Research And Design On Broadband Antenna And Filtering Antenna

Coincident with the increasing development of information and electronic technology, antennadesign has to satisfy the requirements of miniaturization, broadband and multi-function accordingly,as a result, research on broadband antenna and filtering antenna is of vital importance. Based on theRF simulation system’s demands on antenna elements, we firstly study and design the broadbandconical horn antenna, then based on the aforementioned design, we carry out research on bothwaveguide based and microstrip based filtering antennas.The main contribution and innovation of this dissertation are as follows.1. We study and design two dual-linear polarized quad-ridged horn antennas working within6~18GHz and2~18GHz band, respectively. We apply quadruple ridged waveguide and dual-port feedto realize broad working band and dual-polarization. To enhance the antennas’ performance, somecritical structures including ridged waveguide, matching block and the shape of the ridge areoptimized by using Ansoft High Frequency Structures Simulator. Finally, we fabricate the proposed6~18GHz ridged horn antenna and gain great agreements between the simulated and measured results.2. We study and design coaxial to waveguide adapter and then design a conical horn antennaworking within30~40GHz band. Finally, we fabricate both the proposed adapter and horn antenna,great agreements between the simulated and measured results are obtained.3. We study and design two waveguide based and SIW based filtering antennas workingwithin34~36GHz band. Based on the early designed Millimeter Wave antenna, we introduce a sixorder iris waveguide filter in the antenna feeding waveguide to obtain a filtering antenna workingwithin34~36GHz band. Then, considering that SIW structure not only shares traditional waveguides’advantages in high power and low loss but also with the normal plane printed transmission lines’advantages in easy fabrication and integration, we redesign the proposed filtering antenna using SIWstructure. The simulated results show that both designed filtering antennas exhibit good radiation andfiltering performance in working band.4. We research and design a microstrip based filtering antenna working within2.3~2.6GHzband. By treating antenna as the last resonator and load of bandpass filter, we conduct research onthe co-design method and apply it to design a filtering antenna working within2.3~2.6GHz band.Aiming at the problems of cumbersome calculations and too small conductor-to-conductor gap tofabricate in the design process, we put forward the corresponding solutions and redesign the filteringantenna with improved methods. Finally, we fabricate the proposed filtering antenna and compare themeasured results with the simulated ones. 5. We research and design three UWB band-notched antennas. We firstly discuss the UWBfiltering antenna co-design method and design a UWB band-notched antenna applying GeneticAlgorithm. Then aiming at the problems of slow convergence and vertex connection, we makeimprovements respectively and redesign two more UWB band-notched antennas. Finally we fabricateand test two of them. The measured results agree well with the simulated ones which verify thevalidity of our proposed method.