Design of Dual-band Branch-Line Coupler Based on Shunt Open-Circuit DCRLH Cells

In this article, the shunt open-circuit dual composite right/left-handed (DCRLH) cell is initially proposed and one dual-band branch-line coupler based on the proposed cells is designed. It is found that, compared with DCRLH cell, the frequency selectivity, matching condition and adjustment range of the shunt open-circuit DCRLH cell improve greatly. Moreover, the shunt open-circuit DCRLH cell exhibits two adjustable frequency points with -90degrees phase shift within its first two passbands. In order to explore this exotic property effectively, the influence of the primary geometrical parameter is investigated through parametric analysis. Thus, one dual-band branch-line coupler based on the shunt open-circuit DCRLH cells is designed. Both simulated and measured results indicate that comparative performance is achieved. Different from part of previous dual-band branch line couplers, for the proposed coupler, the signs of phase difference of two output ports within the two operating frequency bands are identical with each other. This branch-line coupler is quite suitable for the application which is sensitive to the variation of phase difference and its effective area is compact

Quasi-discrete microwave solitons in a split ring resonator-based left-handed coplanar waveguide

We study the propagation of quasi-discrete microwave solitons in a nonlinear left-handed coplanar waveguide coupled with split ring resonators. By considering the relevant transmission line analogue, we derive a nonlinear lattice model which is studied analytically by means of a quasi-discrete approximation. We derive a nonlinear Schr{\"o}dinger equation, and find that the system supports bright envelope soliton solutions in a relatively wide subinterval of the left-handed frequency band. We perform systematic numerical simulations, in the framework of the nonlinear lattice model, to study the propagation properties of the quasi-discrete microwave solitons. Our numerical findings are in good agreement with the analytical predictions, and suggest that the predicted structures are quite robust and may be observed in experiments

Highly Versatile Coplanar Waveguide Line With Electronically Reconfigurable Bandwidth and Propagation Characteristics

[EN] This paper describes a coplanar waveguide coupled to two split-ring resonators that, in turn, are loaded with two different reactive elements. By these means, balanced composite right/left-handed-like (CRLH-like) and also dual balanced CRLH-like (D-CRLH-like) responses can be obtained with the same structure showing opposite propagation characteristics. This behavior is achieved by simply varying one of the reactive elements, i.e., the capacitive or inductive load. The physical behavior of these transmission lines has been successfully explained by means of a single equivalent circuit. Besides, the proposed transmission lines have an extended bandwidth due to the balanced nature of the structure. The bandwidth of these lines can be electronically controlled using varactor diodes reverse-biased by an external dc voltage. Thus, a reconfigurable cell with CRLH-like and D-CRLH-like propagation has been designed and manufactured. The simulated and measured results show fractional bandwidths from 0% (no transmission) to 9.3% for simulations and from 0% (no transmission) to 8.7% for measurements. Undoubtedly, these new proposed transmission lines will be useful for designing reconfigurable devices that can be used in future communication systems such as radar, wireless applications, global positioning systems, or radio-frequency identification systems, among others.This work was supported by the Ministerio de Economia y Competitividad, Spanish Government, under Research Project TEC2013-47037-C05-3-R and Research Project TEC2013-47037-C05-1-R and by the Ministerio de Educacion, Cultura y Deporte under the Fellowship Program for Training University Professors.Martinez Cano, L.; Lucas Borja, A.; Boria Esbert, VE.; Belenguer, A. (2017). Highly Versatile Coplanar Waveguide Line With Electronically Reconfigurable Bandwidth and Propagation Characteristics. IEEE Transactions on Microwave Theory and Techniques. 65(1):128-135. https://doi.org/10.1109/TMTT.2016.2613526S12813565

