Dielectric Waveguide Microwave Integrated Circuits---An Overview

An integrated circuit technique for microwave and millimeter wavelengths which uses refractive-type waveguides and signal processing coupled with planar integration techniques characteristic of microstrip microwave integrated circuits (MIC's) is described. Following a comparison of the optical and millimeter approaches to this circuit technique, a discussion of transmission lines and components for millimeter wavelengths is presented. System applications are also described.     

Frequency and time domain characterization of microstrip-ridgestructures

Microstrip-ridge structures, i.e., conducting strips which are mounted on ridges and are in the close proximity of other conductors on other ridges, are found in submillimeter/terahertz monolithic circuits in conjunction with layered, ridged dielectric waveguides; in millimeter-wave monolithic circuits as microslab lines; in microwave monolithic circuits as integrated traveling-wave optical modulators; and in VLSI circuits as interconnects. A hybrid full-wave frequency domain technique which uniquely synthesizes well-known integral equation and mode-matching methods is shown to be applicable to the study of microstrip-ridge structures. Unlike most other integral equation techniques, the integral equation-mode matching (IEMM) technique is capable of characterizing a wide variety of nonplanar structures. Time domain results are obtained by utilizing a Fourier transform and an equivalent circuit model to evaluate the response at each frequency point. To introduce this method, several two-dimensional structures-specifically, coupled microstrips on ridges, coupled microstrip with an etched groove, and an electrooptic modulator-are examined     

New MIC Power Dividers Using Coupled Microstrip-Slot Lines: Two-Sided MIC Power Dividers

New microwave integrated circuit (MIC) power dividers have been proposed. These power dividers utilize both substrate surfaces and employ coupled microstrip-slot lines, microstrip lines, and slotlines; therefore, we make use of the two-sided MIC technique. The out-of-phase-type power dividers, as well as the in-phase-type circuits, can be constructed by the circuit configuration method described in this paper. Coupled microstrip slot lines, an important component of the power dividers, have been analyzed by the spectral-domain method, and their characteristics have been calculated and the numerical results shown for several different structural parameters for the purpose of designing power dividers. The out-of-phase-type power divider was fabricated at the 26-GHz band and good performance achieved, confirming the calculated accuracy through experimental results. The new two-sided MIC power dividers are expected to have wide applications at the millimeter-wave band.     

Losses of Microstrip Lines

This article summarizes state-of-the-art information on losses of single and coupled microstrip lines. Conductor loss, substrate loss (for pure dielectric or magnetic materials), and radiation loss are considered along with the effect of dispersion. Finally, a rough comparison is made between the losses of microstrip and that of several other types of lines used in microwave integrated circuits.     

Experimental Study on Isolation Characteristics Between Adjacent Microstrip Lines Employing Periodically Perforated Ground Metal for Application to Highly Integrated GaAs MMICs

Using a periodically perforated ground metal (PPGM) on GaAs monolithic microwave integrated circuit (MMIC), a microstrip line structure with a high isolation characteristic between lines was developed. The high isolation characteristic was originated from a resonance between adjacent microstrip lines employing PPGM. According to experimental results, a much better isolation characteristic was observed from the adjacent microstrip lines employing PPGM compared with conventional microstrip lines, and the frequency range for high isolation was easily controlled by changing the PPGM structure. Above results indicate that microstrip lines employing PPGM are very useful for application to compact signal/bias lines of highly integrated MMIC requiring a high isolation characteristics between lines.     

Planim: a new concept in the design of MIC filters

The planar circuit approach for the characterisation of microstrip circuits is combined with the image parameter method to give a new powerful technique for integrated circuit filter design (planim). The inclusion of two-dimensional effects in the synthesis procedure makes the planim approach particularly suited for monolithic microwave circuits. The design of microstrip filters with extremely wide stopbands is shown as an example.     

