Split ring resonator-based left-handed coplanar waveguide

In this paper we purpose a triangular split ring resonator (TSRR) loaded with co-planar waveguide (CPW) line for realizing a planar band-pass filter for miniaturization and high data rate WiMAX communication system. It consists of a 50Ω CPW line with triangular resonator etched on backside of substrate, parallel to the CPW. Because of negative permeability offered by the SRR and series capacitance this structure exhibits backward wave propagation in the vicinity of its resonant frequency. Due to the strong inductive coupling between resonator and line and periodically loading the line with narrow wires, resulting high selectivity with low insertion loss in the wide band-pass characteristic.

A novel compact stop band filter consisting of a 50 /spl Omega/ coplanar waveguide (CPW) with split ring resonators (SRRs) etched in the back side of the substrate is presented. By aligning SRRs with the slots, a high inductive coupling between line and rings is achieved, with the result of a sharp and narrow rejection band in the vicinity of the resonant frequency of the rings. In order to widen the stop band of the filter, several ring pairs tuned at equally spaced frequencies within the desired gap are cascaded. The frequency response measured in the fabricated prototype device exhibits pronounced slopes at either side of the stop band and near 0 dBs insertion loss outside that band. Since SRR dimensions are much smaller than signal wavelength, the proposed filters are extremely compact and can be used to reject frequency parasitics in CPW structures by simply patterning properly tuned SRRs in the back side metal. Additional advantages are easy fabrication and compatibility with MMIC or PCB technology.

Coplanar waveguide (CPW) transmission lines periodically coupled to split‐ring resonators (SRRs) are analyzed, designed, and characterized. Due to inductive coupling between the lines and SRRs, signal propagation is inhibited in the vicinity of the resonant frequency of the rings. The result is a stop‐band behavior that can be of interest for the elimination of frequency parasitics in CPW‐based devices. Two different approaches are envisaged: a uniplanar structure, where CPW and rings share the same metal level; and a bimetal structure with SRRs etched on the back side of the substrate. It has been found that the latter exhibits almost negligible insertion losses in the pass band, and sharp cutoff and a high level of rejection in the stop band, with few unit cells. Since ring dimensions are small compared to the signal wavelength at resonance, the proposed SRR‐CPWs are very promising for the design of miniaturized microwave circuits. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 3–6, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11269

Excellent Electromagnetic performance of Microstrip Antenna motivates researchers for its optimization. The manuscript suggests the technique to miniaturize patch antenna using Split Ring Resonator and Thin Wire Metamaterial. The Unit Cell of SRR and TW is inserted below the patch mounted on the air substrate. The patch without Metamaterial resonates at 6 GHz giving gain of 6 dB over the impedance band of 700 MHz. When the same patch is loaded with SRR and TW magnetic inclusion enhances the permeability which reduces effective operating wavelength. With increase in effective permeability imbalance between electric and magnetic field reduces. Thus reduces operating frequency. The insertion of SRR and TW reduces operating frequency to 1.84 GHz form 6 GHz for the same patch dimensions. At 1.84 GHz as well patch gain is around the 6 dB over the impedance band of 600 MHz. As insertion of magnetic material changes permeability, proper orientation of SRR can be adjusted to maintain mode of an antenna to obtain desired antenna radiation efficiency. The experimental results shows good agreement to the simulated one. The measured miniaturization factor is approximately 65 %. The main limitation of the proposed technique is that it operates over the narrow band of frequencies as Metamaterial is basically narrow band in nature.

In this article, a bandpass filter (BPF) is proposed by etching stepped impedance complementary split ring resonators (SICSRRs) pairs in parallel with series gaps on the top side of a coplanar waveguide (CPW). The Nicolson-Ross-Weir (NRW) method is used to analyze the left-handed (LH) behavior of the filter. The effects of the resonators parameters on the left-handed BPF are studied. The parameters and number of the resonators are adjusted properly to obtain the desired filter characteristics. Split ring resonators (SRRs) are magnetically coupled to the BPF to realize a novel left-handed dual-band bandpass filter. Besides, The dual-band filter is described by means of the lumped-element equivalent circuit model. Also, the quasi-static analysis is used to obtain the equations for the resonant frequencies of the resonators. The efficient electrical size of the dual-band filter is 0.51λg × 0.42λg where λg represents the guided wavelength at the first passband center frequency. The prototype of the compact dual-band BPF is fabricated and measured. The measured results reveal low insertion loss and high return loss at the passbands along with wide upper stopband attenuation. The measured result is in a good agreement with the corresponding simulation result.

