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     

Modified broadside-coupled microstrip lines suitable for MIC andMMIC applications and a new class of broadside-coupled band-pass filters

Modified broadside-coupled microstrip lines, suitable for microwave and millimeter-wave integrated and monolithic integrated circuit (MIC and MMIC) applications requiring wide bandwidths and tight couplings, are presented. Their analysis, based on the quasi-static spectral domain technique, is described. Using these broadside structures, a new class of broadside-coupled band-pass filters has been developed at X-band (8-12 GHz) with about 1-dB insertion loss. Fair agreement between the measured and calculated results has been observed even though a major approximation is used     

Double-sided MICs and their applications

The basic concept and features are presented of double-sided microwave integrated circuits (double-sided MICs), which effectively utilize various kinds of transmission lines on both sides of a substrate. The fundamental circuits such as 180° hybrids (magic Ts) and many application circuits described here are very useful in developing microwave and millimeter-wave band equipment. The concept of the double-sided MIC technique is also suitable for application to monolithic MICs     

New multilayer planar transmission lines for microwave andmillimeter-wave integrated circuits

New types of planar transmission lines employing multilayer structures are proposed for possible applications in microwave and millimeter-wave integrated circuits. Detailed investigations are presented through numerical results calculated using the spectral domain technique. The newly proposed transmission lines have many attractive features such as a large impedance range, flexibility and ability to realize complicated, densely packed integrated circuits, as well as miniaturization through the use of thin dielectric layers. Additionally, they possess all of the inherent advantages of the CPW and microstrip line. Their use in microwave circuits is exemplified through a low-pass filter realized using the new slot-coplanar lines with less than 0.5-dB insertion loss and better than 20-dB return loss. The filter's measured and calculated performances also agree well     

平面带隙结构在微波和毫米波集成电路中的应用

介绍了平面带隙结构在微波集成电路应用方面的最新进展。光子带隙(PBG)结构是具有带阻特性的周期结构,最初应用于光学领域,后来扩展到其他领域。目前从可见光到红外都有研究,在微波和毫米波频段也有应用。PBG结构可以采用金属、介质、铁磁或铁电物质植入衬底材料,或者直接由各种材料周期性排列而成。目前国内外所提出的光子带隙结构多种多样,一维和二维的平面带隙结构由于易于实现且便于集成,因而在微波毫米波集成电路中得到了广泛的应用。     

Tunable microwave and millimeter-wave band-pass filters

The authors present an overview of tunable microwave and millimeter-wave bandpass filters realized in different technologies. Some general design principles are described. Recent progress in the performance of various tunable filters is reported. The authors survey magnetically tunable filters (ferrimagnetic resonance filters, magnetostatic-wave filters, evanescent waveguide filters, E-plane printed circuit filters), electronically tunable filters, and mechanically tunable filters. The typical performance parameters are summarized. This comparison shown that none of these devices can simultaneously satisfy all requirements for perfect tunable filters. For microwave systems where multioctave tuning is essential, a YIG filter is an obvious choice. In systems where the requirement of high power handling capability combined with low insertion loss, predominates, mechanically tunable filters and magnetically tunable E-plane filters are recommended. If the tuning speed is a crucial requirement, varactor-tuned filters or E-plane filters with ferrite toroids are devices of choice. For millimeter-wave design, the most promising structures are ferrimagnetic resonance filters utilizing hexagonal ferrite resonators or, up to 60 GHz, magnetically tunable E-plane printed circuit filters     

Quasi-TEM analysis of multilayered, multiconductor coplanarstructures with dielectric and magnetic anisotropy including substratelosses

A quasi-TEM (transverse electromagnetic) analysis of multiconductor planar lines embedded in a layered structure involving lossy iso/anisotropic electric and/or magnetic materials is achieved. Conditions under which a quasi-TEM assumption is valid are theoretically determined. An efficient spectral-domain analysis is used to determine the complex capacitance and inductance matrices characterizing the transmission system. computation of the inductance matrix is reduced to the computation of an equivalent capacitance matrix when media characterized for a fully general permeability tensor are present. It is also shown that most actual monolithic microwave integrated circuit (MMIC) microstrip-type structures (where semiconductor substrates are present) and possible future applications including lossy magnetic materials can be analyzed by using the simple quasi-TEM model. The validity of the results has been verified by comparison with full-wave theoretical and experimental data on microstrip lines on magnetic substrates and slow-wave structures     

Micromachined devices for wireless communications

An overview of recent progress in the research and development of micromachined devices for use in wireless communication subsystems is presented. Among the specific devices described are tunable micromachined capacitors, integrated high-Q inductors, micromachined low-loss microwave and millimeter-wave filters, low-loss micromechanical switches, microscale vibrating mechanical resonators with Q's in the tens of thousands, and miniature antennas for millimeter-wave applications. Specific applications are reviewed for each of these components with emphasis on methods for miniaturization and performance enhancement of existing and further wireless transceivers     