全等宽平行耦合微带线带通滤波器的设计

半波长平行耦合微带线带通滤波器由于其结构紧凑,第二通带的中心频率3倍于主通带中心频率,因而在微波集成电路中获得广泛应用。本文提出一种新的设计方法：耦合线节级联直接设计法。这一方法比传统设计方法简便,适用相对带宽范围较宽,为30～80%,而且可以采用全等宽耦合线,因而滤波器结构简洁。     

Intermixing optical and microwave signals in GaAs microstripcircuits for phase-locking applications

The microwave modulation of the interference generated by optical beams that are reflected from the top and bottom surfaces of GaAs substrate adjacent to a microstrip line is studied. The detected modulation is used to directly characterize the electrooptic effect. This optical-microwave intermixing technique is applied to phase-lock a free-running microwave oscillator with picosecond laser pulses. One potential application of this technique is for the optical on-wafer characterization of MMICs (monolithic microwave integrated circuits)     

具有抑制谐波性能的微带带通滤波新电路

针对分布参数滤波网络存在寄生通带问题,本文提出一种新的微带带通滤波电路.对其滤波特性进行了理论分析,给出了电路的结构形式和有关计算公式.它由特定组合传输线与平行耦合微带线单元级联构成,结构简单.计算及实验结果表明这种新的滤波电路具有良好的谐波抑制特性.这种滤波电路用在微波振荡器或放大器输出端,可以有效地抑制谐波输出.     

Applications of integrated circuit technology to microwave frequencies

Integration techniques suitable for microwave circuits have been developed. Various aspects of the technology of integration of microwave circuits are reviewed and the reasons for choosing the hybrid approach instead of the monolithic approach and thin-film metallization instead of thick-film are discussed. Design data relating circuit performance to substrate roughness and thickness of thin-film metal adhesion layers are presented. Propagation and radiation characteristics of microstrip lines are discussed. Design equations for thin-film lumped-element passive components are given. Exampies of various microwave integrated circuits are shown.     

An Analysis of Gap in Microstrip Transmission Lines

Although microstrip transmission lines have been widely used in microwave integrated circuits, the discontinuity structures in the microstrip transmission lines such as a gap, an abruptly ended strip conductor, and so on, have hardly been analyzed. An analytical method and numerical results for a gap capacitance in the microstrip transmission line are described. The equivalent circuit parameters are formulated with three-dimensional Green's functions, based on a variational principle. The numerical results are in good agreement with the published experimental data. The fringing effect of an abruptly ended strip conductor is also investigated.     

Film technology in microwave integrated circuits

A review of the material technology for microwave integrated circuits (MICs) is presented. The types of microwave circuit media that have been used are described and classified as a function of the amount of size reduction or integration which corresponds to the effective dielectric constant of the media. The materials used for substrates, conductors, dielectrics, and resistors are considered in terms of the requirements for microwave circuits. The fabrication of multilayered thin-film circuits and the various thin-film combinations that have been used in MICs are discussed. The various loss contributions for microstrip circuits produced by thin- and thick-film technology and substrate material are compared with each other as a function of frequency. It is concluded that microwave circuits operating at frequencies 2 GHz and above require thin-films on pure smooth substrates.     

一种新型一维微带PBG单元结构

通过对传统二维微带 PBG 结构的研究,针对微带线的传播常数是微带线相对于接地板上周期孔眼的两个主轴的位置和方向的敏感参数而不能根据实际情况任意布线的缺点,提出了一种新型一维微带 PBG(photonic bandgap)单元结构及其等效 L-C 电路模型。本文提出的 PBG 传输线可以应用于微波集成电路中,能够减小电路尺寸,且可以抑制高次谐波的产生。     

A Coupled-Line Model for Dispersion in Parallel-Coupled Microstrips (Short Papers)

A new circuit model is derived for parallel-coupled microstrip consisting of two separate pairs of coupled lines. Each pair consists of a homogenoeus TEM line coupled to a homogeneous TE line. One pair represents the hybrid even mode, the other represents the odd mode. Data calculated from the model are compared with experimental dispersion data for various parallel-coupled microstrip geometries. Agreement is excellent. The procedure for deriving the equivalent circuit is an example of a general technique for using coupled lines to model longitudinally uniform but transversely inhomogeneous lossless waveguide.     