Abstract240 GHz operated meta‐surface band pass filter consisting of split‐ring resonator (SRR) matrix was simulated and measured as single and second order modes. The filter was integrated with hemispherical and Luneburg type of antenna lenses. The SRR meta‐material filter was recommended component for 6G telecommunication applications characterizing measured values of 80 GHz bandwidth, low insertion loss (−0.75 dB) and good attenuation (−8 dB) characteristics close to the band pass region, and the filters can be cascaded to enhance its filtering characteristics.

The accurate measurement of the angular displacement and velocity of reaction wheels is necessary for attitude (orientation) control in space vehicles (satellites). In this paper, microwave, contactless, and low-cost (as compared to optical encoders) sensors useful for that purpose are analyzed in detail. The sensor consists of a rotor and a stator. The rotor is a disk (or a circular crown) of dielectric material, where one or several arrays of equidistant single-loop split ring resonators (SRRs) are etched along its edge, forming circular chains of hundreds of SRRs. The stator is a coplanar waveguide (CPW) also loaded with pairs of single-loop SRRs (etched in the back substrate side), with the centers located in the slot region. The sensing principle is based on the amplitude modulation of a harmonic (single-tone continuous wave) feeding signal, achieved when the chains of the rotor are displaced over the SRR pairs of the stator. Both sensor elements (rotor and stator) must be parallel oriented, with the SRR pairs of the CPW in close proximity to the SRR chains of the rotor (and rotated 180°), in order to favor their coupling. By this means, the transmission coefficient of the CPW is varied by the circular motion of the rotor, and significant amplitude modulation of the feeding signal is achieved. From the envelope function, the angular velocity can be accurately determined. With the proposed sensors, instantaneous and practically unlimited rotation speeds can be measured.

New coplanar waveguide (CPW) filters with a forkshaped defected ground structure (DGS) are proposed for radio-frequency (RF) and microwave applications.The miniature CPW DGS filters developed are based on the silicon technology.The filters are able to provide the bandstop characteristics with high attenuation in the stop band and low insertion loss in the pass band.A typical filter designed for Ka-band satellite communication systems exhibits an attenuation of 26.3 dB at a resonant frequency of 28.35 GHz.

This paper is focused on the application of open split ring resonators (OSRRs) and their dual counterparts, open complementary split ring resonators (OCSRRs), to the synthesis of composite right/left-handed transmission lines, that is, artificial lines exhibiting backward wave propagation at low frequencies and forward wave propagation at high frequencies. Due to the small dimensions of these resonators, the resulting lines are very compact. Several artificial lines, with different electrical characteristics and topologies, are reported as illustrative examples. It is shown that these artificial lines can be applied to the synthesis of dual-band components and bandpass filters, and two prototype device examples are designed and fabricated in coplanar waveguide technology: a dual-band impedance inverter applied to a dual-band power divider, and an order-3 wide-band bandpass filter. Finally, it is also demonstrated that OSRRs and OCSRRs can be combined for the synthesis of band pass filters in microstrip technology. Since OSRRs and OCSRRs are described by means of series and shunt resonant tanks, respectively, and they are electrically small, their potential to the design of semi lumped planar microwave devices is very high.

We propose and discuss a compact bandpass filter in coplanar waveguide (CPW) loaded with rectangular split-ring resonators (SRRs). The proposed device is designed on a planar structure where the rectangular SRRs and CPW are arranged in the different side. Basic characteristics of the proposed device such as 2-factor, insertion loss, and out of band rejection are considered for X-Band radar operation. Analysis of rectangular shape of SRRs on filter performance is done with emphasis on coupling between adjacent SRRs. The proposed device has a small size which is good for miniaturization and has promising feature for applications in X-Band radar transceiver module. It can be easily fabricated by using standard photo-etching techniques.

This paper presents the design and analysis of a broad-band patch antenna using split ring metamaterial. The SRR metamaterial structures are embedded in a unique and novel way in the patch antenna, so that subwavelength modes get introduced in the patch cavity and a broad bandwidth antenna with good performance characteristics is obtained. A rectangular microstrip patch antenna is taken as a reference antenna, which resonates at a frequency of 5.2 GHz and has an impedance bandwidth of 70 MHz. To improve the bandwidth of the patch antenna, firstly the split ring resonator (SRR) is designed according to the reference patch antenna. The optimized SRR metamaterial is placed in between the patch and ground plane of the proposed antenna. The – 10 dB impedance bandwidth of the metamaterial-embedded proposed antenna is 1.63–4.88 GHz and has an average gain of 4.5 dB. The Prototype of the proposed antenna and reference antenna is fabricated and experimental results are obtained. Experimental and simulated results are in good agreement. The presented antenna can be used for LTE, GSM, WiMAX, Bluetooth, and other wireless applications.

