Submillimeter wave communication versus millimeter wave communication

This paper studies the performance of a submillimeter wave antenna operating between frequencies 0.1 THz and 10 THz with a 4-cyano-4-pentylbiphenyl [5CB] substrate. Since the size and shape of the antenna impact its gain/directivity, resonant frequency, bandwidth, and efficiency, the two antenna types considered in this paper are: (a) Rectangular Patch Antenna (RPA), and (b) Cylindrical Dielectric Resonator Antenna (CDRA). Here a submillimeter wave antenna is compared with a millimeter wave (a few GHz to 100 GHz) antenna. These popular mm-wave antennas are chosen for the submillimeter wave antenna in order to understand changes in their performance as the result of changes in their geometrical shape. FEldberechnung bei Korpern mit beliebiger Oberflache (FEKO) software is used for the design and calculation of the Three-Dimensional (3D) ElectroMagnetic (EM) patterns. This paper also concentrates on the design and analysis of a massive submillimeter wave Multiple-Input Multiple-Output (MIMO) (8 by 8) RPA and CDRA.     

Nonlinear wave propagation in traveling–wave amplifiers

A method is given for computing the efficiency of traveling-wave amplifiers with high gain and low C, including the effects of space charge and attenuation. The ballistics of the electrons is governed by the Boltzmann transport equation which, together with the circuit equation, is solved in a power series expansion of the input voltage. Only the first two terms of this series are computed and various nonlinear results are given in the form of curves. It appears that for small C and small convergence parameters, overtaking affects the nonlinear operation slightly.     

波浪浮标测波方法比较

波浪浮标是一种无人值守,自动检测的常用的海洋监测设备。在介绍国内外波浪浮标研究使用现状的基础上,对比分析了基于加速度传感器和GPS传感器的两种波浪浮标的共同点和不同点。     

Shielded rectangular dielectric wave guides for millimeter wave integrated circuits

The dispersion characteristics of Insulated non-radiative dielectric guides are computed using mode matching technique. From the dispersion characteristics the dielectric loss conductor loss and wave impedances are derived. Effect of metallic walls on trapped insulated image guide are also discussed. The dimensions of Insulated non radiative dielectric guide are same as that of rectangular metallic wave guide at ka band.     

Magnetostatic wave convolvers

The present paper reviews recent theoretical results, and reports initial experimental results, on the convolution of contra-propagating magnetostatic forward volume waves (MSFVWs), in the form of cw signals or time-limited cw pulses, in an epitaxial yttrium iron garnet (YIG) film. Computations of the convolver bilinearity factorF _int indicate an efficient convolution process over a wide bandwidth, with values ofF _int that are of the same order as, or better than, the reported experimental results for MSW convolution in a YIG cylindrical or plate geometry. The values of F_int determined experimentally are in excellent agreement with theory. These results are of interest to microwave system developers particularly if bandwidths of 1 GHz or larger can be realized in practice. A limiting feature of magnetostatic wave (MSW) convolvers is that the maximum delay time of a delay line that is realizable without excessive insertion loss is in the order of 0.5s. The advantage of MSW convolvers, of course, lies in their ability to perform signal processing directly at microwave frequencies, and in applications such as electronic warfare the advantageously large bandwidths would mitigate the limitations in delay time.This work was supported in part by a contract from the AIL Division of the Eaton Corporation.     

Electrodynamics of wave processes into two-connected planar wave guide structures

There are represented three configurations of two-connected planar wave-guides, two of them have small dissipations. We research theoretically and experimentally dependences of wave impedance, integration level and dissipations of proposed waveguides on their geometrical parameters and dielectric fulfillment structure. Obtained results for planar waveguide are represented and compared with results, correspondent to standard microstrip line researches.     

矩形波导中电磁波传输特性研究

本文基于功率流分别讨论了在矩形波导横截面积一定,TEm0和TMmn模式单独传输时,宽长尺寸比的最优解问题,得到了TEm0波传播时,其宽长比应趋近于0;TMmn波传播时,m＜n,仅TM12的宽长比为1;m≥n,宽长比为n/m.所得结果对矩形波导尺寸的选择和设计有潜在的应用价值.     

Millimeter wave antennas

Major advances in millimeter-wave antennas have been made in recent years, in particular in two areas. A new class of leaky-wave antennas based on open millimeter waveguides has been proposed and investigated, and substantial progress has been achieved in integrated antennas where active and passive circuits, possibly in monolithic form, are combined with the radiating elements in one compact unit. Interesting developments have taken place also in a third group of millimeter-wave antennas, that of microstrip antennas and printed circuit antennas in general. An attempt is made to summarize these developments     

Log-domain wave filters

A systematic method for designing log-domain wave filters is presented. Wave filters simulate topologically and functionally passive doubly terminated LC ladder prototype filters of low sensitivity. The design in the log-domain is based on a transposition of the signal flow graph (SFG) that corresponds to the wave equivalent of elementary two-port blocks in the linear domain, to the corresponding log-domain SFG. This is achieved by using an appropriate set of complementary operators, in order to preserve the linear operation of the whole circuit. Simulation results of a fifth-order low-pass and a fourth-order bandpass log-domain wave filter are given, using HSPICE. The proposed circuits are suitable for low-voltage operation and in high-frequency applications.     

