A continuously tunable Ku-band waveguide diplexer is proposed in this paper. This diplexer is based on a hybrid coupler topology and is composed of an input filter centered at 11.9 GHz with a 200 MHz bandwidth, a pair of ladder-type hybrid couplers, and a pair of tunable filters. This diplexer can provide two bandpass channels (channels 1 and 2) that can continuously go from a state where the bandwidths of channels 1 and 2 are maximum (up to 140 MHz) and minimum (down to 40 MHz), respectively, to another configuration where the bandwidth of channel 1 is the largest and the bandwidth of channel 2 is the narrowest. We propose a tunable filter based on TE012 mode circular cavities that are perturbed by low-loss dielectric inserts to obtain such performance. The resonant frequency of these cavities can be continuously tuned between 11.8 and 12 GHz due to the linear movement of the dielectric perturber. The design process for these components is presented and a breadboard device has been manufactured and measured to prove the concept. Different measured configurations of the diplexer are demonstrated, showing that the 200 MHz operating bandpass between 11.8 and 12 GHz can be efficiently separated into two tunable channels. The measured bandwidth of channels 1 and 2 in the manufactured diplexer can be tuned from 135 to 40 MHz (and vice versa) while maintaining an average guard band between the channels of approximately 26 ± 7 MHz. The obtained bandwidth tuning ratios are 3.2 for the highest channel and 3.1 for the lowest channel.

本文提出了一种连续可调的Ku波段波导双工器。该双工器基于混合耦合器拓扑结构，由一个中心频率为 11.9 GHz、带宽为 200 MHz 的输入滤波器、一对梯型混合耦合器和一对可调谐滤波器组成。该双工器可以提供两个带通通道（通道 1 和 2），可以连续从通道 1 和 2 的带宽分别为最大（最高 140 MHz）和最小（低至 40 MHz）的状态转到另一种配置其中通道 1 的带宽最大，通道 2 的带宽最窄。我们提出了一种基于 TE 012的可调滤波器模圆形腔受到低损耗介电插入物的扰动以获得这种性能。由于电介质扰动器的线性运动，这些空腔的谐振频率可以在 11.8 和 12 GHz 之间连续调谐。介绍了这些组件的设计过程，并制造并测量了一个试验板设备以证明这一概念。演示了双工器的不同测量配置，表明 11.8 和 12 GHz 之间的 200 MHz 工作带通可以有效地分离成两个可调谐通道。制造的双工器中通道 1 和 2 的测量带宽可以从 135 调谐到 40 MHz（反之亦然) 同时保持通道之间的平均保护频带约为 26 ± 7 MHz。获得的带宽调谐比对于最高通道为 3.2，对于最低通道为 3.1。