We propose a chip-integratable cylindrical vector (CV) beam generator by integrating six plasmonic split ring resonators (SRRs) on a planar photonic crystal (PPC) cavity. The employed PPC cavity is formed by cutting six adjacent air holes in the PPC center, which could generate a CV beam with azimuthally symmetric polarizations. By further integrating six SRRs on the structure defects of the PPC cavity, the polarizations of the CV beam could be tailored by controlling the opening angles of the SRRs, e.g., from azimuthal to radial symmetry. The mechanism is governed by the coupling between the resonance modes in SRRs and PPC cavity, which modifies the far-field radiation of the resonance mode of the PPC cavity with the SRR as the nano-antenna. The integration of SRRs also increases the coupling of the generated CV beam with the free-space optics, such as an objective lens, promising its further applications in optical communication, optical tweezer, imaging, etc.

An advanced isolation control technique is proposed for a terahertz (THz) multi-input multi-output (MIMO) antenna, significantly enhancing port-to-port isolation. This approach utilizes a silicon-based dielectric resonator antenna for high-performance tunable THz MIMO system. The design follows a structured evolutionary process, beginning with a dual-feed (DF) configuration without a dielectric resonator as the baseline model. Enhancements were introduced by incorporating a graphene metal coating, improving tunability and isolation. Further refinements involved integrating a split square ring resonator without an RDRA, enhancing isolation and polarization characteristics. The design was then optimized by introducing a metal-coated RDRA, improving gain, radiation efficiency, and circular polarization purity. Additionally, a complementary split ring resonator-loaded circularly polarized DF structure was incorporated for further performance enhancement. The proposed MIMO antenna achieves 25.5 dB isolation at 7.2 THz without a metal coating. By applying a graphene coating, isolation increases to 49 dB at 7.42 THz, using graphene’s tunable conductivity under an external DC bias for dynamic reconfiguration. The antenna exhibits excellent pattern diversity, with an envelope correlation coefficient below 0.003 and a diversity gain of 9.94 dB. Further isolation improvement is achieved by integrating a split-ring resonator on the dielectric material, enhancing isolation up to 59 dB. These advancements make the proposed antenna highly suitable for THz applications.

This paper presents the verification of left handed propagation in planar left handed transmission lines implemented using only periodic shunt inductive load. In other words, the implemented left handed transmission line was designed with no series capacitive load. The left handed transmission line was designed on a ferrite substrate in coplanar waveguide configuration. The ferrite substrate is horizontally magnetized which has small demagnetization factor and hence it requires small external DC magnetic bias. The equivalent negative permeability was obtained thanks to the ferrite negative permeability according to the ferrite magnetic properties and the applied DC magnetic bias. The design concepts for this kind of transmission lines have been explained theoretically. The left handed transmission propagation verification along the transmission line has been done using both the transmission characteristics and electric field profile. The transmission characteristics results, for different DC magnetic bias values, confirms that the transmission coefficient (S 21 ) gains up to 15 dB increase in its value within the frequency band of ferrite negative permeability. Also, the electric field profile emphasize illustrates the negative phase associated with left-handed propagation

This paper presents a theoretical and numerical study of a reconfigurable high‐quality (Q) split‐ring resonator (SRR)‐based microwave sensor for detecting the conductivity of 2D carbon materials, specifically single‐layer graphene (SLG) and reduced graphene oxide (rGO). The proposed sensor, integrated into a coplanar waveguide (CPW) circuit, enables tunable resonance through angular rotation of the SRR. Among the resonant modes, the deep resonance of the SRR configuration is analytically investigated using a coupled‐mode theory (CMT) model. The specific SRR configuration achieves a high Q‐factor (≈191), with excellent agreement between simulation and CMT model (R2 ≥ 0.95). The sensing performance of high‐Q SRRs loaded with SLG and rGO is evaluated across a wide conductivity range from 1 × 102 to 5 × 107 S m−1. The simulated results clearly resolve rGO and SLG films within their respective conductivity ranges 1–5 × 103 S m−1 and 1–5 × 105 S m−1 with both resonant frequency and amplitude strongly dependent on conductivity. As a result, these findings demonstrate the feasibility of the proposed high‐Q SRR device as a compact, sensitive, and miniaturized platform for microwave characterization of ultrathin films, providing a robust foundation for future experimental implementation.