Modern radio frequency transceivers need powerful microwave filters that are compact, inexpensive, and able to operate in today’s communication system. Metamaterial (MTM) filters have a small structural footprint, low loss of insertion, and exceptional selectivity and demonstrate excellent performance outside of the band, which is known as band rejection. This chapter presents the strategy and study of compact, planar bandstop filters using a dual composite right/left-handed (DCRLH) MTM transmission line (TL) structure and filters having bandpass response using composite right/left-handed (CRLH) MTM structures. First, a compact bandstop band constructed using a T-shaped circuit of an improved DCRLH resonator is presented. A single cell with a parallel and series tank circuit makes up the resonator. A shorted finger and an interdigital capacitor (IDC) are used to create the parallel inductance-capacitance (LC) tank circuit, while a short circuit stub with an air gap capacitance is used to create the series LC tank circuit. Dispersion analysis, full wave simulation, and circuit modeling are all used to describe the specific filter design. Following that, a coplanar waveguide (CPW) feeding–based bandpass filter based on a CRLH TL is discussed. The resonant zeroth-order features of MTM were used to minimize the filter size in this filter construction, which is developed on a CPW single layer without the need for vias to attach the top and ground planes. A tuning-fork stub connecting the patch to the CPW ground plane is included in the proposed structure, which is symmetrically CPW-fed. Another via-less bandpass filter made of a pi-type equivalent circuit constitutes means due to Inverted IDC is surrounded by a rectangular stub and a symmetrical shunt meander line. IDCs that are inverted produce series left-handed capacitance and right-handed inductance when current flows through them. Left-handed inductance and right-handed capacitance are produced by the ground plane and the parasitic effects of the IDC’s fingers, respectively. The stub of rectangular size functions as a fictitious base and creates a significant capacitance that is linked by a meander line. The electric field distribution reveals that two poles are produced as a result of two meander lines and two rectangular stubs. The length of the meander line determines the position of two transmission zeros before and after the passband. Plotting a dispersion diagram of the suggested structure makes it possible to identify the MTM properties.

Metamaterial-Based Bandstop and Bandpass Filters

动态工具书词条
发表日期：

2026年

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Dilip Kumar Choudhary,
Raghvendra Kumar Chaudhary

摘要

Modern radio frequency transceivers need powerful microwave filters that are compact, inexpensive, and able to operate in today’s communication system. Metamaterial (MTM) filters have a small structural footprint, low loss of insertion, and exceptional selectivity and demonstrate excellent performance outside of the band, which is known as band rejection. This chapter presents the strategy and study of compact, planar bandstop filters using a dual composite right/left-handed (DCRLH) MTM transmission line (TL) structure and filters having bandpass response using composite right/left-handed (CRLH) MTM structures. First, a compact bandstop band constructed using a T-shaped circuit of an improved DCRLH resonator is presented. A single cell with a parallel and series tank circuit makes up the resonator. A shorted finger and an interdigital capacitor (IDC) are used to create the parallel inductance-capacitance (LC) tank circuit, while a short circuit stub with an air gap capacitance is used to create the series LC tank circuit. Dispersion analysis, full wave simulation, and circuit modeling are all used to describe the specific filter design. Following that, a coplanar waveguide (CPW) feeding–based bandpass filter based on a CRLH TL is discussed. The resonant zeroth-order features of MTM were used to minimize the filter size in this filter construction, which is developed on a CPW single layer without the need for vias to attach the top and ground planes. A tuning-fork stub connecting the patch to the CPW ground plane is included in the proposed structure, which is symmetrically CPW-fed. Another via-less bandpass filter made of a pi-type equivalent circuit constitutes means due to Inverted IDC is surrounded by a rectangular stub and a symmetrical shunt meander line. IDCs that are inverted produce series left-handed capacitance and right-handed inductance when current flows through them. Left-handed inductance and right-handed capacitance are produced by the ground plane and the parasitic effects of the IDC’s fingers, respectively. The stub of rectangular size functions as a fictitious base and creates a significant capacitance that is linked by a meander line. The electric field distribution reveals that two poles are produced as a result of two meander lines and two rectangular stubs. The length of the meander line determines the position of two transmission zeros before and after the passband. Plotting a dispersion diagram of the suggested structure makes it possible to identify the MTM properties.