Foreword, Apr. 1975

The idea for this Special Issue on Microwave Communications grew out of a desire to couple the device and circuit designers within the microwave community more closely to the systems that utilize the outputs of their technologies. Accordingly, this Special Issue has been assembled in order to describe systems either currently operating, or under development, whose concept was stimulated, and existence made possible, by devices and circuits developed by members of the MTT Society and the organizations they represent.     

SiC materials-progress, status, and potential roadblocks

SiC materials are currently metamorphosing from research and development into a market driven manufacturing product. SiC substrates are currently used as the base for a large fraction of the world production of green, blue, and ultraviolet light-emitting diodes (LEDs). Emerging markets for SiC homoepitaxy include high-power switching devices and microwave devices for S and X band. Applications for heteroepitaxial GaN-based structures on SiC substrates include LEDs and microwave devices. In this paper we review the properties of SiC, assess the current status of substrate and epitaxial growth, and outline our expectations for SiC in the future.     

Microwave Photonics

The low-loss wide bandwidth capability of opto-electronic systems makes them attractive for the transmission and processing of microwave signals, while the development of high-capacity optical communication systems has required the use of microwave techniques in optical transmitters and receivers. These two strands have led to the development of the research area of microwave photonics. This paper reviews the development status of microwave photonic devices, describes their systems applications, and suggests some likely areas for future development     

A behavioral model development methodology for microwave components and integration in VHDL-AMS

The new generation of system-on-chip (SoC) incorporates digital, analogue, radiofrequency (RF)/microwave and mixed-signal components. Therefore, novel design methodologies must be developed to direct the design of these mixed-technology systems, which will have to include accurate behavioral libraries of devices and processes. Thus, this paper describes a behavioral modeling approach which generates accurate empirical models for RF/microwave devices and that can be easily integrated into a VHDL-AMS simulator. This approach is applied to a microwave tunable phase shifter and it is illustrated by the development of a VHDL-AMS model library for RF/microwave applications.     

微波测量的发展动态和趋势

微波测量是微波领域的重要方面,它直接关系到设计的微波系统和微波器件性能的好坏.本文从测量仪器的发展动态和趋势出发,论述了微波测量发展的六个可能方面,供读者参考.     

Impact of wide bandgap microwave devices on DoD systems

Radiofrequency (RF) semiconductor electronics enable military systems that operate in the microwave and millimeter wave frequency bands of 1-100 GHz. The performance of numerous electromagnetic systems could be enhanced by the inclusion of wide bandgap (WBG) microwave and millimeter wave devices, either as power amplifier or receiver elements. The demonstrated power performance has generally been six to ten times that of equivalent gallium arsenide or indium phosphide devices up through 20 GHz, with enhanced dynamic range and improved impedance matching. These characteristics provide an opportunity to significantly reduce the number of modules required for many active aperture antenna systems, hence, cost, while enabling new capabilities for shared apertures. Prior to realization of any WBG system deployment, however considerable development and maturation of WBG materials, devices, and circuits must yet ensue.     

大功率微波电子注器件及其发展

本文综述了大功率微波管最新进展,指出以电子注和场互作用为基础的大功率微波管,相对论高功率微波源,真空微电子器件是国防和信息系统的核心器件,其技术进展将为２１世纪军事电子装备的发展提供强有力的支持,也将对信息社会产生深远影响。     

高温超导/铁电薄膜可调谐微波器件应用研究简介

高温超导/铁电薄膜可调谐微波器件具有高可调率、低损耗的优势,在未来智能化通信系统中有良好的应用前景。本文简介了可调谐器件的研究意义和高温超导可调谐技术比较,综述了铁电薄膜可调谐器件的研究进展和代表性成果,总结了其中的关键技术问题并给出了建议。     

Microwave photonic multichip modules

The increasing use of microwave frequencies and gigabit per second transmission rates in optical-fibre systems and the corresponding interest in using optical techniques for microwave systems are spurring the development of microwave photonic circuits. Despite a considerable investment in research and development, monolithic photonic and optoelectronic integrated circuits have not entered into widespread production. The paper illustrates that for the majority of microwave photonic applications, the multichip module approach is better suited in terms not only of performance but also of economy and of ease of manufacture. The advantages of the silicon optical bench for optoelectronic integration are discussed in depth. It is then shown how, with suitable modifications, silicon-based multichip modules can also provide interconnections to microwave devices, thus creating microwave photonic multichip modules     

Foreword (Dec. 1983 [T-MTT])

It is evident to those connected to microwave and millimeter-wave technology that monolithic integrated-circuits technology has become increasingly vital to the development of various systems operating at microwave and millimeter-wave frequencies. A great deal of active effort is currently directed towards integrated-circuits technology and rapid progress is being made.     

Solid-state microwave relay systems in Japan

In response to the rapidly increasing demand for communication facilities, microwave relay systems have played an important role in Japan's telecommunications network because of their economy and capability for broadband transmission. Their progress has been marked during the past 20 years and this development has been supported by advances in such diverse fields as radio propagation, antennas, microwave and electronic circuitry, electron devices, and, particularly, in solid-state techniques. This article reviews the history of microwave relay systems and describes the past and expected future contributions of the solid-state technology to these systems.     

