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Proposed in this paper is a new configuration for a quad-band antenna based on using a metamaterial-inspired defected ground structure. The presented structure is introduced as a new modified metamaterial Complementary Split Ring Resonator (CSRR) with a compact electrical size. The new modified CSRR has been employed in Composite Right/Left-Handed (CRLH) transmission line configuration for ultra-size reduction. Validation for the particle small size is introduced and the detailed analysis for the NRI characteristics has been discussed by extracting the cell constitutive parameters. Hence, a multi-band antenna is designed based on using only one cell of the proposed NRI-TL. Subsequently, a small multi-band antenna is presented for different multi-band functionalities and different radiation properties. The antenna displays quad-resonances at 1.78 GHz, with the typical omnidirectional radiation pattern, 3.28 GHz, 4 GHz, and 4.3 GHz, with the directive broadside radiation properties. The proposed antenna footprint is 10 × 10 cm2, which exhibits a size reduction of up to 80% in comparison with a rectangular patch antenna operating at the lowest frequency band. [ABSTRACT FROM AUTHOR]

This article introduces analysis of the new configuration; inductor loaded left‐handed composite right‐/left‐handed transmission line ((L‐CRLH TL). Compared to conventional CRLH and dual CRLH, this configuration has the advantage of very slow phase (almost constant) and nonlinear propagation coefficient which enables it to be very effective in designing compact size and ultra‐wideband (UWB) microwave components. The theoretical and circuit model of the L‐CRLH TL is discussed. As an application, a compact UWB (3.1‐10.6 GHz) L‐CRLH power divider is designed using only one L‐CRLH cell with size of 2.7 × 8.6 mm2 whereas the whole power divider photoprint is 12.14 × 18.83 mm2. The size is 58.5% smaller compared to the conventional narrow band T‐junction power divider designed at the mid frequency. The results reveal good insertion losses (3.2 ± 0.2 dB for both S21 and S31), and good return losses (better than 10 dB within the passband). [ABSTRACT FROM AUTHOR]

A small size and wide-band band pass filter with high performance for WiMAX applications is introduced. The filter is designed by utilizing one composite right left handed transmission line (CRLHTL) metamaterial cell and two gap lumped capacitors. The filter has a center frequency of 5.3 GHz and a 3dB bandwidth from 4.2 GHz to 6.4 GHz. A lower than 0.5 dB insertion loss within pass-band is achieved. A single transmission zero at 6.52 GHz is achieved to increase the selectivity of the proposed filter. The rejection band is extended to be up to 10 GHz. A comparison between circuit simulation, EM simulation and measured results is introduced with good consistency between them. The filter has a small size (26.8 × 16.5 mm2) which is smaller than recently reported wide band filters. [ABSTRACT FROM AUTHOR]

Abstract This paper presents the experimental verification of the tunable characteristics of a ferrite composite right/left handed coupled line coupler. The coupler is designed using two coupled CRLH-CRLH transmission lines. The coupler is designed to demonstrate equal through and backward coupling. The novel coupler has been designed and realized in coplanar waveguide configuration on a ferrite substrate. The tunable characteristics are achieved by changing the applied DC magnetic bias to the ferrite substrate. The measurement results reveal that the coupler's fractional bandwidth can be tuned from 29% to 69% by varying the applied DC magnetic bias from 1000 Oe to 1750 Oe. Within the tunable bandwidth, the maximum backward coupling is −5 dB. The coupler has high forward coupling isolation, close to −30 dB at its centre operating frequency. In addition to its tuning capability, the coupler has the advantages of its compact size; it has the length of 11.5 mm and not-so-tight line separations of 2.5 mm. Furthermore the coupler only requires low DC magnetic bias. [ABSTRACT FROM AUTHOR]

This article presents a new small size dual band metamaterial antenna. The antenna is realized using a single cell of a suggested modified version of composite right left handed transmission line terminated by a hybrid capacitive loading with short circuit termination. The hybrid termination leads to decrease the size of the antenna whereas the modified composite right left handed cell configuration leads to introduce dual band antenna functionality at 2.5 and 2.92 GHz. The antenna size is only 31 × 26 mm2. Compared to, single band, non-selective, conventional patch antenna, the size of the proposed antenna is only 9 and 11.5% at the two former frequencies, respectively. Despite the small size, the antenna gain is more than 3.5 dBi at the two operating frequencies. Moreover, the antenna has a high roll off beyond the operating frequency band which leads to high selective characteristics. The antenna can suppress 100% of the nearby signal power beyond its bands by 300 MHz at lower band and 200 MHz at upper band. The antenna design is discussed; the full wave simulation and experimental measurements are introduced for validating the results. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a compact dual-band two-element array antenna in a substrate integrated waveguide (SIW) configuration for C-band applications. A new geometry based on an asymmetric composite right–left-handed transmission line cells was suggested for the single antenna element. The proposed geometry has the advantage of having arbitrary dual-frequency design. The array elements are fed with a wideband SIW impedance transformer. The results indicate that the proposed antenna element size is only 15 × 12.8 mm2, which approximately represents up to 70% size reduction at similar frequencies. The radiation properties of the array antenna have broadside radiation pattern at the two bands. The detailed analytical design explanation, full wave simulations, and experimental measurements are introduced. [ABSTRACT FROM AUTHOR]

