Complementary metamaterial transmission line for monoband and dual‐band bandpass filters application

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.     

Composite right/left handed artificial transmission line structures in CMOS for controlled insertion phase at 30 GHz

Two CMOS integrated circuits are presented that utilize metamaterial composite right/left handed (CRLH) transmission lines (TLs) for zero insertion phase at 30 GHz. Specifically, 2 and 3 unit cell structures are presented with controlled insertion phase that is achieved by cascading lumped element capacitors and spiral inductors in an LC network configuration defining the TL unit cells. Furthermore, the fixed TL structures suggest the possibility of zero, advanced or delayed insertion phases by element variation, or by the use of simple active components. Simulation and measured results are in good agreement with CRLH TL theory, and display a linear insertion phase and flat group delay values that are dependent on the number of unit cells with an insertion loss of ～0.8 dB per cell. These findings suggest that such high speed CRLH TLs structures can be implemented for linear array feeding networks and compact antenna designs in CMOS at millimeter wave frequencies. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009.     

Modal analysis of the microwave frequency response and composite right‐/left‐handed operation of a rectangular waveguide loaded with double positive and double negative materials

This article presents a theoretical study of the electromagnetic wave propagation in a rectangular waveguide, loaded with double positive (DPS) and double negative (DNG) dielectrics. The frequency response of the waveguide is analyzed using a modal technique. The results show that when at least one of the dielectrics is a DNG material the cutoff frequency of the waveguide is much more lower than the cutoff frequency of the DPS loaded or the empty waveguide. This interesting property means that very low frequency signals could be guided by structures that have very small size. Properties of composite right‐ and left‐handed wave propagation are also observed as well as the characteristic stop‐band between the frequency regions in which RH and LH wave propagation occurs. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.     

Compact meta-material transmission line balun based on meander lines structure and MEMS technology

This paper presents a novel compact meta-structure microstrip balun, which is characterized by left-handed properties. In the novel structure, two coupled meander lines are used to generate series capacitor and series inductor. Compared with conventional composite right/left-handed transmission-line structures, the new structure has smaller size and is easily fabricated by MEMS (Micro Electromechanical Systems) technology. Using such a meta-structure, a wide band microstrip balun is designed and fabricated. Good performance in phase error in wide pass band has been achieved.     

High‐efficiency leaky‐wave antenna with continuous wide‐angle scanning using hybrid composite right/left handed structure

A hybrid composite right/left handed (CRLH) structure based leaky‐wave antenna with continuous wide beam scanning is proposed in this article. Six series‐wound periodic units, combining spoof surface plasmon polariton (SSPP) with CRLH, form the radiating portion of proposed antenna. The unit is connected to the ground with metal hole, which provides the equivalent parallel inductance, and the unit is separated from its adjacent unit at prescheduled intervals, which provides the equivalent series capacitance. Additionally, the unit operates at balanced state and the open stopband is obviously suppressed. Dispersion diagram is also used to analyze this continuous scanning. A prototype of proposed antenna is fabricated and measured. The main beam of the antenna scans continuously from ?70° to +40° in the range from 5.2 to 8.8 GHz. The antenna radiation efficiency reaches a maximum of 92% in the working band. Measurement results agree quite well with the simulation, which indicate this leaky wave antenna can find potential applications in communication systems and radars.     

A CPW‐fed band notched wideband circularly polarized ZOR antenna based on CRLH‐TL approach

This article presents design and analysis of three wide band zeroth‐order resonance antennas (antennas I, II, and III) using composite right and left‐handed transmission line (CRLH‐TL) approach. Coplanar waveguide technology, single layer via‐less structures are used to have the design flexibility. The bandwidth characteristics are analyzed by using lumped parameters of CRLH‐TL. By introducing a simple slot in the ground plane of antenna I both bandwidth enhancement and circularly polarization characteristics are achieved in antenna II. Another quarter wave L‐shaped slot has been introduced in the ground plane of antenna II to introduce a notch band in the frequency response of antenna III. Achieved measured 10 dB return loss bandwidth of antenna I and antenna II are 960 (3.3‐4.26 GHz) and 2890 MHz (2.77‐5.66 GHz), respectively. Antenna III offers measured 10 dB return loss bandwidth of 3220 MHz (2.32‐5.54 GHz) with a band notch from 2.39 to 2.99 GHz that isolates the 2.4 GHz WLAN and 3.5 GHz WiMAX band. Antenna II and antenna III have circular polarization property with measured axial ratio bandwidth of 440 MHz. The measured peak realized gain of antennas II and III is around 1.53‐2.9 dBi.     

