Miniaturized High-Pass Filter Based on Balanced Composite Right-Left Handed Transmission Line Using Meander Spiral Complementary Split Ring Resonators

In this paper, a compact high-pass filter (HPF) with a sharp rejection response based on the balanced composite right-left handed (CRLH) transmission line (TL) concept is proposed. A series LC resonator using an interdigital capacitor and meander lines is designed. Also, a meander spiral complementary split ring resonator (MSCSRR) is used to realize the parallel LC resonator. The high-pass filter is implemented in microstrip technology by etching MSCSRR, in the ground plane, and series interdigital capacitor with meander lines, in the signal strip. Because of a smaller electrical size of the proposed MSCSRR and also by using meander lines instead of conventional transmission lines, the total physical dimension of the proposed high-pass filter has been reduced. A detailed analysis of the structure, based on the equivalent circuit model is provided. The structure exhibits a balanced CRLH behavior and by properly tuning the geometry of the elements, a high-pass response with a sharp transition band is obtained. To validate the design concept, the proposed high-pass filter has been fabricated and tested. Experimental verification is provided and a good agreement has been found between the simulation and measurement results. To our knowledge, the size of proposed HPF is more compact in comparison with known similar filters.

Keywords:

metamaterial , balanced composite right-left handed transmission line (CRLH TL) , meander , meander spiral complementary split ring resonator (MSCSRR) , high-pass filter (HPF) , and compact size