Novel resonator based on composite right/left-handed transmission lines

A new approach was introduced to analyze composite right/left-handed transmission lines （CRLH TLs）. The Bloch impedance and the dispersion relations are directly obtained from the S parameters of the unit cells. The LH and RH frequency bands are then identified by the real parts of the Bloch impedance and the phase delay of the unit cells. The new approach has some advantages over the LC parameters extraction method introduced by Caloz et a1.（2004）. Based on the new approach, a novel resonator is designed using CRLH TLs. The simulation and experimental results accorded well with the theoretical analysis. The novel resonator may have potential applications in filters with high harmonic suppression and compact structures,

Analysis of profit models for cross-border power interconnection projects

With the increasing demand worldwide for power grid interconnection,a growing number of related projects are under planning or construction.Despite the rapid growth of cross-border interconnection projects,the systematic research on profit models for these projects is insufficient.This paper first analyzes the profit sources of interconnection projects.Based on the analysis results,profit models are considered under different regulatory systems for three types of crossborder interconnection projects:fully market-oriented,semi-marketization,and fully supervised.Finally,measures for increasing the profitability and sustainable development of power interconnection projects are proposed.

Miniaturized fractal-shaped branch-line coupler for dual-band applications based on composite right/left handed transmission lines

In this paper,novel dual-band (DB) branch-line couplers (BLCs) employing a composite right/left handed transmission line (CRLH TL) and fractal geometry are presented for the first time.The CRLH TL,with specified characteristic impedance and phase shift,consists of lumped elements for the left handed (LH) part and fractal-shaped microstrip lines (MLs) for the right handed (RH) part,which can be designed separately.Two designed BLCs are involved in size reduction,one using a 3/2 fractal curve of first iteration,the other constructed based on a hybrid shape of fractal and meandered lines.A miniaturized principle for CRLH TL realization is derived and an exact design method for fractal implementation is developed.For verification,an example coupler was fabricated and measured.Consistent numerical and experimental results confirmed the design concept,showing that the BLCs obtain DB behavior centered at 0.9 GHz and 1.8 GHz respectively with good in-band performance,except for slightly larger coupled insertion loss for the hybrid-shaped BLC case.In addition,the proposed fractal-and hybrid-shaped BLCs obtained a 49.7% and 64.1% size reduction respectively relative to their conventional counterparts working in the lower band.The most important contributions of this article are the demonstration of compatibility between the fractal and CRLH TL techniques and the provision of an alternative approach and a new concept for designing devices.

Harmonic suppressed bandpass filter using composite right/left handed transmission line

A wideband composite right/left handed transmission line (CRLH TL) in conjunction with its corresponding equivalent circuit model is studied based on a cascaded complementary single split ring resonator (CCSSRR).The characterization is performed by theory analysis,circuit simulation,and full-wave electromagnetic (EM) simulation.The negative refractive index (NRI) and backward wave propagation performance of the CRLH TL are demonstrated.For application,a bandpass filter (BPF) with enhanced out-of-band selectivity and harmonic suppression operating at the wireless local area network (WLAN) band is designed,fabricated,and measured by combining the CRLH TL with a complementary electric inductive-capacitive resonator (CELC).Three CELC cells with wideband stopband performance in the conductor strip and ground plane,respectively,are utilized in terms of single negative permeability.The design concept has been verified by the measurement data.

Tunable zeroth-order resonator based on a ferrite metamaterial structure

This paper proposes a tunable zeroth-order resonator on a composite right/left-handed transmission line consisting of a transversely magnetized ferrite substrate periodically loaded by microstrip inductors. Based on the propagation theory of edge guided modes, the analysis procedure of this structure is introduced. The numerical results demonstrate the tunability of the resonant frequency by changing the DC bias magnetic field applied to the ferrite. In contrast to previous work, the proposed structure is easy to design and fabricate and does not require a chip component.

Compact Multiband Patch Antenna Based on CRLH-TL Structures

A compact multiband patch antenna is designed by using HFSS in this work, which is filled with composite right/left-handed transmission line （CRLH-TL） structures. The simulated results reveal that the operating frequency becomes lower with left-handed （LH） characteristics of the CRLH-TL structures enhanced, which enable antenna physical size reduction to a large extent. The proposed antenna is fabricated on the substrate Rogers R03201 （relative permittivity of 10.2）, which has a compact size of 12 mm×12 mm × 4 mm. Moreover, this antenna exhibits monopole-like radiation pattern at one resonance frequency and patch-like radiation at the other four resonant frequencies. Therefore, the designed antenna is useful for communication systems.

Optimal portfolio design of energy storage devices with financial and physical right market

With the continuous development of the spot market,in the multi-stage power market environment with the day-ahead market and right market,the study associated with the portfolio of energy storage devices requires that attention should be paid to transmission congestion and power congestion.To maximize the profit of energy storage and avoid the imbalance of power supply and consumption and the risk of node price fluctuation caused by transmission congestion,this paper presents a portfolio strategy of energy storage devices with financial/physical contracts.First,the concepts of financial/physical transmission rights and financial/physical storage rights are proposed.Then,the portfolio models of financial contract and physical contract are established with the conditional value-at-risk to measure the risks.Finally,the portfolio models are verified through the test data of the Pennsylvania-New Jersey-Maryland(PJM)electric power spot market,and the comparison between the risk aversion of portfolios based on financial/physical contract with the portfolio of the market without rights.The simulation results show that the portfolio models proposed in this paper can effectively avoid the risk of market price fluctuations.