Circular TE/sub 0n/ Mode Filters for Guided Millimeter-Wave Transmission

A millimeter-wave circular TE/sub 01/ mode waveguide generates undesired circularly symmetric modes (TE/sub 02/, TE/sub 03/ modes, etc.) in bends or at discontinuities along a waveguide line. This paper describes the theory and experiment on the TE/sub 02/ and TE/sub 03/ mode filters developed for guided millimeter-wave transmission. The experimental results of two improved TE/sub 03/ mode filters show that the attenuation of the TE/sub 03/ mode is more than 16 dB for one type over the 40-70-GHz range. The TE/sub 01/-mode insertion loss of another type is about 0.2 dB over the 40-80-GHz range. The present mode filters can be applied to various high-speed guided rnillimeter-wave systems currently under development.     

基于FPGA的毫米波数据传输系统的实现

为满足现在高速的信息传输需求,结合国内外研究现状,针对毫米波频段的传输衰减较大导致通信距离受限的问题,以毫米波通信系统为平台,设计了基于大规模阵列天线和毫米波频段的物理层传输帧结构,采用并行同步处理算法及基于格雷序列相关算法等,提高了高速通信的同步速度和同步性能,实现了毫米波远距离高速通信,经过实物实验验证,系统在5km距离上空口速率可达1Gbps。     

Millimeter-Wave Fin-Line Characteristics

This paper presents an analysis of the fin line. The spectral-domain technique is used to determine both wavelength and characteristic impedance. Numerical results are compared with known data for ridged waveguide slab-loaded waveguide, and slotline. Design curves are presented for practical millimeter-wave fin line structures.     

Two-Cavity Ring-Type Channel-Dropping Filters for a Millimeter-Wave Guided Wave Communication System (Correspondence)

Newly developed two-cavity ring-type filters for a millmeter-wave communication system are described. They are used in a five-channel transmit and receive multiplexer which operates in the 50-GHz frequency band. The pulse response and interchannel crosstalk characteristics for 250-Mbit PCM-AM or PCM-PSK transmission were calculated and compared with experimental results.     

Evaluation of an Experimental Packetized Speech and Data Transmission System

The design objectives and test results of a new services integrated system using a packetized speech technique are presented. First, several important design parameters are investigated through theoretical analysis and computer simulation. Second, an experimental system for confirming the choice of design parameters as well as measuring the speech and data communication quality is described, and the test results of this system are discussed.     

Transmission Performance Improvement in Microwave/Millimeter-Wave Optical System Using Chirped Fiber Grating

A chirped fiber grating (CFG) written by the moving fiber/phase mask scanning beam technique with a uniform mask is used to demonstrate the dispersion compensation in the externally modulated microwave/millimeter-wave over fiber system. It is found that the use of the CFG is an efficient way to compensate for the severe RF power degradation induced by the fiber chromatic dispersion, which results in a significant improvement in the transmission performance. The signal to noise ratio is improved from 4.8 dB to 24.4 dB when 10.58 GHz RF signal carrying 5 Mbit/s QPSK format data is transmitted over 35 km single mode fiber.     

Efficient Transmission Scheme for AWG-Based DWDM Millimeter-Wave Fiber-Radio Systems

We propose and demonstrate an upstream transmission scheme using a semiconductor optical amplifier (SOA) for arrayed waveguide grating (AWG)-based dense wavelength-division-multiplexed (DWDM) millimeter-wave fiber-radio systems and show improved link performance. In our scheme, unused optical carriers from the cyclic AWG in the downlink (DL) are tapped for uplink (UL) transmission. An SOA in conjunction with the AWG simultaneously amplifies the DL RF subcarriers and UL optical carrier, thus improving carrier-to-sideband ratio in the DL while also yielding an improved power budget for the UL. Our experimental results show that the proposed scheme can be a practical solution for future bidirectional wavelength interleaved DWDM transmission systems     

ROF系统中毫米波生成技术的研究

光载射频（ROF）通信系统已经成功应用于移动通信系统、智能交通控制、室内信号的覆盖等众多领域。毫米波生成技术作为ROF的关键技术,得到了很大的发展,基于外部调制技术、光外差技术和上变频技术的新方案不断地涌现。从ROF的原理着手,研究了整个系统中毫米波生成的几种常见方法,对其优缺点进行了分析,最后简单介绍了ROF的应用领域。     

Propagation Parameters of Coupled Microstrip-Like Transmission Lines for Millimeter-Wave Applications

A variational expression is derived for the propagation parameters of coupled microstrip-like transmission lines for millimeter-wave applications using the "transverse transmission line" method. Numerical results are presented for the coupled inverted microstrip lines, and for the coupled suspended microstrip lines. The effects of the top and sidewalls and also of the finite thickness of strip conductors on the even- and odd-mode impedances are studied. The use of a dielectric overlay in equalizing the even- and odd-mode phase velocities is investigated.     

A Versatile Millimeter-Wave Imaging System

A new millimeter-wave imaging system has been assembled at the Naval Research Laboratory and flight-tested using the NASA/ Wallops C-54 aircraft. The system incorporates an oscillating mirror and interchangeable radiometer units making it particularly adaptable to variations in its operational frequency, polarization, and angular resolution. Flight tests of the system have been conducted at 90 GHz and simultaneously at 22 and 31 GHz using a dual frequency radiometer. The imaging system and data processing are described and some of the initial flight test results at 90 GHz are presented.     

