This article presents a dual notched ultra‐wideband (UWB) bandpass filter (BPF) with good frequency characteristics realized on a low‐cost dielectric. The proposed structure is based on the surface‐to‐surface transition technology, with microstrip lines aligned face‐to‐face on the top, and short‐circuited butterfly shaped coplanar waveguide (CPW) in the ground. The microstrips and CPW are coupled vertically via the dielectric. The basic optimized alignment generates a third‐order UWB filter with quasi‐elliptic response having two transmission zeros at either passband edge and improved insertion/return loss. Later, folded split‐ring resonators are coupled to feed lines of the basic BPF to develop multiple stopbands inside and outside the UWB spectrum. The predicted simulated performance is verified against measured data, which depicts good similarity. The structure covers an area of 21.2 × 16 mm².

中文翻译：

---

具有多个传输零点的基于低成本的微带到共面波导过渡的超宽带带通滤波器

本文介绍了一种双缺口超宽带（UWB）带通滤波器（BPF），该滤波器具有在低成本电介质上实现的良好频率特性。拟议的结构基于表面到表面的过渡技术，顶部的微带线面对面对齐，而地下的蝴蝶形共面波导（CPW）短路。微带和CPW通过电介质垂直耦合。最优化的基本对准将生成具有准椭圆响应的三阶UWB滤波器，在任一通带边缘具有两个传输零，并改善了插入/回波损耗。后来，将折叠的开环谐振器耦合到基本BPF的馈线，以在UWB频谱的内部和外部形成多个阻带。根据测量数据验证了预测的模拟性能，表现出很好的相似性。该结构占地面积21.2×16毫米²。