Research On Grating Waveguide Slot Array Antenna

Filtering antennas are the antennas which possess the filtering performance.They are the integration of the antennas and filters,both of which are important components in the RF front-end of the wireless communication system,and meet the system's miniaturization requirement in the near future.At present,there are generally two methods in the filtering antenna design.The first method is cascading the antenna and the filter in a single module.This method connects the antenna and the filter directly and eliminates the use of typical 50/75 ohm connecting transmission line,so that the connection efficiency is enhanced and the total size is saved.The section method is merging the antenna and the filtering structure together,which means integrating the filtering structure into the antenna or the feed network.Compared with the first method,the section method realizes a true fusion of the antenna and filter.Waveguide slot array antenna is an antenna form which has high efficiency,power capacity and polarization purity.It is widely used in radar system,satellite communication system and so on.Waveguide transmission line is a low-pass structure whose interior is hollow.This makes it a good candidate for internal filter design.Therefore,we proposed a new method which merges the frequency-selective grating waveguide structure into the waveguide slot array antenna to realize the filtering antenna design.Firstly,this paper illustrates the basic principles of the waveguide slot array antenna.By using the circuit analysis method and the field analysis method,we calculate the transmission properties of the rectangular grating waveguide and explain its frequency selectivity.Moreover,by conducting simple parametric analysis,we discuss the generation of stopband of the rectangular grating waveguide.Meanwhile,we expound the reason why it is suitable for slot array antenna design.Secondly,targeted at the receiving band of the Ku-band terrestrial satellite communication system,we utilize the frequency-selective rectangular grating waveguide structure to design a rectangular grating waveguide slot array receiving antenna.The proposed antenna can effectively receive the signals from the receiving band,but suppresses the interference from the transmitting band.An eight-slot rectangular grating waveguide slot linear array antenna is simulated,designed,fabricated and measured.The results show that compared with the traditional waveguide slot array antenna,the proposed antenna performs the normal antenna gain in the receiving frequencies but the lower antenna gain in the transmitting frequencies,which confirms its filtering performance as the satellite communication receiving antenna.Thirdly,targeted at the wide-angle scanning requirement of the Ku-band terrestrial satellite communication system,we propose a grating ridged waveguide slot array antenna.The antenna is based on the high-polarization-purity ridged waveguide V-shaped slot array antenna.By merging the frequency-selective grating ridged waveguide structure into the antenna,the frequency-selective radiation function is realized.An eight-slot grating ridged waveguide slot linear array antenna is simulated,designed,fabricated and measured.The results show that the proposed antenna performs the normal antenna gain in the receiving frequencies but the lower antenna gain in the transmitting frequencies,which confirms its filtering performance as the satellite communication receiving antenna.Finally,we summarize the contents of the whole paper and illustrate the outlook of our work.