Complementary Split-Ring Resonators for Measuring Dielectric Constants and Loss Tangents

In this paper, three dual notch microwave sensors are presented based on a microstrip transmission line and complementary metamaterial resonators. The main aim of this paper is to compare the constitutive parameters and sensitivity of all three dual notch sensors which are based on complementary symmetric split ring resonator (CS-SRR), complementary asymmetric split ring resonator (CAS-SRR) and complementary bisymmetric split ring resonator (CBS-SRR). The main motivation beyond the presented work is to use dual notches to estimate the relative permittivity of material under test (MUT). Electromagnetic simulation elucidates the origin of dual mode resonance of all the three resonators. Sensitivity analysis is performed on each sensor by using fifteen MUTs with relative permittivity ranges from 1.006 to 16.5 and constant dimensions 10 mm × 10 mm × 1 mm. To verify the concept, a sensor is fabricated and its response is measured using a vector network analyzer (AV3672). Using curve fitting technique the shift in the resonance frequencies of the fabricated sensor due to interaction with MUT is presented as a function of permittivity. Simulated, measured and formulated results are in good agreement with each other.

A simple method for dielectric constant characterization is the full sheet resonance method. In this technique, the dielectric constant is extracted from the resonance frequencies of a parallel-plate waveguide resonator. The standard method cannot be applied to extract the loss tangent. Recently, the full-sheet resonance method has been extended to extract the loss tangent as well. The new method makes use of a new rapid plane solver and resonators with shorted boundaries. The materials properties are extracted by fitting the simulations to measurements. In this paper, we will demonstrate how the fitting process can be automated. In order to extract the dielectric constant and loss tangent, many simulations need to be run to find the parameters that provide the best match with the measurements. This is a computationally expensive approach. We will present a new method based on tracking sensitivity, which provides a parameterized macromodel for the resonators. Using this approach, the simulation data can be expressed as a low-order rational function of the complex permittivity. Hence, varying the complex permittivity to find the best fit can be done in negligible time after the macromodel has been generated. This new method will be applied to extract the dielectric constant and loss tangent of FR-4.

A novel composite right-/left-handed transmission line (CRLH TL) and its equivalent circuit model are proposed based on cascaded complementary single split ring resonator (CCSSRR). It features an intrinsically balanced wider band and an additional transmission zero above the right-handed band relative to CRLH TL using complementary single split ring resonator and complementary split ring resonators. Moreover, two single negative (SN) metamaterial (MTM) TLs constructed by using complementary electric inductive-capacitive resonator on the conductor strip and on the ground, respectively, are researched. Both SN MTM TLs exhibit electric resonance above the fundamental magnetic resonance. For application, a monoband (MB) bandpass filter (BPF) covered WLAN band, and a dual-band (DB) BPF covered satellite DMB band and WiMAX band are designed, fabricated, and measured. The SN MTM TLs are adopted for the sake of deep and wide out-of-band suppression while CRLH MTM TLs using square-shaped and Sierpinski-shaped CCSSRR are critical factors of the MB and DB behavior. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012. © 2012 Wiley Periodicals, Inc.

A simple dual-band antenna design and implementation method is proposed in this work, based on the equivalent media properties inspired by resonant metamaterial elements. The equivalent circuit model of dual-band patch antennas based on a complementary split ring resonator (CSRR) is presented and validated. The dual-band patch antenna is designed etching a CSRR in the patch of a conventional rectangular microstrip patch antenna. The first resonance is governed by the quasi-static resonance of the CSRR while the second resonance is originated by the rectangular patch. The fact of etching a CSRR on a rectangular patch antenna also produces a miniaturization of a conventional patch antenna. The equivalent circuit model proposed in this letter is sound in order to understand the functionality of dual-band patch antennas based on a CSRR. Good agreement between simulation, equivalent circuit model and experimental results is shown and discussed. These results lead the equivalent circuit model to become a simple and straightforward tool for the design of this type of multiband antennas, of low cost and versatile operation for a broad range of wireless communication systems.