The theoretical study and experimental results of a compact tunable left-handed (LH) zeroth order metamaterial ferrite resonator is presented. The resonator has been designed and realised using a LH coplanar waveguide transmission line on a ferrite substrate. The theoretical analysis of the operation principles of the resonator has been provided. The detailed measurement setup and experimental results are discussed. The resonator is only 0.19 λg (65% reduced in size comparing with conventional one) at 4 GHz. The resonator has fractional bandwidth of 0.1% and average insertion loss, approximately 4.5 dB. Moreover, the zeroth order metamaterial ferrite resonator has tuning capability and requires lower DC magnetic bias. [ABSTRACT FROM AUTHOR]

In this study, the authors present a novel compact non-reciprocal ferrite forward composite right-/left-handed (CRLH) coupled-line coupler (CLC). The proposed forward coupler is realised in coplanar waveguide configuration using series air gap capacitors and shunt planar segment inductors. A theoretical coupled mode analysis of a general non-ferrite CRLH forward CLC has been proposed. The mode analysis is then extended to ferrite CRLH forward CLC. The ferrite coupler's performance has been further analysed numerically and verified experimentally. Both numerical and experimental results have shown that the coupler demonstrates non-reciprocal operation for both forward coupling and through propagations. The coupler can achieve ~10 dB forward coupling and through levels with nonreciprocity isolation up to 30 dB. Moreover, the coupler has high backward coupling isolation better than 20 dB and very compact size with coupling length = 0.08 λ0 or (0.2 λg) at 8 GHz which is significantly smaller compared with any forward coupler reported to date in the similar operating frequency bands. Although, a conventional ferrite forward CLC can be non-reciprocal, it has long length, resulting in very high losses. This is not the case for the proposed CRLH coupler. Hence, the novelty and advantage of the coupler are its combined properties in compactness and nonreciprocity. Furthermore, the coupler requires very low external DC magnetic bias because of its much lower demagnetisation compared with the microstrip configuration. [ABSTRACT FROM AUTHOR]

This paper presents an ultra compact dual-band coplanar waveguide metamaterial filter based on generalized metamaterial transmission line. The detailed theoretical design steps of the filter are explained. The dual-band filter design performance has been validated using equivalent circuit modeling, electromagnetic full wave simulations, and practical measurement. The results illustrate the filter has dual passbands centered at 0.82 and 1.48 GHz with approximately 1 dB insertion loss and minimum 12 dB return loss. Good agreements between the circuit modeling, electromagnetic full wave simulations, and practical measurements are achieved. Moreover, the filter size is only (18 × 28 mm2) which is only less than (0.2λg × 0.31λg) at the center frequency of the first passband and (0.36λg × 0.56λg) at the center frequency of the second passband. [ABSTRACT FROM PUBLISHER]

In this paper, a novel compact and tunable impedance transmission line transformer is presented for the first time. The transformer is designed using a left handed coplanar waveguide transmission line on a ferrite substrate. Based on the dispersive properties of the ferrite medium, the theoretical study of the transformer has been carried out using its equivalent circuit analysis and the composite right / left handed transmission line theory. The theoretical study was verified through full wave electromagnetic numerical simulations. The results show that the transformer matches a 25 Ω load to a 50 Ω line with tunability from 2.55 GHz to 3.2 GHz. The return loss at center frequency is better than 20 dB with insertion loss better than -1 dB. The transformer has a very compact size with dimensions of 4.25 × 21 mm, showing approximately 64% reduction in size in comparison with a conventional right-handed transformer within the same operating frequency band. Moreover, the proposed coplanar waveguide transformer configuration has smaller demagnetization factor and hence it requires smaller DC magnetic bias values compared to microstrip configuration. [ABSTRACT FROM AUTHOR]

A novel ferrite nonreciprocal left-handed (LH) transmission line is presented. The proposed structure is composed of a coplanar waveguide over a ferrite substrate, horizontally magnetized and periodically loaded with only shunt inductors. The line has a nonreciprocal LH propagation with transmission level better than -5 dB with isolation level up to 20 dB over a moderate bandwidth. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2810–2814, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22848 [ABSTRACT FROM AUTHOR]

This article introduces a new design and analysis of a compact reconfigurable bandpass/lowpass filter based on compact negative refractive index metamaterial transmission line. The filter equivalent circuit has been designed as a cascade of three cells of bisected‐Π/Π configuration. The reconfigurable function was achieved using inserted switches in ON and OFF modes within the cells. The filter works as bandpass when all switches are in ON condition and for lowpass switch‐1 is in OFF and switch‐2 in ON condition. The low pass filter has 3‐dB cutoff frequency of 3.25 GHz with a selectivity of 170 dB/GHz. The bandpass filter is cantered at 3.65 GHz and has a well‐matched pass band with insertion loss of 0.2 dB and wide stop band with two transmission zeros (TZs). The frequency positions of TZs are independently varying with series and shunt loading elements. The filter performance has been validated through circuit model, electromagnetic simulation, and experimental measurements. The electrical size of bandpass filter excluding feed line is 0.22 λg × 0.20 λg (12 × 11 mm2) at center frequency of 3.65 GHz and for lowpass filter is 0.19 λg × 0.18 λg at cutoff frequency of 3.25 GHz. The filter can be applied in suitable for different wireless applications. [ABSTRACT FROM AUTHOR]