Mode structure in superconducting metamaterial transmission-line resonators

FUNDAÇÃO DE AMPARO À PESQUISA E INOVAÇÃO DO ESTADO DE SANTA CATARINACNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOSuperconducting metamaterials are a promising resource for quantum-information science. In the context of circuit QED, they provide a means to engineer on-chip dispersion relations and a band structure that could ultimately be utilized for generating complex entangled states of quantum circuitry, for quantum-reservoir engineering, and as an element for quantum-simulation architectures. Here we report on the development and measurement at millikelvin temperatures of a particular type of circuit metamaterial resonator composed of planar superconducting lumped-element reactances in the form of a discrete left-handed transmission line that is compatible with circuit QED architectures. We discuss the details of the design, fabrication, and circuit properties of this system. As well, we provide an extensive characterization of the dense mode spectrum in these metamaterial resonators, which we conduct using both microwave-transmission measurements and laser-scanning microscopy. Results are observed to be in good quantitative agreement with numerical simulations and also an analytical model based upon current-voltage relationships for a discrete transmission line. In particular, we demonstrate that the metamaterial mode frequencies, spatial profiles of current and charge densities, and damping due to external loading can be readily modeled and understood, making this system a promising tool for future use in quantum-circuit applications and for studies of complex quantum systems.115120FUNDAÇÃO DE AMPARO À PESQUISA E INOVAÇÃO DO ESTADO DE SANTA CATARINACNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFUNDAÇÃO DE AMPARO À PESQUISA E INOVAÇÃO DO ESTADO DE SANTA CATARINACNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOSem informaçãoSem informaçãoAgências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig

Double-sided open split ring resonator for compact microstrip band-pass filter design

A metamaterial structure, called the double-sided open split ring resonator (DOSRR), which combines two open split ring resonators (OSRRs) aligned over the opposite faces of the substrate in an inverted fashion is presented. A study of this resonator from full-wave electromagnetic and circuit simulations is performed. As with the OSRR cell, the DOSRR cell allows a series connection along a microstrip transmission line and it has a small electrical size. Moreover, the DOSRR cell has the ability to add a transmission zero in the out-of-band region without increasing its size. This DOSRR cell is used for the design of compact microstrip slow-wave type band-pass filters. Two strategies based on circular windows etched in the bottom plane instead of square windows and U-shape slots etched in the microstrip transmission line are designed to increase the stop band and to add extra zeros in order to suppress the spurious band. The experimental results have confirmed the possibilities of this electrically small resonator (DOSRR) and the efficiency of both strategies to improve the out-of-band rejection.The authors gratefully acknowledge Ministerio de Ciencias e Innovación of Spain for financial support of this work under the grant no.: TEC2010-21520-C04-04/TCM

Coupled CRLH transmission lines for compact and high selectivity bandpass filters

A compact size and high selective bandpass filter is presented in this paper. The filter is designed to serve at 3.5 GHz with two transmission zeros at 3.35 GHz and 3.85 GHz. The filter is designed as two gap capacitor coupled to two coupled composite right–left handed transmission lines. The coupled lines were designed to demonstrate a zeroth order phase at 3.5 GHz. Also, the transmission zeros were achieved as a consequence of the electrical/magnetic couplings between the two coupled transmission lines. The employed cell, filter design equations are emphasized. The filter S-parameters were extracted based on the circuit model, full wave simulation, and experimental measurements. A good agreement between modeled, simulated, and measured results is achieved. The measured center frequency of the bandpass filter is 3.55 GHz and 100 MHz bandwidth which is suitable for WiMAX applications. Also, the filter has low measured insertion loss which does not exceed 1 dB within passband. Finally, the filter has advantages of compactness (size is 20 3 18 mm2) which is only 50% compared to conventional non-selective one-stage coupled line filter

Metamaterial Antennas for Wireless Communications Transceivers

Limited space is given to antennas in modern portable wireless systems, which means that antennas need to be small in size and compact structures. However, shrinkage of conventional antennas leads to performance degradation and complex mechanical assembly. Therefore, the design of miniature antennas for application in wireless communication systems is highly challenging using traditional means. In this chapter, it is shown that metamaterial (MTM) technology offers a solution to synthesize antennas with a small footprint with the added advantage of low cost and excellent radiation characteristics