This article proposes the design, fabrication and measurement of a triple-rings complementary split-ring resonator (CSRR) microwave sensor for semi-solid material detection. The triple-rings CSRR sensor was developed based on the CSRR configuration with curve-feed designed together, utilizing a high-frequency structure simulator (HFSS) microwave studio. The designed triple rings CSRR sensor resonates at 2.5 GHz, performs in transmission mode, and senses shift in frequency. Six cases of the sample under tests (SUTs) were simulated and measured. These SUTs are Air (without SUT), Java turmeric, Mango ginger, Black Turmeric, Turmeric, and Di-water, and detailed sensitivity analysis is conducted for the frequency resonant at 2.5 GHz. The semi-solid tested mechanism is undertaken using a polypropylene (PP) tube. The samples of dielectric material are filled into PP tube channels and loaded in the CSRR centre hole. The e-fields near the resonator will affect the interaction with the SUTs. The finalized CSRR triple-rings sensor was incorporated with defective ground structure (DGS) to deliver high-performance characteristics in microstrip circuits, leading to a high Q-factor magnitude. The suggested sensor has a Q-factor of 520 at 2.5 GHz with high sensitivity of about 4.806 and 4.773 for Di-water and Turmeric samples, respectively. The relationship between loss tangent, permittivity, and Q-factor at the resonant frequency has been compared and discussed. These given outcomes make the presented sensor ideal for detecting semi-solid materials.

In this letter, a high-sensitivity microwave sensor based on a complementary split-ring resonator (CSRR) is proposed. The dual interdigital electrodes (IDEs) are loaded in the CSRR, and the serrated structure (SS) is inserted into the IDE, which can further improve the electric field aggregation ability and generate strong electric field constraints. Sample containers made of acrylonitrile-butadiene–styrene (ABS) plastic are placed throughout the CSRR to capture the largest electric field changes. The equivalent circuit model is established and analyzed. The curves of complex permittivity versus resonant frequency and peak attenuation are fit. The fit curve is tested using an ethanol-water solution and verified using the methanol-water solution. The results show that the measured complex permittivity values are highly consistent with the complex permittivity values given in the literature. The average sensitivity of the proposed sensor is as high as 2.28%. The average errors of the real and imaginary parts of the complex permittivity are 1.45% and 2.16%, respectively.

This paper proposes a new triple-band monopole antenna based on Complementary Split Ring Resonators (CSRR) perturbing the ground plane (GND). The antenna consists of an inverted-L-shaped monopole fed by a modified microstrip line with two CSRRs cut out of the ground plane. The operational bands are independently controlled by the CSRR unit cell parameters. In addition, the antenna presents a dual-polarization performance (vertical polarization at 2.4 GHz band and horizontal polarization at both 3.6 and 5.9 GHz bands). The designed antenna is fully planar and low profile avoiding the vias with the ground plane and covering the WLAN, WiMAX, and IEEE 801.11p bands at 2.45, 3.6, and 5.8 GHz. A compact prototype (0.32λ0 × 0.32λ0 being λ0 is the wavelength corresponding to the lowest resonance frequency) has been fabricated and measured showing good agreement between simulations and measurements. The measured impedance bandwidths are 10% (2.38-2.63 GHz), 2.5% (3.54-3.63 GHz), and 20% (5.83-7.12 GHz) whereas the measured gains are 1.34, 0.68, and 2.65 dBi at 2.4, 3.6, and 5.9 GHz respectively.

This study focuses on the measurement and analysis of the complex permittivities of polymer blends using the field enhancement method (FEM). The blends, consisting of air-powder or solvent-solute mixtures, are placed in a Teflon holder and inserted into the FEM cavity to determine the complex permittivity. The resonant frequency and quality factor of the FEM cavity coupled with the samples provide information on the blends' dielectric constant and loss tangents. To extract the complex permittivities of three specific samples of DC-840, MCL-805, and MCL-Siloxane, we employ effective medium theories and the high-frequency structure simulator (HFSS) together with the measured data. The results reveal that when the volume fraction of the DC-840 solute in the xylene solvent surpasses a specific threshold, the dielectric constants and the loss tangents experience a notable increase. This phenomenon, known as percolation, strongly correlates with the viscosity of polymer blends. The observed percolation effect on the dielectric behavior is further elucidated using the generalized dielectric constant and the Debye model. By employing these models, the percolation effect and its impact on the dielectric properties of the blends can be explained.

In this paper, we present a new design of miniaturized printed microstrip antenna based on Complementary Split ring resonators (CSRR) as main radiators. The antenna is composed of a pair of CSRRs etched on the ground plane and excited by an open-ended microstrip line feed symmetrically placed between the two CSRRs at the upper substrate side. To enhance the inherently CSRRs limited bandwidth; two rectangular slots are introduced in the vicinity of each CSRR resulting in a significant bandwidth improvement and also in lowering the operating frequency. The resonance frequency of the antenna is essentially defined by geometrical parameters of the CSRR, which makes it suitable for a broad range of applications spanning from mobile terminals to WLAN and WPAN systems. The proposed structure has been studied numerically by using CST Microwave studio.