Quantum limited detection in tunnel junction mixers

A complete quantum generalization of microwave mixer theory is constructed for nonlinear single-particle tunnel junctions. The result represents a unification of the concepts used to describe these "classical" resistive mixers with the language of photon detection. Tunneling devices are predicted to undergo a transition from energy detectors to photon counters when operated at frequencies where the photon energy becomes comparable to the voltage scale of the dc nonlinearity. The small-signal video current response is found to approach one electron for each photon absorbed at high frequencies. In a heterodyne receiver, sufficiently nonlinear tunnel junctions are predicted to be capable of achieving the fundamental quantum noise limit for sensitivity in the detection of electromagnetic radiation. The theory presented here thus provides a framework for systematically extending the techniques of quantum electronics to considerably lower frequencies than are currently being exploited. Recent measurements of heterodyne mixer performance using superconductive tunneling devices are already beginning to approach quantum limited results at microwave and millimeter wave frequencies. Eventual application of tunnel barriers as photon detectors in the submillimeter and infrared spectral regions also appears to be possible, and the fast response times of such devices could give them an advantage over photoconductors even at the higher frequencies. The development of suitable nonlinear tunnel junctions contains the potential to bridge the present gap in quantum detectors between the infrared photon devices and microwave masers.     

Microwave and Millimeter-Wave Communications in Japan

This paper reviews the status of research and development in both microwave radio-relay systems and millimeter-wave transmission systems as well as the technical features in these fields, mainly developed under the auspices of Nippon Telegraph and Telephone Public Corporation (NTT). Recent activities have been the development of new solid-state devices and high-capacity systems. The application of solid-state techniques is being extended to systems of both analog and digital transmission, such as the 2700 multichannel telephone transmission system in frequency division multiplexing (FDM)-FM radio-relay system, an experimental 20-GHz PCM radio-relay system capable of 400 Mbits/s pulse transmission, and a guided millimeter-wave system of 800-Mbit/s transmission at 40-80 GHz. The microwave integrated circuit (MIC) is also becoming very important in utilizing these high-frequency regions, which should be a valuable resource in the future when a vast information transmission capability will be required.     

Microwave solid-state active devices

Solid-state devices have had a major impact on the development of microwave and millimeter-wave systems. Starting with development work dating back to the 1940s, a variety of two- and three-terminal device structures have been proposed, fabricated, and found their way into commercial and military applications. These devices have resulted in the realization of numerous systems that would not otherwise be possible. The device development effort has been closely linked to advances in semiconductor materials growth and processing technology. Many of the advanced device concepts can only be implemented with the advent of advanced materials growth technology, such as molecular-beam epitaxy, and fine-line lithography techniques, such as electron-beam lithography. Advanced materials technology has also provided the ability to fabricate heterostructures that permit the advantages of multiple material layers to be optimized for device applications. High-performance diodes and transistors are now available for use from UHF into the millimeter-wave spectrum, approaching terahertz frequencies. The development, operating principles, and state-of-the-art of various diode and transistor structures are reviewed     

Ferrite films for microwave and millimeter-wave devices

For microwave and millimeter-wave applications, there is increasing interest in using films rather than bulk ferrites. In some cases, such as magnetostatic wave devices, films provide definite performance advantages. In other cases, films may provide lower cost, smaller size, and enhanced compatibility with planar circuit designs such as monolithic microwave integrated circuits (MMIC). The author reviews some of the progress that has been made in development of single-crystal and polycrystalline ferrite films. He describes some of the ideas that are currently being considered for making these ferrites compatible with MMICs. The materials considered include garnets, spinels, and hexagonal ferrites     

The application of microwave techniques in lightwave systems

Microwave techniques have a significant role in advancing the state-of-the-art of lightwave systems. Applications include the analysis and design of structures to support lightwave propagation, the development of devices and circuits to modulate, demodulate, and process microwaves bandwidth signals on lightwave carriers, and the development of circuits to process microwave bandwidth baseband signals. The merging of microwave and lightwave technologies will open new opportunities in system design.     

High-reliability microwave silicon power transistor with stepped electrode structure and TiN diffusion barrier

A high-reliability microwave silicon power transistor is described that has a stepped electrode structure and TiN diffusion barrier. This structure, used for high-power and high-frequency devices, is discussed by comparing it to the conventional planar structure. The new structure permits microwave devices to achieve high levels of performance. For high-power dissipation devices having a beam lead metal system, however, the Au-Si reaction and localized Pt-silicide growth are major failure mechanisms. To improve these failures, the Ti layer must be thickened and further TiN applications in beam lead metal systems are discussed. Experimental results of high-temperature long-term operations proved that high-power microwave transistors with excellent reliability can be obtained by using a stepped electrode structure with TiN diffusion barrier.     

Advances in millimeter-wave subsystems in Japan

The authors describe the development trends and results of millimeter-wave systems in Japan in such fields as communication, radar, and measurement systems. The applications included are the W-40G waveguide transmission communication system, an automobile traffic control system using the 60-GHz band, a collision avoidance radar system for an automobile, a plasma electron density measuring system, and satellite communication. The authors describe the development of devices such as high-power FET amplifiers, traveling wave tube amplifiers (TWTAs), IMPATT amplifiers, low-noise amplifiers, and monolithic microwave integrated circuit (MMIC) devices used in constructing the millimeter-wave systems     

Dielectric materials, devices, and circuits

Dielectric materials are continuing to play a very important role in the microwave communication systems. These materials are key in realization of low-loss temperature-stable resonators and filters for satellite and broadcasting equipment, and in many other microwave devices. High dielectric-constant materials are critical to the miniaturization of wireless systems, both for the terminals and base-stations, as well as for handsets. In this paper, a sequential evolution of the dielectric materials applications in microwave devices will be reviewed. This includes dielectric waveguides, low-loss temperature-stable ceramic materials, dielectric resonators, and filters. The recent advances in the multilayer circuit modules, dielectric antennas, and ferroelectrics are also described     

雷达用微波功率器件的发展趋势

本文从雷达技术发展的角度阐述了雷达用微波功率器件的发展趋势，并指出今后将主要发展ＭＰＭ，ＭＭＩＣ，毫米波真空器件和真空微电子器件。