Probability of Error in Binary Communication Systems with Causal Band-Limiting Filters--Part I: Nonreturn-to-Zero Signal

Upper and lower bounds to probability of error in binary communication systems with intersymbol interference are presented. Closed-form formulas are given for systems with filters having a finite number of lumped elements. Explicit results are given when the filters are Butterworth filters of orderN = 1, 2,..., 10. Four systems are considered: with a sample detector (SD), with an integrate-integrated-and-dump detector (IDD), with a filter in receiver only, and with filters in receiver and transmitter. The transmitted signal is assumed to be of the nonreturn-nonreturn-to-zero (NRZ) form.     

Analysis of a horn-lens TEM antenna

Matching and radiation characteristics of a horn-lens TEM antenna are studied theoretically and experimentally in an ultra-wide frequency band. Theoretical results are obtained by means of electromagnetic modeling on the basis of the finite-element method. Antennas with different geometries of the lens and different methods of excitation of the TEM horn are considered. Direct excitation by a coaxial line and excitation with the use of a smooth transition from a coaxial line to a stripline are studied. The results of calculations are compared with experimental results.     

Measurement and Simulation of Time Response of Printed Modal Filters with Broad-Side Coupling

A principle of modal filtering and an asymmetric modal filter with broad-side coupling are presented. Prototypes with different parameters are developed and fabricated. Experimental measurements and computer simulation are performed for the time response to a pulse with a duration of about 1 ns. It is shown that the simulated results are in agreement with the experimental data. Attenuation of the input pulse by a factor of 5 is demonstrated for the modal filter with optimal parameters for a 50-Ω circuit.     

Design of Surface Wave Delay Lines with Interdigital Transducers

Design aspects and tradeoffs are presented for nondispersive, analog Rayleigh wave delay lines with interdigital transducers. Design procedures are based on a one-dimensional piezoelectric transducer model whose applicability has been confirmed by experimental data taken on transducers operating at 100 MHz. For transducers with series inductive tuning, optimum aperture and number of interdigital periods are given for several attractive piezoelectrics, such that insertion loss and phase dispersion are minimized while bandwidth is maximized. High-triple transit suppression designs are given for bidirectional transducers, implying some sacrifice in insertion loss. Using directional transducers, low insertion loss and high triple transit suppression are achieved simultaneously at some sacrifice in bandwidth. Finally, two approaches are given for making with presently available piezoelectrics, bandwidths higher than those attainable with a single tuning inductor. The first of these uses a coupled resonator electrical matching network, while the second employs a transducer with graded periodicity.     

Surface waves on a grounded dielectric slab covered by a resistivesheet

Surface wave propagation in a grounded dielectric slab covered with a resistive sheet is examined. Transcendental equations are derived for each polarization and are solved using iterative techniques. Attenuation and phase velocity are shown for a representative geometry. The results are applicable to both a grounded slab covered with a resistive sheet and an ungrounded slab covered on each side with a resistive sheet     

Interaction of Electromagnetic Waves with Cylindrical Plasma

Exact numerical solutions are given for the interaction of a plane, electromagnetic wave with a cylindrical plasma. The incident wave is normal to the plasma axis and both TE and TM polarizations are considered. The electron density profile is represented by a Gaussian curve consistent with flow-field calculations for wakes and jets. Transmitted and scattered amplitudes are evaluated as functions of the polar angle and plasma parameters. The data are compared with previous theoretical and experimental work. [17],[18] Parabolic electron density profiles are also investigated and contrasted with the Gaussian results. The sharp cutoff in a parabolic profile has a significant effect on the electromagnetic interaction. Applications to microwave diagnostics are discussed including a new bistatic method.     

Propagation characteristics of dielectric-rod-loaded waveguides

A general technique for calculating the propagation characteristics of a waveguide with arbitrary cross-sectional shape loaded with a circular dielectric rod is presented. The waveguide fields, which are represented as a sum of functions satisfying the homogeneous Helmholtz equation and the boundary conditions at the rod surface, are point-matched at the surface of the waveguide. Numerical examples of a rod centered in a square guide and off center in a circular guide are given, and results for a rod centered in a rectangular cavity are compared with measured data     

An Simple Enumeration of All Minimal Cutsets of an All-Terminal Graph

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Quantum functional devices: resonant-tunneling transistors,circuits with reduced complexity, and multiple valued logic

