在本論文中所設計的基板合成波導濾波交叉器，將有其電路設計原理、模擬結果與實作結果探討。 ;In this paper, two third-order substrates waveguide bandpass filter channels are arranged in a cross arrangement used to synthesize the crossover. By combining the four dual-mode resonant cavities which have same structure and the TE_102 and TE_201 orthogonal degenerate mode in the intersecting cavity. The passband transmission with expected bandwidth and excellent isolation can be realized by the input and output ports and the coupling window arranged in the center of the cavity. Adjusting the length and width of the feed line and the width of the coupling window, the bandwidth of the filtering crossover can be easily controlled. Furthermore replacing the four dual-mode resonant cavities to TE_101 mode and couple with the intersecting cavity. Not only can achive the same bandwidth and the same excellent isolation, the TE_101 mode cavity significantly reduces the circuit area, but also improve more flexibly controlled bandwidth.
In this article, the vias are placing in the center of the coupling windows in order to improve the isolation. It can be found that changing the diameter of the centered vias has a considerable influence on the isolation, and then it can also be found that the circuit with a centered vias has better isolation compare with a circuit without a centered vias under the same bandwidth, by adjusting the width of the coupling windows to achieve the same conditions.
The substrate integrated waveguide filtering crossover designed in this paper ,all the design principles, simulation and measure results of the circuits will be discussed.
