operating at 9.5GHz has been designed in a practical engineering design with the assistance of electromagnetic simulation software which is based on numerical analysis.3. A miniaturized waveguide power divider has been designed as the feeding circuit of the waveguide planar slot array. The divider was formed by T-junction. And the volume of the whole network was limited by appropriate topology. The power allocation was adjusted by several inductive diaphragms so as to satisfy the determined feeding distribution.The test result showed that the experimental data of the planar slot antenna array has met the engineering application requirements. According to the results, further improvements were put forward to improve the performance of the antenna.