Full wave modeling of microstrip via holes

A rigorous full-wave analysis of microstrip via hole grounds is performed using a three-dimensional mode-matching method associated with a suitable segmentation technique. Theoretical results are compared with measured data showing excellent agreement.     

Modal expansion method of analysis for slot-coupled microstrip antenna

A modal field expansion technique together with the Poynting theorem are used to derive the input impedance of a slot-coupled microstrip antenna. The approach leads to easier and lower computational requirements. Predicted values of input impedance are compared with previous theoretical and experimental results.<>     

A full-wave analysis method for open microstrip structures

A method for analyzing characterisitcs of open microstrip disk structures is presented. The method is based on the spectral domain immittance matrix approach, and all the wave phenomena associated with the structures are incorporated. The method provides a number of unique and convenient features both in analytical and numerical phases. A numerical example illustrating the usefulness of the method is included. Some numerical results are compared with experimental data.     

A modal expansion method of analysis and measurement onaperture-coupled microstrip antenna

The coupling of a feedline to a rectangular patch through an aperture in the ground plane separating them is described using modal field analysis. The cavity model is used to describe the patch, the feedline is represented by a dynamic planar waveguide model, and the coupling is via a magnetic current in the aperture. Both theoretical and experimental results for the antenna performance are presented and design curves are generated. Very good agreement between theory and experiment was obtained. Results and design curves were obtained for antennas at 5 and 10 GHz, respectively     

Aperture-coupled microstrip line leaky wave antenna with broadsidemainbeam

A microstrip first higher order leaky wave antenna (LWA), centre-fed by an aperture-coupled microstrip with a broadside mainbeam, is presented. The measured bandwidth (23% for VSWR<2:1) is in agreement with the leaky radiation band predicted. The experimental gain patterns, compared with those of a patch antenna fed by the same type of structure, reveal the difference between these two kinds of antenna. With increasing frequency, the radiation field of the LWA spreads into the H-plane, forming a flatter broadside pattern, which can be applied to long rectangular area communication     

基于FDTD的微带漏波天线分析的新方法

使用时域有限差分法对微带漏波天线进行数值仿真,得到了微带漏波天线TE01模下的电场分布,对微带漏波天线的电波传播特性进行初步的讨论.提出新的经验计算公式微带漏波天线漏波传播系数,所得漏波传播系数曲线与实测数据以及比较数据十分吻合.     

Transmission line analysis of aperture-coupled microstrip antenna

The authors present an original analysis of a slot-coupled microstrip antenna. The transmission line model uses previous expressions of conductance and susceptance due to the fringing fields near the edges of the patch; moreover, a simple interpretation of the different impedance transformations is given. Results based on the transmission line model are compared with other theoretical analyses (cavity model, moment method) and measurements.<>     

周期加载微带结构的模式分析

周期性的微带结构在相控阵天线、频率选择表面等领域都有着广泛应用。与单纯的接地介质板相比，它的电磁波模式更为复杂，解析式几乎不可得到。文中利用格林函数和矩量法相结合，对无限大的微带周期结构的表面波和漏波特性进行了数值分析，计算了方形环和方形贴片阵列两种情况。电流展开采用了分域基函数，计算得到了它的表面波和漏波模式的传播常数。     

耦合微带线设计的一种实用方法

本文根据耦合微带线的某些特性,提出了耦合微带线设计的一种实用方法.     

An analysis of millimeter wave quasi-optical gaussian beam radiation-perturbational expansion method

In this paper perturbational expansion of wave equation is used to analyse the Gaussian beam radiation efficiency and the near field distribution of aperture antenna. The analysis is also suitable at large angles from boresight because the Gaussian beam used here is corrected to satisfy wave equation. An approach of minimum deviation of aperture field is used to calculate the Gaussian beam radiation efficiency, and calculation results is compared with that of Wydle's[1].     

NAM expansion method for systematic synthesis of OTA-based floating gyrators

This paper presents a NAM expansion method for systematically synthesizing OTA-based floating gyrators. After describing nullor-mirror components of OTAs, class I, II and III gyrators, which can be built with standard OTAs, are synthesized by using the nullor-mirror equivalent models described by NAM. The class-I gyrators employing two DO-OTAs have four equivalent realizations, the class-II gyrators employing three SO-OTAs have eight equivalent realizations, and the class-III gyrators employing four SISO-OTAs have 16 equivalent realizations. Having used canonic number of components, the circuits are easy to be integrated and their parameters can be tuned electronically through tuning bias currents of OTAs. Finally, as an example, the MULTISIM simulation results of a notch filter constructed by the OTA-based III gyrator are presented to verify the realizability of the derived circuits.     

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.<>     

Ring-resonator method - effective procedure for investigation of microstrip line

In addition to the traditional application of the ring-resonator method for determination of the microstrip line effective permittivity, measurements of the insertion losses and equivalent substrate permittivity are proposed. The obtained data for a number of isotropic and anisotropic substrate materials are in good agreement with the results predicted theoretically.     

Numerical analysis of surface wave on microstrip antenna with lossysubstrate

The key to analysing a guided surface wave is to solve its eigenvalue equation. When the medium is dissipative, the eigenvalue equation is a complex transcendental equation. The Kuhn algorithm is applied to work out the eigenvalue equation     

A method for designing broad-band microstrip antennas inmultilayered planar structures

The narrow bandwidth of a microstrip antenna is one of the important features that restrict its wide usage. A simple and practical method for the design of broad-band microstrip antennas is presented in this paper. Utilizing this design technique, several two-layer microstrip antennas have been proposed. To confirm the applicability of the method for the designs of antennas at L-band, experiments have been carried out. The measured results show that the proposed antennas have a bandwidth of up to 25.7%. Also, the method proposed in this paper is applicable to the design of other types of multilayered planar antennas     

Time-domain Green's functions for microstrip structures using Cagniard-de hoop method

Time-domain Green's functions are required for transient analyzes of many structures using the time-domain integral equation method. In this paper, we express the generalized reflection coefficient of the microstrip structure in terms of a geometric optics series so that by applying the Cagniard-de Hoop method to each term of the series, we can derive the time-domain Green's function. It is demonstrated that this series converges rapidly and there are two contributing waves from each source image if the observation point is beyond the total internal refraction location. The two waves are the direct wave from the image and the head wave from the image to the critical point, and then laterally along the surface to the observer. Each contribution is a definite integral that is evaluated for each point in space and time. Therefore, the derived Green's function is efficient for time-domain simulations compared with conventional approach, in which for each point in space and frequency a Sommerfeld type integral is involved and then the frequency-domain data is converted into time-domain by discrete Fourier transform. This rigorous Green's function can also be used to check the accuracy of other approximate methods such as those using the discrete complex image theory.     

Transient analysis of microstrip line on anisotropic substrate inthree-dimensional space

The authors describe how anisotropy, with the permittivity tensor involving off-diagonal elements, may be generally formulated by Bergeron's method. The formulation is discussed for the propagation characteristics of single and parallel striplines on a sapphire substrate with tilted optical axis. To show the distinctive influence of anisotropy on the coupling property between lines, a parallel-line-type directional coupler on such a substrate is analyzed     

Analysis of shielded membrane microstrip line using the finite-difference time-domain method

A simple and efficient analysis method of the shielded membrane microstrip (SMM) line using the finite-difference time-domain (FDTD) method is presented. New FDTD equations are derived using the contour path FDTD concept for the Yee cell which contains three thin dielectric sheets of membrane. The characteristic impedance and the effective dielectric constant of the SMM line are calculated using our proposed method. The method is validated by comparison with the results shown by Robertson et al. [1996].