In this paper, we present a miniaturized ultra-wideband (UWB) bandpass filter (BPF) with multiple transmission zeros (TZs), which is based on transition technology of microstrip with short-circuited coplanar waveguide (CPW). The ground plane of the BPF contains a multiple mode resonator (MMR)-based CPW which is capacitively linked through the dielectric to two open-circuited microstrip lines on the top. The MMR is initially designed to allocate its lowest three resonant modes quasi-equally inside the designated UWB spectrum (3.1–10.6 GHz). This is followed by optimization of microstrip lines to provide a good broadband response possessing minimum insertion loss, two TZs at the lower and upper passband edges that improve selectivity and a wide stopband with appreciable attenuation. Later, multiple-folded split ring resonators are coupled to the BPF to inject dual passband TZs. The predicted theory in simulation is verified against measured result and is found to be in good agreement. The prototype covers a substrate area of only 14.6 × 9.2 mm2.

在本文中，我们提出了一种具有多个传输零点（TZ）的小型化超宽带（UWB）带通滤波器（BPF），它基于具有短路共面波导（CPW）的微带传输技术。BPF 的接地层包含一个基于多模谐振器 (MMR) 的 CPW，它通过电介质电容连接到顶部的两条开路微带线。MMR 最初设计为在指定的 UWB 频谱（3.1-10.6 GHz）内准相等地分配其最低的三个谐振模式。随后对微带线进行了优化，以提供良好的宽带响应，具有最小的插入损耗、位于下通带边缘和上通带边缘的两个 TZ 可提高选择性以及具有明显衰减的宽阻带。之后，多折叠开口环谐振器耦合到 BPF 以注入双通带 TZ。仿真中的预测理论与实测结果进行了验证，发现其吻合度很好。原型覆盖的基板面积仅为 14.6 × 9.2 mm2 .