Design Of Waveguide Slot Array Antenna At K-Band

Waveguide slot antenna is a kind of aperture antenna which is carved gaps on one side of the waveguide to make electromagnetic energy transmit into the out space through the gaps. There are lots of characteristics of this kind of antenna, such as diameters which is easier to be controlled, low side lobes, miniaturization, the shape which is easier to fix with the carrier. Due to these, the waveguide slot antenna has been widely used in military and civil products, especially has some advantages which can not be replaced by other types of antenna in the area of automotive radar application.In this paper a waveguide slot array antenna at K-band which can be used into the radar for car anti-collision has been designed. First part of the paper makes a exposition of the research significance of the waveguide slot antenna in 24GHz which is applied in automotive radar, and analyzes the research situation and development of the waveguide slot antenna both at home and abroad. The basic theory of waveguide slot antenna has been introduced with the Babinet’s Principle as basic knowledge, the equivalent circuits of the antenna are analyzed and calculated, the different forms of slot and two forms to be arrayed like travelling wave and standing wave are summarized. The three method of aperture distribution has been discussed and The Taylor synthesis theory has been introduced mainly and compared with other methods.Then the overall design scheme of antenna has been chosen according to the design index. Each aperture distribution has been created as the weight of current by Taylor synthesis. The model in computer of waveguide slot unit and a line slot array antenna which has 18 units has been built by using the simulation software HFSS and fed by coaxial-waveguide switch. And the result such as radiation pattern, the value of return loss and so on has been analyzed. Then the design of waveguide slot antenna which has been built by software has been machined into entity. At last the results of radiation pattern, the value of return loss and so on have been tested and basically meet the design requirements while the error of test result has been analyzed.