毫米波个人卫星通信系统

本文论述了毫米波段个人通信的系统概念，包括通信系统的结构、卫星系统以及地面终端系统。由于采用灵活的信道建立方法、有效的频率复用技术以及诸如基带信道切换处理器和调制解调器等星载通信设备，该系统信道容量大、性能优越。     

Optimization of Millimeter-Wave RoF System Structure

Based on the seamless integration of broadband optical and wireless access networks,millimeter-wave Radio over Fiber (RoF) technology is considered to be a promising solution for the next generation access networks which will provide high capacity and flexibility with low cost.But due to its large cost to realize,the system architecture needs to be optimized.In the millimeter-wave optical generation part,optical heterodyning method can be introduced to generate a high-frequency millimeter-wave signal using a low-frequency signal source.And the system efficiency can be greatly improved based on injection-locking of a semiconductor laser.In the downlink,the transmission distance can be greatly enhanced using single-sideband modulation.And the single-mode modulation (single-sideband modulation) based on an injection-locked semiconductor laser is a much simpler solution.In the uplink,direct modulation of optical heterodyning signal can be used to realize the down-conversion of uplink millimeter-wave signal,which simplifies the receiver structure at the centre office.In the wavelength division multiplexing millimeter-wave RoF duplex system,the wavelength reuse in both downlink and uplink can save the wavelength resource in the whole system,which improves its efficiency.     

毫米波室内传播特性的研究

毫米波的宽频带特性可以有效地解决高速（宽带）无线接入中面临的许多问题。本文从室内电波传播的基本概念出发,系统地介绍和分析了国内外近年来在毫米波室内传播方面的研究成果,包括建筑材料的毫米波特性、毫米波传播特性的实测和计算机仿真。     

Nonlinear and Intermodulation Characteristics of Millimeter-Wave IMPATT Amplifiers

An analysis and experimental results of intermodulation distortion characteristics of millimeter-wave IMPATT amplifiers are presented. Design considerations for linear IMPATT amplifiers and tradeoffs between the small-signal gain and intermodulation distortion are discussed.     

Nonlinear and Large-Signal Characteristics of Millimeter-Wave IMPATT Amplifiers

Experimental results obtained with millimeter-wave IMPATT amplifiers are presented. Nonlinear and large-signal characteristics of stable IMPATT amplifiers and injection-locked IMPATT oscillators are described. Amplifier circuit configuration, diode characteristics, and measured effects of bias current, temperature, and large-signal level on gain, bandwidth, power saturation, and phase-delay characteristics are discussed in detail.     

Millimeter-Wave over Fiber Systems Using Hybrid OCDM/WDM Transmission

In this paper, we propose and simulate 2 OCDM × 4 WDM transmission system for a millimeter-wave (60 GHz) over fiber system to be used in broadband wireless access networks (BWANs). The general system setup is devised and the necessary building blocks identified. Results gathered (for a 155 Mbit/s per user system) under worst case parameter specifications and settings suggest indicate that system performance is severely limited by optical multiuser interference (OMUI) penalties. Several methods to reduce the OMUI limitations are described. These methods should ensure that this transmission scheme possible wavelength-reuse option for future MMW BWANs.     

Gold-Plated Micromachined Millimeter-Wave Resonators Based on Rectangular Coaxial Transmission Lines

Resonators based on microfabricated rectangular coaxial (recta-coax) transmission lines are presented. The resonators were fabricated using a multilayered nickel electroplating process that enables the fabrication of three-dimensional structures. As a method to improve performance, gold was plated on the resonators using an electroless process. A model for predicting the effect of the plating on a resonator quality (Q) factor is presented and verified by measurements. Measured resonators show that the plating can increase the Q factor of nickel resonators by over 50% at frequencies above 44 GHz. Utilizing gold plating, 50-Omega resonators are demonstrated at 44 and 60 GHz with unloaded Q factors of 213.1 and 242.3, respectively     

Low-Power Testing of Losses in Millimeter-Wave Transmission Lines for High-Power Applications

We report the measurement of small losses in transmission line (TL) components intended for high-power millimeter-wave applications. Measurements were made using two different low-power techniques: a coherent technique using a vector network analyzer (VNA) and an incoherent technique using a radiometer. The measured loss in a 140 GHz 12.7 mm diameter TL system, consisting of 1.7 m of circular corrugated waveguide and three miter bends, is dominated by the miter bend loss. The measured loss was 0.3?±?0.1 dB per miter bend using a VNA; and 0.22?±?0.1 dB per miter bend using a radiometer. Good agreement between the two measurement techniques implies that both are useful for measuring small losses. To verify the methodology, the VNA technique was employed to measure the extremely small transmission loss in a 170 GHz ITER prototype TL system consisting of three lengths of 1 m, 63.5 mm diameter, circular corrugated waveguide and two miter bends. The measured loss of 0.05?±?0.02 dB per miter bend may be compared with the theoretical loss of 0.027 dB per miter bend. These results suggest that low-power testing of TL losses, utilizing a small, simple TL system and a VNA, is a reliable method for evaluating performance of low-loss millimeter-wave TL components intended for use in high-power applications.