Low Phase Noise VCO using Novel Harmonic Control Circuit Based on Quad-band Composite Right/Left-handed Transmission Line

In this paper,a novel Voltage-Controlled Oscillator(VCO)using the harmonic control circuit based on the quad-band Composite Right/Left-Handed(CRLH)Transmission Line(TL)is presented to reduce the phase noise without the reduction of the frequency tuning range and miniaturizing the circuit size.The phase noise has been reduced by the quad-band harmonic control circuit which has the short impedance for the second-and third-and fourth-and fifth-harmonic components.The CRLH TL with two Left-Handed(LH)(backward)and two Right-Handed(RH)(forward)pass bands are used to design the quad-band harmonic control circuit.The high-Q resonator has been used to reduce the phase noise,but it has the problem of the frequency tuning range reduction.However,the frequency tuning range of the proposed VCO has not reduced because the phase noise has reduced without the high-Q resonator.The miniaturization of the circuit size is achieved by using the quad-band CRLH TL instead of the conventional RH TL.The phase noise of VCO is-124.43～-122.67 dBc/Hz at 100 kHz in the tuning range of 5.729～5.934 GHz.     

一种新型的左右手传输线超宽带滤波器

超宽带系统需要超宽带滤波器的相对带宽达到110%,并且使用常见的材料设计它,使其结构紧凑、价格便宜。该文将介绍用左右手传输线结构设计的新型超宽带滤波器。另外,利用微带线和共面波导相结合的方式来简化设计、缩小尺寸。其仿真结果证明了利用复合材料可产生负介电常数和负磁导率,滤波器在通带3.8到10.6GHz内的插入损耗小于1.0db。并且其中心频带附近的群时延约为0.20ns,这个群时延足够小,以至于它可以应用到无线通信系统中。     

Novel configuration of ultra‐wide band uni‐planar configuration of complementary split ring resonator composite right/left‐handed based band pass filter with sharp roll off and good stopband attenuation

In this paper, a compact novel simple design of ultra‐wide bandpass filter with high out of band attenuation is presented. The filter configuration is based on combining an ultra‐wide band composite right/left‐handed (CRLH) band pass filter (BPF) with simple uni‐planar configuration of complementary split ring resonator (UP‐CSRR). By integrating two UP‐CSRR cells, the ultra‐wideband CRLH filter roll‐off and wide stopband attenuation are enhanced. The filter has 3 dB cutoff frequencies at 3.1 GHz and 10.6 GHz with insertion loss equals 0.7 dB in average and minimum and maximum values of 0.48 dB and 1.05 dB, respectively over the filter passband. Within the passband. The transition band attenuation from 3 dB to 20 dB is achieved within the frequency band 1.9 GHz to 3.1 GHz (48%) at lower cutoff and the frequency band 10.6 GHz to 11.4 GHz (7%) at upper stopband. Moreover, the filter has a wide stopband attenuation >20 dB in frequencies 11 GHz to 13.6 GHz (21%) and ends with 3 dB cutoff frequency at 14.8 GHz. Furthermore, the designed filter size is very compact (23 × 12 mm²) whose length is only about 0.17 λ_g at 6.85 GHz. The filter performance is examined using circuit modeling, full‐wave simulations, and experimental measurements with good matching between all of them.     

Fully Printed Dual‐Band Power Divider Miniaturized by CRLH Phase‐Shift Lines

In this letter, a compact and fully printed composite right‐ and left‐handed (CRLH) dual‐band power divider is proposed. The branches of the conventional Wilkinson power divider are replaced by subwavelength CRLH phase‐shift lines having +90° for one frequency and ?90° for another frequency for dual‐band and miniaturization performance. Equations are derived for the even‐ and odd‐mode analysis combined with the dual‐band CRLH circuit. A PCS and a WLAN band are chosen as the test case and the circuit approach agrees with the CAD simulation and the measurement. Additionally, the CRLH property is shown with the dispersion diagram and the eightfold size reduction is noted.