A Broadband Substrate Integrated Waveguide (SIW) Planar Balun

A broadband planar balun is presented in this work that makes use of a substrate integrated waveguide (SIW) technique using a printed circuit board process. The proposed balun structure is able to operate at millimeter wave frequencies and it does not require any tight line coupling sections as frequently used in monolithic microwave integrated circuit balun design. In addition, this balun can be integrated with other planar topologies including nonplanar circuits made of the same substrate for achieving high efficiency. This balun structure consists of a 3 dB SIW power divider and microstrip lines that are placed on both sides of the substrate at balanced ports to obtain an 180deg phase shift. The concept is validated by simulations and measurements. Our measured results suggest that a 10 dB return loss at unbalanced port can easily be achieved across a 42% bandwidth from 19 to 29 GHz. Measured amplitude and phase imbalance between two balanced ports are within 1 dB and plusmn5deg, respectively.     

FDTD analysis of high frequency electronic interconnection effects

A full-wave analysis of coupled high-frequency interconnect discontinuities is presented using the finite-difference time-domain (FDTD) method. The electromagnetic effects of two via holes on microstrip lines in close proximity to one another are examined and equivalent circuits are presented. The effects of two adjacent lines with bond wires, used, for example, to connect a die to the leadframe of an integrated circuit (IC) package are also analyzed. Frequency domain results are presented by using the discrete Fourier transform of the time-domain results. Guidelines regarding the effective use of the FDTD code including the use a priori calculated electric field distribution in the excitation plane, and the use of a weighted ϵ_r,eff to minimize reflections at the absorbing boundaries are described. The obtained FDTD results and the developed equivalent circuit models show the importance of radiation effects at frequencies beyond 20-30 GHz, the possibilities of reducing the inductive effect of bond wires by using two parallel bond wires instead of one, and the importance of including mutual inductance elements in the equivalent circuit model to account for the crosstalk between parallel vias across a ground plane     

Modéles de lignes simples et couplées,idéales et à pertes,pour la CAO des circuits gigabits

This paper describes the principles underlying a library of single and coupled lines, ideal or lossy for the cad of interconnections in gigabit logic circuits. The models are based upon the quasi-TEM approximation, they exploit the method of characteristics and direct simulation in the time domain which give good calculation efficiency. The modeling of lossy coupled lines is original and utilizes modal decomposition in the time domain which may be performed in good approximation for coupled lines of equal widths. The models are integrated in the circuit simulator Macpro to perform the cad of circuit microstrip interconnections. Simulations including the response of the instrumentation are compared with the corresponding measurements on typical configurations of lossy coupled lines deposited on a semi-insulated GaAs substrate.     

Equivalent circuit modeling of losses and dispersion in single andcoupled lines for microwave and millimeter-wave integrated circuits

Losses and dispersion in open inhomogeneous guided-wave structures such as microstrips and other planar structures at microwave and millimeter-wave frequencies and in MMICs (monolithic microwave integrated circuits) have been modeled with circuits consisting of ideal lumped elements and lossless TEM (transverse electromagnetic) lines. It is shown that, given a propagation structure for which numerical techniques to compute the propagation characteristics are available, an equivalent circuit whose terminal frequency and time-domain properties are the same as the structure can be synthesized. This is accomplished by equating the network functions of the given single or coupled line multiport with that of the model and extracting all the parameters of the equivalent circuit model by using standard parameters identification procedures. This model is valid over a desired frequency range and can be used to help design both analog and digital circuits consisting of these structures and other active and passive elements utilizing standard CAD (computer-aided design) programs. To validate the accuracy and usefulness of the models, results for a mismatched 50-Ω line in alumina and a high-impedance MMIC line stub are included     

Single feed proximity coupled circularly polarized microstripmonofilar Archimedean spiral antenna array

The analysis is presented for a microstrip feed proximity coupled monofilar Archimedean spiral four-element antenna array. Interactions between the microstrip corporate feed and the radiating elements are rigorously included. Results demonstrate that circular polarization can be achieved with proper spiral arm length. Polarization of either sense is controlled by the location of the feedline. The 3-dB axial ratio (AR) and voltage standing wave ratio (VSWR) bandwidths are 9%. The antenna is small (2R/λ₀=0.33) and the interelement spacing is 0.51λ₀. The microstrip feed produces a completely planar antenna system, which is compatible with microwave integrated circuits (MIC) and monolithic microwave integrated circuits (MMIC)