A Generalized Spectral Domain Analysis for Coupled Suspended Microstriplines with Tuning Septums

An efficient computation method is developed for solving the microstrip-type structures in which a number of conducting strips are located on several interfaces of dielectric layers. The method is applied to the coupled suspended microstripline with tuning septums on the underside of the suspending dielectric layer. The numerical solutions obtained by the new method are compared with available data. The method is believed useful in the design of tightly coupled structures such as the 3-dB hybrid as well as of transitions between different transmission lines for microwave and millimeter-wave integrated circuit application.     

微机械传输线的毫米波应用

以几种典型的毫米波波段微机械传输线结构为研究对象，讨论了近几年的最新研究成果，包括微带、带状线、开放和封闭的共面波导。微机械传输线能够充分降低介质损耗，具有传输损耗小、工作频带宽、色散小、制作工艺能与传统集成电路工艺兼容等特点，是毫米波波段平面集成传输线应用的首选技术方案，同时微机械传输线的出现为毫米波单片集成电路以及毫米波系统的微型化提供了解决方案。     

Hybrid integration technology of planar circuits and NRD-guide forcost-effective microwave and millimeter-wave applications

An architecture called the hybrid planar/non-radiative-dielectric (NRD) waveguide integrated technology is proposed as a building block for constructing microwave and millimeter-wave circuits. This hybrid approach of integration offers a unique possibility of exploiting inherent complementary advantages of planar structures and NRD waveguides for low-cost wireless applications while eliminating the potential drawbacks associated with both dissimilar structures. Compared to the existing NRD-guide related technology, the proposed framework consists of relocated planar structures on the top and/or the bottom plates of an NRD-guide, sharing the common ground planes. Such a hybrid scheme is particularly suitable for millimeter-wave systems in which active devices can be made with the planar-line technique while passive components can be made with the NRD-guide technique. The two subsets of a complete functional system are interconnected through a class of aperture-based transitions which can be designed to have wide-band performance. In addition, the multichip module (MCM) technique is readily achieved under this proposed scheme. Experimental prototypes, including passive-component and active-device, based on the new hybrid technology presented in this paper, show that the novel hybrid technology promises to be useful in the design of future microwave and millimeter-wave circuits and systems     

MIMIC from the Department of Defense perspective

The microwave and millimeter wave monolithic integrated circuits (MIMIC) program is a Defense Advanced Research Projects Agency initiative to provide affordable, reliable, and reproducible microwave and millimeter-wave circuits in monolithic format for use in US Department of Defense (DoD) systems. The objectives of the program, progress being made toward meeting those objectives, and some planned future work are described. The overall program object is to provide the needed microwave and millimeter-wave products at a price that will allow their use in fielded DoD systems, that meet all required electrical, mechanical, and environmental parameters, and that continue to operate reliably for the time necessary to fulfil their intended application. Programs in progress include work on gallium arsenide epitaxial growth techniques; multiple chip ceramic packages, process, device, and circuit modeling; on-wafer testing techniques; and advanced fabrication techniques     

Magnetostatic wave technology: a review

Magnetostatic wave (MSW) technology has been under investigation for more than a decade. Using ferrimagnetic films such as liquid-phase epitaxial (LPE) yttrium iron garnet (YIG) films, MSW devices and subsystems offer instantaneous bandwidths of up to 1 GHz at operating frequencies in the microwave bands (0.5-26.5 GHz). Because MSWs travel with velocities two-to-four orders of magnitude slower than electromagnetic waves, compact devices can be built using hybrid and monolithic microwave integrated circuit (MMIC) techniques. These devices include delay lines, dispersive delay lines, filters, resonators, and directional couplers. Subsystems using these devices, such as electronically tunable delay lines channelized filter banks, delay-line discriminators, oscillators, and frequency multipliers can be used for applications in signal identification, control and processing directly at microwave frequencies. An overview of the MSW technology is presented and an assessment of the various devices and subsystems that can be built using thin and thick LPE-YIG films is provided     

A fast hybrid field-circuit simulator for transient analysis of microwave circuits

A plane-wave-time-domain accelerated time-domain integral-equation solver is coupled to a SPICE-like transient circuit simulator to analyze electromagnetic platform-circuit interactions. The hybrid field-circuit simulator simultaneously solves surface-wire-volume time-domain integral equations that model electromagnetic interactions with the platform and modified nodal analysis equations that govern the behavior of the potentially nonlinear lumped circuits. A shielded nonlinear microwave amplifier is analyzed using the proposed scheme, and its immunity to electromagnetic interference is assessed.     

