Evaluation of closed-form crosstalk models of coupled transmissionlines

Closed-form crosstalk models used for the estimation of near and far end crosstalk voltages between two parallel transmission lines are evaluated. The quantitative validity ranges, in terms of transmission line length and coupling strength, of the crosstalk models are presented. It is shown that the accuracy of the commonly used closed-form crosstalk models deteriorates as the increase of the coupling strength and the line length     

The incremental inductance rule in quasi-TEM coupled transmissionlines

The application of the incremental inductance rule is described for the computation of losses in quasi-TEM coupled transmission lines. It is shown that the well-known formula valid for the single-line case can be extended to the case of normal modes travelling in general coupled structures providing one uses the power-current modal characteristic impedance definition. Numerical results are shown for several coupled lines systems     

Even mode analysis of symmetric coupled microstrip

The analysis formula of Garg and Bahl for computation of the even mode impedance of a symmetric coupled microstrip line is replaced by another algorithm which shows better agreement with Bryant and Weiss data.     

Transmission line analysis of nonlinear slot coupled microstrip antenna

The transmission line method is used for the analysis of microstrip antennas fed by several nonlinear slots with 'H' shapes or new geometries. This analysis allows the input impedance of nonlinear slot coupled microstrip antennas to be calculated for the four different structures.<>     

Electromagnetically coupled microstrip dipoles

A new class of printed circuit radiator consisting of a microstrip dipole electromagnetically coupled to a microstrip feed line is described. Several configurations which differ in bandwidth, efficiency, and construction simplicity are presented. A geometry which has been found to be optimum for many applications is noted. Radiation characteristics of both isolated elements and arrays of elements are examined. Experimental and theoretical results are presented.     

Complete and rigorous analysis of electromagnetically coupled transverse microstrip dipole

A rigorous and complete analysis of the electromagnetically coupled transverse microstrip dipole is presented. This new feeding process offers an alternative solution, which is especially interesting when it is necessary to excite several dipoles from the same line. The theoretical results are compared to experimental measurements in X-band for the input impedance and the radiation patterns (co- and crosspolarisation).     

Spectral domain analysis of coupled microstrip lines on magnetized ferrite substrates

Dispersion characteristics of coupled microstrip lines on ferrimagnetic substrates are presented and their features discussed. The Hertz vector potentials in the spectral domain method are used to calculate the dyadic Green's functions in an impedance matrix form. The behavior of the propagation constants is obtained by using the spectral Galerkin's technique. Numerical results are found as a function of various geometrical parameters and of the externally applied static magnetic field. Nonreciprocal behavior is mainly observed when the static magnetic field is applied in the transverse direction, parallel to the ground plane.     

Two-port active coupled microstrip antenna

A multilayer structure, based on a patch antenna coupled through a nonresonant slot to a pair of feeding microstrips is a versatile module which can be used as a radiating and resonating element in a number of different configurations. Direct connection to a low cost transistor in a feedback loop results in a very simple active antenna, as reported. Different termination conditions at the four microstrip ports give rise to a number of alternative configurations for active generation/detection and multipatch arrays.<>     

Broad-band gap coupled microstrip antenna

A microstrip antenna with large bandwidth is developed using a parasitic technique. Compared to the available wideband antennas, the proposed antenna structure is very compact and gives a less distorted radiation pattern with frequency. An impedance bandwidth eight times that of a conventional patch antenna of the same size is achieved. The concept of coupled microstrip line model is extended for theoretical interpretation of the impedance loci. The experimental procedure and results are described, and a theoretical analysis is presented     

Circularly polarised aperture coupled microstrip antenna

The orthogonal mode of an aperture coupled rectangular microstrip antenna can be coupled to the aperture-excited mode with coplanar microstrip lines to provide a compact circularly polarised element with a single aperture feed. An equivalent circuit model was developed for the analysis and design of this element, and a working version was used to demonstrate the concept. The features of this antenna are compared with several other circularly polarised microstrip antennas     

Matched coupled microstrip transistor amplifier methodology

In this paper, we present a generalized methodology for synthesizing narrowband amplifiers in coupled microstrip systems and detail a novel narrowband amplifier in a three-coupled microstrip topology utilizing chip capacitors for matching networks. The purpose of such a configuration is to validate the synthesis of microwave amplifiers in coupled microstrip technology (the ground plane being common to many fabrication technologies) where the planarity inherent to coplanar designs alleviates the need for vias, thereby reducing fabrication cost.     