Substrate Integrated Waveguide)와 상보적 분할링 공진기(CSRR: Complementary Split Ring Resonator)를 기반으로 한 전기적으로 작은 안테나를 제안한다.안테나의 전기적 크기는 CSRR 과 기존 SIW의 1/8크기인 Eighth-Mode Substrate Integrated Waveguide(EMSIW)를 적용하여 줄일 수 있었다.EMSIW는 기존의 SIW와 비교하였을 때

It is shown in this paper that a microstrip line loaded with a dumbbell-shaped defect ground structure (DB-DGS) is useful for complex permittivity measurements. The working principle of the sensor is the variation in the notch (resonance) frequency and depth caused by the material under test (MUT), when it is put in contact with the sensitive region of the device, i.e., the capacitive slot. It is demonstrated that the relative sensitivity of the sensor, defined as the variation of the resonance frequency of the DB-DGS with the dielectric constant of the MUT relative to the resonance frequency of the bare structure, does not depend on the geometry of the DB-DGS, provided the substrate is thick enough. The relative sensitivity, the key figure of merit, is dictated by the equivalent dielectric constant of the substrate, and it increases as the substrate permittivity decreases. Using the circuit model of the sensing structure, simple analytical expressions providing the dielectric constant and the loss tangent of the MUT are derived. Such analytical formulas depend on the notch frequency and depth of the sensor with and without MUT in contact with it, i.e., easily measurable quantities. The analysis carried out is corroborated through full-wave electromagnetic simulation and experiments.

In this contribution, a method for material characterization based on polarimetric measurements is presented. The material under test (MUT) is characterized using two millimeter wave (mmWave) frequency modulated continuous wave (FMCW) radar sensors, which are operating from 68 GHz to 93 GHz. The sensors measure the transmission and reflection coefficients at an oblique angle of incidence of the MUT for orthogonal polarizations. The dielectric constant and losses of the MUT are then calculated from the polarimetric transmission and reflection factors.

Offset-fed complementary split ring resonators loaded monopole antenna for multiband operations

we report our investigation on third harmonic generation (THG) in the terahertz (THz) regime using double resonant frequency selective metasurface composed of square-shaped periodic complementary single split ring resonators.

Electromagnetic (EM) waves are used in the oil and gas industry to identify the geology of the formation and the type of the fluid saturating the medium. There is also an interest to use the electromagnetic waves as an enhanced oil recovery (EOR) method. However, interpretation of logging data generated through electromagnetic waves or determination of the electromagnetic wave propagation in a medium as an EOR method are not easy tasks. This study aims to identify the role of different geological settings with different types of fluid saturations in the response of electromagnetic wave propagation and absorption. To reach this objective multitude-systematic laboratory scale experiments were conducted on different reservoirs fluid and rock pairs. As reservoir mineralogy, different grain size of quartz, clay, or limestone is used to prepare the reservoir rocks at different porosity. Water is known as a good absorber for EM waves, thus, pore space were saturated at different water saturations and a bitumen sample (10,000 cP, 12° API) from Canada. Prepared samples were packed into in-house-built-Plexiglas core holder which allows measurements with EM waves. The response of EM waves propagation and absorption was measured by using a vector network analyzer at varying frequencies (500 MHz to 4 GHz) through dielectric properties (dielectric constant, loss tangent, and penetration depth). The results were used to obtain correlations between dielectric properties and physical properties (reservoir rock mineralogy, porosity, water saturation, and oil saturation) of the reservoir rock-fluid blends. Water saturation gives a perfect correlation with dielectric constant and loss tangent values of the saturated medium. Because dielectric constant and loss tangent parameters provide an idea on the absorption characteristics of EM wave in the medium, and because water is a strong EM wave absorber, as it was expected, with the increase in water saturation, the dielectric constant and loss tangent parameters of the medium are also increased; on the other hand, penetration depth was decreased. With the increase in quartz content in the medium, it has been observed that EM wave penetration is enhanced. As a result, several correlations were created in this study and they can be used to better interpret the reservoir mineralogy and fluid saturation as a response to EM wave logging. Moreover, these results can be used to estimate the effective area (penetration depth) of EM wave as an EOR method in different mediums.