一种基于介质集成波导腔的小型化滤波器

为了实现介质集成波导滤波器的进一步小型化,通常要改进其谐振腔；通过在传统的介质集成波导谐振腔中心位置插入一个短路销钉,并且将其上金属平面与腔体四周的金属壁绝缘可以实现其体积的小型化.采用这种小型化谐振腔,设计了四腔微带滤波器,工作在2.8 GHz,相对带宽14.3％.最终加工了这个原型滤波器,仿真和测试结果吻合良好.相比采用传统的介质集成波导谐振腔的滤波器,这个滤波器尺寸可以减小到其1/4以下.

Compact filter based on substrate integrated waveguide cavities

To achieve the further miniaturization of substrate integrated waveguide filter,some improvements usually are made to the resonator of the substrate integrated waveguide.By inserting a shorting pin to the centre of the conventional substrate integrated waveguide cavity and insulating the top metal plane of the substrate integrated waveguide cavity from the metal side-wall around the cavity,a compact substrate integrated waveguide cavity is achieved.Then a four-cavity bandpass filter which adopts the compact substrate integrated waveguide cavity operating well in 2.8 GHz with 14.3% fractional bandwidth is designed.Finally,a prototype filter is fabricated and tested.The simulation result is consistent with the measured one.The size of the proposed filter is reduced down to a quarter of the filter with the adoption of traditional substrate integrated waveguide cavity.