Multilayer Microstrip Structure Research Articles

Compact Half-Mode SIW Filter With High Selectivity and Improved Stopband Performance

In this letter, a novel filter with high selectivity is proposed using a hybrid multilayer half-mode substrate-integrated waveguide (HMSIW). First, a rectangular HMSIW is used to realize a third-order cross-coupling topology, which could introduce a transmission zero (TZ) on the left side of the passband. Then a ring microstrip resonator is added to form the new dangling block, which realizes the fourth-order response with an additional TZ located on the right side of the passband. Sharp skirt and high selectivity are then achieved. In addition, since each mode of the HMSIW has different external coupling strengths at the same feeding position, harmonic suppression can be achieved easily by moving the feeding position. Therefore, a good stopband can be obtained with decent out-of-band performance. Size reduction is also achieved through the multilayer HMSIW and hybrid microstrip structures as well.

Switched-Beam Endfire Planar Array With Integrated 2-D Butler Matrix for 60 GHz Chip-to-Chip Space-Surface Wave Communications

A two-dimensional Butler matrix feed network is designed, implemented, and integrated with a 60 GHz 2 × 2 circular patch planar array for chip-to-chip communications. The realized antenna module is a thin multilayer microstrip structure with a footprint small enough to fit over a typical multicore chip. The network enables endfire (azimuthal) scan of the array main beam in the four diagonal directions, which is demonstrated for the first time in this letter. The antenna module provides a seamless and practical way to achieve reconfigurable interchip communication in multicore multichip (MCMC) systems. A hybrid space-surface wave interconnect is proposed that takes advantage of surface-wave coupling. The matrix is a four-input, four-output, i.e., 4 × 4, network consisting of four interconnected quadrature (90°) hybrid couplers. A multiantenna module (MAM) consisting of five antenna modules that emulates diagonal interchip communication in MCMC systems is fabricated. The simulation and measurement of transmission coefficients between the antenna modules on the MAM are performed and compared.

Circularly polarized antenna array with a new sequential phase feed network utilizing directional coupler

This is a presentation of a new design of circularly polarized (CP) antenna array having a wide axial ratio (AR) bandwidth and high-gain. It uses an innovative feed network which consists of compact directional couplers and a delay line describing a new kind of sequential phase (SP) feed network. Furthermore, in this work, we report and discuss the features of the feed network and single element. In the following, the single element antenna and the 2 × 2 CP antenna array are designed, prototyped and tested. The antenna array is designed by a multilayer microstrip structure with a compact size of 75 × 52 mm2. Moreover, a metal reflector is utilized to enhance the antenna gain and achieve a unidirectional radiation pattern over the operating frequency band. According to the experimental results, the CP antenna array has a return loss (RL) bandwidth of 2.42 GHz (5.83–8.25 GHz), AR bandwidth of 1.11 GHz (6.76–7.87 GHz), and peak gain of 12.15 dBic. It seems that the performance of the proposed design is admirable for C-band frequency.

Resonance Frequency Calculation of a Multilayer and Multipatch Spherical Microstrip Structure Using a Hybrid Technique

This communication offers a rigorous analysis of the resonance frequency problem of a spherical microstrip structure mounted on a multilayer, dielectric-coated metallic sphere, with an electrically small radius. The structure consists of single or multiple metallic patches with arbitrary shapes. A full-wave analysis is employed with the use of proposed hybrid approach, combining the finite-difference technique with a spectral domain approach (SDA). In this approach, the finite-difference technique is applied in a cavity model to determine the current basis functions on the patch of an arbitrary shape. Then, the SDA is used to calculate the complex resonance frequencies of the structure. The numerical results concerning modes suitable for antenna applications are calculated. The presented results are verified by comparing them with the ones obtained from commercial software.

A design of octagon‐shaped 3‐dB ultra wideband coupler using multilayer technology

AbstractA design of a 3‐dB ultra wideband (UWB) coupler with compact size (35 mm × 15 mm), which operates between 3.1 and 10.6 GHz is presented in this article. The proposed design is accomplished by using multilayer microstrip structure, which is formed by three layers of conductor and two layers of substrate. The top and bottom layers consist of an octagon‐shaped microstrip lines and an octagon‐shaped slot in the middle layer. The design was fabricated on Rogers RO4003c substrate. Both of the simulation and measurement results are being compared with verify the coupler's performances in real environment. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:127–130, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27259

Reduced-size multilayer X-band filters with stacked resonators on a flexible organic substrate

This work presents the design of two four-pole, quasi-elliptic microwave bandpass filters with stacked open-loop resonators on an emerging low-loss organic dielectric material. Both filters are based on a multilayer microstrip structure that uses low-cost and flexible liquid crystal polymer substrates to produce a compact size. The first filter, which has a bandwidth of 17% at 9.3 GHz, was designed to control the high coupling strength between overlapped resonators without sacrificing its compact size. It has a measured 1.7 dB of insertion loss. The second filter uses the same topology, but its measured parameters include a bandwidth of 9% at 10.5 GHz and an insertion loss of 4.5 dB. To achieve the 9% bandwidth, two metallic patches were added between layers to limit the higher coupling between the overlapped resonators. Both bandpass filters have a footprint area reduction of at least 25% when compared to an equivalent single-layer, open-loop resonator filter.

