采用直接接触馈电的方法设计制作了一款微带结构的双模带通滤波器。该滤波器采用了分布式电容加载的双模环形谐振器,馈电时不需额外的耦合结构或阻抗变换器,在实现较大耦合量的同时,可保持谐振器的小型化。所制作的单级和两级的滤波器样品分别获得了0.6dB(在22.0%的相对带宽下)和1.1dB的最小插入损耗(在16.7%的相对带宽下)、40.0dB的带外抑制并在通带的两侧各有两个传输零点的较好测试结果,测试值与仿真值相当吻合。测试结果还表明,在得到相对较小的插入损耗的同时,也得到了优于-15.0dB的带内匹配。 Adopting the method of direct contact feeding, a two-mode band-pass filter with microstrip structure was designed and manufactured. The filter uses a distributed capacitance-loaded dual-mode ring resonator without additional coupling structure or impedance converter for feeding, which can keep the resonator miniaturized while realizing a large coupling amount. The fabricated single-stage and two-stage filter samples gave out-of-band rejection of 0.6 dB (at 22.0% relative bandwidth) and 1.1 dB minimum insertion loss (at 16.7% relative bandwidth) On both sides of the passband, there are two good test results of the transmission zero. The test values ​​are in good agreement with the simulation values. The test results also show that in-band matching of better than -15.0 dB is obtained with a relatively small insertion loss.