Aperture coupled microstrip antenna element design

Aperture coupling is investigated as a feed mechanism for microstrip antenna elements. Using modal field expansion, and assuming that coupling is via a magnetic current in the aperture, calculated data on the antenna parameters are obtained. Several samples are manufactured, tested and practical design curves generated at 5.0 and 10 GHz. Good agreement between theory and experiment is obtained. These new results extend the validity of the analysis at high frequencies and will be useful for design and applications involving this type of antenna.<>     

Analysis of an aperture coupled microstrip antenna

A microstrip patch antenna that is coupled to a microstripline by an aperture in the intervening ground plane is analyzed. Coupled integral equations are formulated by using the Green's functions for grounded dielectric slabs so that the analysis includes all coupling effects and the radiation and surface wave effects of both substrates. A Galerkin moment method solution of the coupled integral equations agrees quite well with measured data. Design data are contained in parameter studies, many of which are verified by experimental results.     

Analysis of microstripline coupled to microstrip antenna

An analytical method based on the aperture coupling theory and S-parameter matrix has been developed for modelling a microstripline coupled to a microstrip antenna using a circular coupling aperture. The theoretical results agree fairly well with the measurements. The analysis should have many applications in active array developments.     

微带交叉耦合滤波器的简化设计

主要研究微带交叉耦合滤波器的简化设计。通过约束传输零点之间的关系,简化了带通滤波器交差耦合的拓扑结构,同时又较好保持了带通滤波器带外的抑制能力。在利用微带结构实现时,采用了谐振器顺序耦合的结构,降低了滤波器微调的难度。同时在第一和第四谐振器间增加一段传输线以引入交叉耦合,通过调整引入传输线的位置等可调整相应传输零点的位置,增加了滤波器设计的灵活性。仿真结果验证了相关方法的有效性。     

Computer analysis of the fundamental and higher-order modes in single and coupled microstrip

By means of finite-difference methods, dispersion curves are obtained for the fundamental and higher-order hybrid modes in both single and coupled microstrip. Structures of realistic proportions are investigated by the use of a graded finite-difference mesh. Variational methods are used in deriving the finite-difference equations.     

Problem-matched basis functions for microstrip coupled slot arrays based on transmission line Green's functions (TLGF)

Problem matched basis functions are proposed for the method of moments analysis of printed slot coupled microstrips. The appropriate equivalent currents of the integral equation kernel are represented in terms of two sets of entire domain basis functions. These functions synthesize on one hand the resonant behavior of slots, microstrips or dipoles and on the other hand the field in proximity of the feeding source and of the discontinuities. In order to define these basis functions, canonical geometries are identified, whose Green's functions have been found in semi-analytical form. The accuracy and the effectiveness of the method in terms of convergence rate and number of unknowns is demonstrated by comparison with a standard fine meshing full-wave analysis. The method is extremely convenient for large arrays, where the subwavelength details should be treated together with large global dimensions. Since the proposed solution is independent of the dimensions of these details, it provides dramatic reduction of the number of unknowns and improvement of condition number.     

A new aperture coupled microstrip slot antenna

A new aperture coupled design is proposed for microstrip slot antennas to improve their radiation performance. The proposed design is based on a new aperture coupling technique in which the slot is fed by a microstrip line and coupled to several parasitic patch radiators etched on the opposite side from the slot. In contrast to the combination of a slot and a microstrip patch in conventional aperture coupled microstrip antennas, the patches here are employed to reduce the radiation into the half-space that they occupy and increase the radiation in the other half-space. Therefore, the slot antenna can produce radiation patterns with a high front-back ratio. The above objective is achieved by optimizing standing wave distributions of the aperture electric field in the slot through the adjustment of the position of the patches along the axis of the slot. In this paper, design considerations are given, and the results are validated by numerical simulations and experimental measurements.     

Directly coupled multiple resonator wide-band microstrip antennas

Three new configurations for increasing the impedance bandwidth of the microstrip patch antennas are described. In these configurations, additional resonators are directly coupled through short sections of microstrip line to the radiating edges, nonradiating edges, and all the four edges of the rectangular patch antennas, respectively. Green's function approach and segmentation method are used for the analysis. The experimental results are in reasonable agreement with the analysis and impedance bandwidths of 548 MHz, 605 MHz, and 810 MHz are obtained for these three configurations, respectively inS-band (substrate thickness = 0.318 cm andepsilon_{r} = 2.55). The variation in the radiation pattern over this impedance bandwidth is discussed.     

Pulse distortion on multilayer coupled microstrip lines

The distortion of pulses due to dispersion and coupling on generalized planar microstrip is investigated. A simple, general form for the Green's function is obtained by solving the boundary value problem separately for the TE and TM modes. The mechanism of even/odd-mode distortion is discussed and numerical results are presented illustrating its effect. The design of structures with low even/odd-mode distortion is considered. Results for pulse distortion on this type of microstrip are also included