Comparison between different models for the thin metallic substrate in multilayer microstrip structures

AbstractThe dispersive characteristics of multilayer microstrip structures with one thin metallic substrate are studied using the spectral‐domain approach. The numerical results of several approximate models are compared with that of the immittance approach as one exact model. The comparison shows that the widely used resistive sheet (R‐card) model is not appropriate to handle such structures over a broad frequency range. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1113–1117, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21556

EFFICIENT ANALYSIS OF FERROELECTRIC DEVICE FOR MICROWAVE PROPAGATION CHARACTERISTICS

ABSTRACT In this paper, we proposed a procedure to analyze a ferroelectric multilayer microstrip structure using the spectral domain method (SDM), which is used to find the microwave design parameters. In order to calculate the microwave characteristics of the proposed ferroelectric multilayer structure, propagation constant and effective permittivity are calculated from the SDM. The microwave design parameters of the proposed structure are optimized by using (1 + 1) evolution strategy (ES) combined with SDM. This novel numerical technique make it possible to take advantage of the high accuracy of the SDM as well as the high efficiency of the (1 + 1) ES.

Design of packaged microstrip antennas using wirebonding technique

A wirebonding technique is exploited to design novel miniature packaged antennas. Wirebond is readily used in manufacturing facilities for mass production of electronic components. Hence we have extended it to fabricate small antennas with a package for low cost mass consumption. Two new designs of small packaged antennas have been developed for the ISM band centred at about 2.45 GHz. The first design is a multilayer microstrip structure and the second design is a single-layer C-shaped structure with a novel proximal feed configuration to improve the impedance matching for thin microstrip antennas. The antennas feature 3.0–4.4% bandwidths, measuring 9.8% × 9.8% to about 10.9% × 10.9% of wavelength in length and width. Parametric studies are performed to investigate the performance of these antennas. The effects of finite ground, bondwires and isolated pads as well as package lids on the antenna performance have been evaluated.

Efficient electromagnetic modeling of three-dimensional multilayer microstrip antennas and circuits

An efficient method-of-moments (MoM) solution is presented for analysis of multilayer microstrip antennas and circuits. The required multilayer Green's functions are evaluated by the discrete complex image method (DCIM), with the guided-mode contribution extracted recursively using a multilevel contour integral in the complex /sub /spl rho//-plane. An interpolation scheme is employed to further reduce the computer time for calculating the Green's functions in the three-dimensional (3-D) space. Higher order interpolatory basis functions defined on curvilinear triangular patches are used to provide necessary flexibility and accuracy for the discretization of arbitrary shapes and to offer a better convergence than lower order basis functions. The combination of the improved DCIM and the higher order basis functions results in an efficient and accurate MoM analysis for 3-D multilayer microstrip structures.

Analysis and optimization of a phase shifter controlled by a piezoelectric transducer

This paper introduces a method for analyzing and optimizing a phase shifter controlled by a piezoelectric transducer (PET). To analyze the multilayer microstrip structure of the PET-controlled phase shifter, new equivalent single-layer (ESL) equations for the phase shift and loss calculations are developed and confirmed with spectral-domain analysis (SDA) of the moment method. A parametric analysis is accomplished with ESL equations and SDA, and optimization guidelines are suggested. An optimized PET phase shifter is demonstrated to operate up to 40 GHz with a maximum total loss of 4 dB and phase shift of 480/spl deg/. Measured results agree very well with calculations showing substantially smaller control voltage, size, and dispersion, as compared to previously published data. This new analysis and optimization technique for the PET-controlled phase shifter should be useful in the design of phased-array antennas and tunable microwave circuits.

Higher order full-wave analysis of multilayer microstrip structures

Higher order full-wave analysis of multilayer microstrip structures

Low loss multilayer microstrip line for monolithic microwave integrated circuits applications

This paper describes the multilayer microstrip structure using low dielectric constant polyimide as a buffer layer between the microstrip conductor and the GaAs substrate to reduce dissipation loss, especially for very high impedance microstrip lines. The new structure provides about half the dissipation loss and about 40% higher characteristic impedance in comparison to the conventional microstrip line on GaAs substrate having the same conductor widths. An empirical formula for the equivalent dielectric constant compatible with commercial computer-aided design tools was developed to design monolithic microwave integrated circuits (MMICs) using this medium. The multilayer microstrip structure is compatible with ITT's 4′ MSAG® process which uses polyimide for crossovers and scratch protection. The present structure has great potential in realizing low loss and wideband matching networks including low noise, high power, and high efficiency amplifiers, and passive components on GaAs substrate with improved insertion loss and bandwidth performance, and three-dimensional MMICs. © 1998 John Wiley & Sons, Inc. Int J RF and Microwave CAE 8: 441–454, 1998

Multilayer microstrip structure analysis with matched load simulation

This paper presents a generalized approach to the full-wave analysis of multilayer microstrip structures. One of the structures studied is a new kind of microstrip bandpass filter realized in a double-layer dielectric substrate configuration. This filter demonstrates the use of the third (vertical) dimension in the design of microstrip devices. The approach involves the mixed potential integral equation technique, the Method of Moments, and an S-parameter extraction technique based on a simple form of Matched Load Simulation. Simulated and measured results for various microstrip structures are presented and show good agreement. The approach is demonstrated in detail for 2-port structures, with an outline of how it can readily be extended to the n-port case.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Frequency-dependent permittivity values of multilayer microstrip structures using quasistatic modelling

A new method for determining the equivalent single-layer relative permittivity of a multilayer microstrip structure, based on a quasistatic analysis, is reported. The method is based on superimposing the charge density distribution of the multilayer structure on the single-layer equivalent structure. This then enables the frequency-dependent effective permittivity of the multilayer structure to be evaluated using the Getsinger dispersion model.