Ku-band Waveguide Generalized Cut Chebyshev Filter Developed

With the rapid development of modern microwave communication techniques, the spectrum is becoming more and more precious, the frequency spaces become narrower in kinds of communication systems, the requirement of microwave filter's performance for wireless communication is becoming harder and harder. So, the mainly technical requirements for designing microwave filters include low-loss, high isolation, compact size, and low costs.The waveguide filters of Ku-band are researched in this thesis. The main form of Ku-band waveguide is Chebyshev; however, the selectivity of the waveguide filter is limited by this kind. In order to improve the selectivity of the waveguide filter, one way is increasing the filter order. In this thesis, a novel type of waveguide generalized Chebyshev filter is designed. The filter is based on extracted pole theory, then improve the equivalent circuit, it adds parallel resonant to generate transmission zero in the series resonant circuit, uses the transmission characteristics of the partial-height post to realize the transmission zero in waveguide filter at the same time not to increase the filter order, improves the selectivity of the filter in evidence and has the characteristics of designing conveniently, making easily and tuning simply. We do not have the related reports of the waveguide filter structure in the domestic literature.The main works are as follows:1. Systematically analysis the theories of the design of microwave filter, including the transfer functions, low-pass prototype filter, frequency transformations and immittance inverters.2. Introduce the design method of the post waveguide inductance filter, draw the relation of the post's size and its impedance, and give the examples of the simulation design. Detailed analyze the equivalent circuits of the post and the partial-height post, and compare of their equivalent circuits, using the transmission characteristics of the partial-height post, a novel type of Ku-band waveguide generalized Chebyshev filter is designed, and then the simulation results is given. 3. According to the circuit of the extracted pole theory, and its equivalent circuit is improved to realizing the asymmetrical transmission zeros and one transmission zero, a novel filter is designed with waveguide and the equivalent circuits simulation and HFSS simulation is then given.4. According to given specifications, provide design examples of waveguide generalized Chebyshev filters, and present the corresponding simulations and testing results.The generalized Chebyshev waveguide post inductance filter is systemic and deeply discussed in this thesis; it is useful of its development in the future.