Guided wave optics

Phenomena associated with the propagation and manipulation of light in thin-film dielectric waveguides are presently the object of considerable research effort, directed toward possible applications in communications and information processing. The theory of dielectric waveguide modes is reviewed, and the topics of directional coupling, input-output coupling, modulation, and distributed feedback laser sources are treated on the basis of coupled-mode theory. A summary of experimental results for each of the guided-wave optical phenomena covered by the theory is also presented.     

Pulsed wave interconnect

Pulsed wave interconnect is proposed for global interconnect applications. Signals are represented by localized wave-packets that propagate along the interconnect lines at the local speed of light to trigger the receivers. Energy consumption is reduced through charging up only part of the interconnect lines and using the voltage doubling property of the receiver gate capacitances. In a 0.18-/spl mu/m CMOS technology case study, SPICE simulations show that pulsed wave interconnect can save up to 50% of energy and /spl sim/30% of chip area in comparison with the repeater insertion method. A proposed signal splitting structure provides reasonable isolations between different receivers. Measured S-parameters of 3.8-mm interconnect lines fabricated through CMOS foundry showed that the distortion and attenuation of a pico second signal are much less serious than the theoretical predictions. Pulsed wave interconnect also enables time division application of a single line to boost its bit rate capacity. The use of nonlinear transmission lines (NLTL) is also proposed to overcome pulse broadening and attenuation caused by dispersion and frequency-dependent losses. Pulsed waves on an NLTL may be generated, transmitted, split and detected with components realizable in bulk and SOI CMOS technologies. Tapered NLTL can be used for pulse compression. NLTL edge sharpening abilities may be applicable for signal rise time control.     

Magnetostatic wave mixer

A new element, allowing the mixing of signals in the microwave frequency range is described. Excitation of magnetostatic waves (MSW) in the non-stationary medium has been used to modulate the carrier harmonic signal. The proper choice of the working point allows the higher harmonic products of the output frequency spectrum to be suppressed.<>     

Edge wave visualization

Scattering mechanisms that involve edge waves are addressed. The behavior of edge waves and their interaction with flat perfectly conducting plates are depicted in the time domain through a visualization of surface currents that flow on the surface, as an incident Gaussian pulse of energy washes over the surface. Viewing these surface currents allows a very clear physical interpretation and appreciation of the scattering process     

Surface wave fields and power in millimeter wave integrated dipole antennas

In this paper simple closed form expressions of surface wave fields for microstrip dipoles on grounded substrates are presented. The surface power, radiated power and radiation efficiency are calculated. It is shown that the radiation efficiency decreases with the increase of substrate electrical thickness. Hence new type antennas are needed to radiate millimeter wave because of the effect of the surface waves in substrate.     

Differential current-mode tunable wave active filters based on single-ended wave port terminators

A method for the design of differential current-mode wave active filters, which is based on the use of single-ended wave port terminators, is presented in this paper. The resulting filters are modular and very simple to design while their cutoff frequency is controlled by a dc current, giving them the ability of frequency tuning. As an example a wide-band bandpass filter is realized by cascading a low-pass and a highpass filter. The overall filter has been integrated using a standard 0.35-/spl mu/m CMOS technology.     

Medium wave skywave beams

The author discusses the advantages and drawbacks of skywaves and why they are avoided by domestic medium-wave broadcaster. He reports some results of a computer investigation of problems encountered with medium-wave antennas coupled to a skywave propagation medium. Experimental results are given showing skywave patterns for broadcasts from Alaska, one using a horizontal and the other a vertical antenna. It is concluded for these two examples that remarkable medium-wave coverage could be obtained using available frequencies     

Pseudo-elliptic slow wave line

Quasi elliptic filters are of great demand in the present day communication systems. Coupling matrix analysis of pseudo-elliptic low pass filter using conventional microstrip line is presented in this paper. The conventional microstrip line has no non-zero cut off frequency. The conventional microstrip line is transformed into a pseudo-elliptic low-pass filter using the concept of slow wave. The slow wave microstrip line exhibits pseudo-elliptic low-pass behavior with transmission zeros at finite frequencies unlike the conventional Butterworth and Chebyshev filters. The coupling matrix of the slow wave microstrip line is arrived at by using the generalized Chebyshev functions. The coupling matrix of the slow wave line is validated using the MATLAB tool box. Finally, the prototype is fabricated and the performance is measured.