A new defected ground structure (DGS) for the microstrip line is proposed in this paper. The DGS unit can provide bandgap characteristic some frequency bands with only one or more lattices. equivalent circuit derived by means of three-dimensional field analysis methods. equivalent-circuit parameters are extracted using a simple method. By employing and theory, effect provided be explained. parameters, low-pass filters designed implemented. experimental results show excellent agreement...

Metamaterials are artificial structures that can be designed to exhibit specific electromagnetic properties not commonly found in nature. Recently, metamaterials with simultaneously negative permittivity (/spl epsiv/) and permeability (μ), more referred as left-handed (LH) materials, have received substantial attention the scientific engineering communities. The unique of LHMs allowed novel applications, concepts, devices developed. In this article, fundamental physical realization these...

This paper presents a novel photonic bandgap (PBG) structure for microwave integrated circuits. new PBG is two-dimensional square lattice with each element consisting of metal pad and four connecting branches. Experimental results microstrip on substrate the PEG ground plane displays broad stopband, as predicted by finite-difference time-domain simulations. Due to slow-wave effect generated this unique structure, period only 0.1/spl lambda//sub 0/ at cutoff frequency, resulting in most...

A new two-dimensional (2-D) photonic bandgap (PBG) structure for microstrip lines is proposed, in which a periodic 2-D pattern consisting of circles etched the ground plane line. No drilling through substrate required. Three PBG circuits were fabricated with different circle radii to determine optimum dimensions, as well circuit compensated right-angle bend. Measurements show that deep and wide stopbands can be achieved using this method.

A simple method for formulating the dyadic Green's functions in spectral domain is presented generalized printed transmission Iines which contain several dielectric layers and conductors appearing at interfaces. The based on transverse equivalent line a wave coordinate transformation. This formulation process so that often it accomplished almost by inspection of physical cross-sectional structure line. applied to new versatile line, microstrip-slot Iine, some numerical results are presented.

Left-handed (LH) materials, first introduced theoretically in Veselago (1968), have spurred considerable excitement since the demonstration of their practical realizability. The unique properties these metamaterials, verified by full-wave analysis Caloz et al. (2001), are promising for a diversity optical/microwave applications, such as new types beam steerers, modulators, band-pass filters, superlenses, microwave couplers and antenna radomes. However, LH structures presented so far...

A novel dominant mode leaky-wave antenna is proposed. This a transmission line structure with radiating wavenumber increasing from negative to positive values, providing backward forward scanning capability as frequency increased. The characteristics and performances of the are demonstrated by full-wave simulation measurement results.

A novel composite right-/left-handed (CRLH) backward-wave coupled-line directional coupler with arbitrary coupling level and broad bandwidth is presented, explained by even/odd-mode analysis, validated full-wave simulations, demonstrated experiments. First, the CRLH-transmission-line (CRLH TL) theory given, a microstrip implementation of CRLH TL described. simple circuit model then proposed both for understanding design coupler. The exhibits very unusual characteristics, such as zero...

A transmission line (TL) approach of left-handed (LH) materials is proposed. The characteristics an ideal LH-TL are presented, the constitutive parameters equivalent LH material derived and shown to be negative, some LH-transmission paradoxes explained. Next, a method design artificial in form lumped-elements ladder network described illustrated with simulation results. It that, this line, left-handedness can achieved without losses over unlimited bandwidth, from cutoff resulting high-pass...

Arbitrary dual-band microstrip components using composite right/left-handed (CRLH) transmission lines (TLs) are presented. Theory, synthesis procedure, and implementation of the quarter-wave (/spl lambda//4) CRLH TL operation is achieved by frequency offset phase slope TL. The ratio two operating frequencies can be a noninteger. /spl lambda//4 open/short-circuit stub, branch-line coupler (BLC), rat-race (RRC) also demonstrated. performances these demonstrated both simulated measured results....

The recently developed uniplanar compact photonic bandgap (UC-PBG) substrate is successfully used to reduce surface-wave losses for an aperture-coupled fed patch antenna on a thick high dielectric-constant substrate. dispersion diagram of the UC-PBG has been numerically computed two different thickness (25 and 50 mil) found have complete stopband in frequency range 10.9-13.5 11.4-12.8 GHz, respectively. thicker then enhance broadside gain working at 12 GHz. Computed results measured data...

A metamaterial-based electronically controlled transmission-line structure is presented and demonstrated as a novel leaky-wave (LW) antenna with tunable radiation angle beamwidth functionalities. This is, in essence, composite right/left-handed (CRLH) microstrip incorporating varactor diodes for fixed-frequency voltage-controlled operation. Angle scanning at fixed frequency achieved by modulating the capacitances of adjusting (uniform) bias voltage applied to varactors. Beamwidth tuning...

