Miniature coupled resonator UWB filter using a multilayer structure on liquid crystal polymer

This paper presents a novel miniature UWB filter using a three-metal-layer structure on liquid crystal polymer (LCP) substrate. LCP technology is an attractive solution for compact filters. As an organic material, the LCP substrate has impressive electrical characteristics such as a low dielectric loss (loss tan delta= 0.002 - 0.004), nearly static dielectric constant across a very wide frequency range, extremely low water absorption and low coefficient of thermal expansion. It can be used as a low-cost dielectric material for high-volume large-area processing methods that provides very reliable high-performance circuits at low cost. The unique combination of low cost, excellent wideband electrical properties and multilayer capability makes LCP an ideal candidate for developing UWB filters.