间隙波导技术及其空间应用

间隙波导(GW)是一种基于非接触电磁带隙(EBG)结构的新型人工电磁(EM)材料，其独特的非接触结构和宽带电磁屏蔽特性在构建新型电磁传输线及屏蔽结构方面显示出极大的优势和灵活性，为微波毫米波部件、电路及天线等领域带来了新的研究视角和实现途径，近年来引起了广泛关注。该文首先简要介绍了间隙波导概念和原理，分析了其技术优势；进一步，根据不同的研究及应用领域分类，全方位地归纳总结了间隙波导技术相关的国内外研究进展情况；最后，结合空间技术背景和发展需求，探讨了间隙波导在空间微波毫米波技术中的应用前景，提出了基于间隙波导技术的非接触式无源互调干扰控制方法及堆叠集成毫米波电路系统两个重要的应用方向。该文工作可为间隙波导技术相关研究和应用提供一定的借鉴与参考。     

Millimeter-wave wide-band amplifiers using multilayer MMICtechnology

This paper describes millimeter-wave wide-band single-ended and balanced amplifiers using novel multilayer monolithic microwave/millimeter-wave integrated circuit (MMIC) technology. The fundamental characteristics of thin-film transmission lines and a 50-GHz-band multilayer MMIC directional coupler are described through measurements up to 60 GHz. A single-ended amplifier fabricated in a 1.1 mm×0.8 mm area, shows a gain of about 12 dB with a noise figure of better than 5 dB around 50 GHz. A balanced amplifier fabricated using the multilayer MMIC directional couplers and single-ended amplifiers, shows a gain of 10-17 dB with input and output return losses of better than 14 dB from 33 to 53 GHz. The transmission lines and directional couplers can be effectively combined with millimeter-wave active circuits without degrading the circuit performance or increasing the circuit area. To our knowledge, these are the first millimeter-wave active circuits employing multilayer MMIC technology     

Millimeter-wave atmospheric turbulence measurements: Instrumentation, selected results, and system effects

Increasing interest in and greater usage of the millimeter-wave frequency bands has resulted in a need for better characterization of atmospheric effects at these frequencies. While attenuation is recognized as the most significant effect, recent measurements of fluctuations in intensity and phase caused by atmospheric turbulence have shown that these phenomena will also degrade system performance at both millimeter-wave and microwave frequencies. This paper describes the millimeter-wave and meteorological instrumentation used to make these measurements and gives selected results. It is determined that phase fluctuations as great as 1.5 radians and intensity fluctuations as large as 2.8 dB are observed over a 1370 m path in hot, humid weather. The effects of these fluctuations on the performance of practical, existing microwave phased array and monopulse systems are assessed. It is determined that phase fluctuations in particular will degrade the performance of microwave adaptive nulling arrays and monopulse trackers.     

Microscopic theory of hydrogen in silicon devices

Incorporation of hydrogen has a strong effect on the characteristics of silicon devices. A fundamental understanding of the microscopic mechanisms is required in order to monitor and control the behavior of hydrogen. First-principles calculations have been instrumental in providing such understanding. We first outline the basic principles that govern the interaction between hydrogen and silicon, followed by an overview of recent first-principles results for hydrogen interactions with silicon. We show that H₂ molecules are far less inert than previously assumed. We then discuss results for motion of hydrogen through the material, as relating to diffusion and defect formation. We also discuss the enhanced stability of Si-D compared to Si-H bonds, which may provide a means of suppressing defect generation. We present a microscopic mechanism for hydrogen-hydrogen exchange, and examine the metastable ≡SiH₂ complex formed during the exchange process. Throughout, we highlight issues relevant for hydrogen in amorphous silicon (used in solar cells, sensors and displays) and in Si-SiO₂ structures (used in integrated circuits). The broader impact of first-principles calculations on computational electronics will also be discussed     

An efficient two-dimensional graded mesh finite-differencetime-domain algorithm for shielded or open waveguide structures

A finite-difference-time-domain (FDTD) algorithm for the efficient full-wave analysis of a comprehensive class of millimeter-wave and optical waveguide structures is described. The algorithm is based on a two-dimensional graded mesh combined with adequately formulated absorbing boundary conditions. This allows the inclusion of nearly arbitrarily shaped, fully or partially lateral open or shielded guiding structures with or without layers of finite metallization thickness. Moreover, lossy dielectrics and/or lossy conductors are included in the theory. The algorithm leads to a significant reduction in CPU time and storage requirements as compared with the conventional three-dimensional eigenvalue FDTD mesh formulation. Dispersion characteristic examples are calculated for structures suitable for usual integrated circuits, such as insulated image guides, ridge guides, dielectric waveguides, trapped image guides, coplanar-lines and microstrip lines. The theory is verified by comparison with results obtained by other methods