This paper provide a review of the active integrated antenna (AIA) technologies. After brief introduction on definition and some historical remarks, concentrates research effort past decades or so. The AlAs are reviewed in its various functions. First, an oscillator-type AIA is presented, followed by very interesting aspects coupled oscillator arrays for phase control. Use concept efficient RF front ends described with examples high-power amplifier AlAs. Next, phase-conjugation-based...

The boundary value problem associated with the open microstrip line structure is formulated in terms of a rigorous, hybird-mode representation. resulting equations are subsequently transformed, via application Galerkin's method spectral domain, to yield characteristic equation for dispersion properties line. Numerical results included several different structural parameters. These compared other available data and some experimental measurements.

The analysis of resonant-type antennas based on the fundamental infinite wavelength supported by certain periodic structures is presented. Since phase shift zero for a unit-cell that supports an wavelength, physical size antenna can be arbitrary; antenna's independent resonance phenomenon. operational frequency depends only its and number unit-cells. In particular, composite right/left-handed (CRLH) metamaterial transmission line (TL). It shown CRLH TL general model required unit-cell, which...

Metamaterials are materials typically engineered with novel or artificial structures to produce electromagnetic properties that unusual difficult obtain in nature. Because of their promise provide engineerable permittivity, permeability, and index refraction, metamaterials have drawn broad interest led possible utilization many applications from the microwave optical regime, especially for radiated-wave devices. This paper presents a detailed review upon most recent research efforts...

A novel broadband planar antenna based on the classic Yagi-Uda dipole array is presented. This "quasi-Yagi" achieves a measured 48% bandwidth for VSWR <2, better than 12 dB front-to-back ratio, smaller -15 cross polarization, 3-5 absolute gain and nominal efficiency of 93% across operating bandwidth. Finite-difference time-domain simulation used optimization results agree very well with measurements. Additionally, gain-enhanced design presented, where higher has been achieved at cost reduced...

The composite right/left-handed (CRLH) transmission line (TL) is presented as a general TL possessing both left-handed (LH) and right-handed (RH) natures. dispersion diagram of the two-dimensional (2-D) CRLH-TL obtained analytically based on Bloch-Floquet theory, unique phenomenon infinite guided-wavelength propagation, with nonzero group velocity at frequency, explained. It shown that when CRLH "balanced", two eigenfrequencies /spl Gamma/ point (/spl beta/=0) Brillouin zone (BZ) degenerate...

A substrate integrated waveguide with square complementary split-ring resonators (CSRRs) etched on the surface is investigated in this paper. The proposed structures allow implementation of a forward-wave passband propagating below characteristic cutoff frequency waveguide. By changing orientations CSRRs, which are incorporated and can be interpreted terms electric dipoles, varied characteristics observed. detailed explanation for generation variations passbands has been illuminated....

Composite right-/left-handed (CRLH) transmission-line (TL) metamaterials, with their rich dispersion and fundamental right-/left-hand duality, represent a paradigm shift in electromagnetics engineering and, particular, for antennas. This paper presents an overview of the most practical leaky-wave resonant CRLH antennas, which all exhibit functionalities or/and performance superior to prior state art. The antennas provide full-space dynamic scanning capability, fan beams, conical beams...

An investigation into the design of compact patch antennas loaded with complementary split-ring resonators (CSRRs) and reactive impedance surface (RIS) is presented in this study. The CSRR incorporated on as a shunt LC resonator providing low resonance frequency RIS realized using two-dimensional metallic patches printed metal-grounded substrate. Both meta-resonator (CSRR) meta-surface are able to miniaturize antenna size. By changing configuration CSRRs, multi-band operation varied...

Composite right/left-handed (CRLH) substrate integrated waveguide (SIW) and half mode (HMSIW) leaky-wave structures for antenna applications are proposed investigated. Their propagation properties radiation characteristics studied extensively. backfire-to-endfire beam-steering capabilities through frequency scanning demonstrated discussed. These metamaterial radiating realized by etching interdigital slots on the surface ground. The slot behaves as a series capacitor well radiator leading to...

In this paper, a novel broadband planar antenna based on the classic Yagi-Uda dipole is presented, and its usefulness as an array explored. This "quasi-Yagi" realized high dielectric-constant substrate, completely compatible with microstrip circuitry solid-state devices. achieves measured 48% frequency bandwidth for voltage standing-wave ratio <2, better than 12-dB front-to-back ratio, smaller -15 dB cross polarization, 3-5-dBi absolute gain. Mutual coupling of in environment investigated....