Recent advances in the area of quantum functional devices are discussed. After a discussion of the functional device concept, resonant-tunneling bipolar transistors (RTBTs) with a double barrier in the base region are described. Design considerations for RTBTs with ballistic injection and the first observation of minority-electron ballistic RT are presented. RTBTs using thermionic injection and exhibiting a high peak-to-valley ratio at room temperature in the transfer characteristics are also described. Multiple-state RTBTs and their DC and microwave performance are then discussed. Circuit applications of RTBTs also are discussed. It is shown that RTBTs allow the implementation of many analog and digital circuit functions with a greatly reduced number of transistors and show considerable promise for multiple-valued logic. Experimental results on frequency multipliers and parity bit generators are presented. Analog-to-digital converters are memory circuits are also discussed. Two novel superlattice-base transistors are reported. Negative transconductance is achieved by suppression of injection into minibands. Gated quantum-well RT transistors are also discussed     

On-Chip Power Distribution Grids With Multiple Supply Voltages for High-Performance Integrated Circuits

On-chip power distribution grids with multiple supply voltages are discussed in this paper. Two types of interdigitated and paired power distribution grids with multiple supply voltages and multiple grounds are presented. Analytic models are also developed to estimate the loop inductance in four types of proposed power delivery schemes. Two proposed schemes, fully and pseudo-interdigitated power delivery, reduce power supply voltage drops as compared to conventional interdigitated power distribution systems with dual supplies and a single ground by, on average, 15.3% and 0.3%, respectively. The performance of the proposed on-chip power distribution grids is compared to a reference power distribution grid with a single supply and a single ground. The voltage drop in fully interdigitated and fully paired power distribution grids with multiple supplies and multiple grounds is reduced, on average, by 2.7% and 2.3%, respectively, as compared to the voltage drop of an interdigitated power distribution grid with a single supply and a single ground. The proposed power distribution grids are a better alternative to a single supply voltage and a single ground power distribution system. On-chip resonances in power distribution grids with decoupling capacitors are intuitively explained in this paper, and circuit design implications are provided. It is also noted that fully interdigitated and fully paired power distribution grids with multiple supply voltages and multiple grounds are recommended to decouple power supply voltages.     

On The Problem of Using Guard Traces for High Frequency Differential Lines Crosstalk Reduction

In this paper, the problem of using guard traces for reducing crosstalk between differential transmission line pairs is investigated, both experimentally and by full-wave electromagnetic (EM) simulations. Different cases of differential lines crosstalk are treated with and without guard trace separation between the differential line pairs. Coated microstrip printed circuit board test structures including thru-reflect-line calibration standards are designed and fabricated on a high frequency laminate material, allowing direct measurement of crosstalk between adjacent differential line pairs in the absence and in the presence of guard traces stitched with vias of regular spacing. The test structures are characterized with mixed-mode scattering parameters using a physical layer test system. Different configurations (of differential line pairs) without guard trace, with floating guard traces (which are terminated and nonterminated) and with a solid guard trace separation are investigated using a High Frequency Structure Simulator (a commercial full-wave 3-D EM simulation tool). The experimental data are compared with the simulation results, and some conclusions and guidelines on the effect of guard traces for alleviating crosstalk between differential transmission lines are presented     

带变反射率耦合输出镜的连续高功率Nd：YAG激光器的研究

分析了具有变反射率耦合输出镜（ＶＲＭ）的热透镜谐振腔的光束传输特征，研究了ＶＲＭ的耦合输出及对高功率固体激光光束的选模作用，实验结果验证了理论分析并得到连续波１８０Ｗ，光束参数乘积（远场发散角半角×近场光束半径）为６．２５ｍｍ·ｍｒａｄ的高亮度激光输出。     

Network Analysis of Millimeter-Wave Omnidirectional Periodic Dielectric Rod Antenna with Arbitrary Grating Profile

The radiation characteristics of the omnidirectional periodic circular dielectric rod leaky-wave antenna with arbitrary grating profile are investigated by the network method combining with staircase approximation. In the analysis, the arbitrary grating profiles are transformed to a multilayer rectangular periodic structure, which is represented by a radial transmission line with a series current source. As a result, the calculations are greatly simplified and the effects of grating profile on the performance of the grating antenna are systematically studied in a very efficient way. Some useftil guidelines for the design and fabrication of the omnidirectional dielectric grating antenna are thereby suggested.     

两镜系统分析

本文根据三级像差理论,讨论了满足系统为会聚光路、系统遮拦比|α|<1两个条件的两镜系统,分析了以消球差S_1=0为初始条件,同时校正其余像差系数S_(II),S_(III)的系统。对在不同非球面系数条件下,主镜、副镜的面形以及比较半径R_1,R_2随遮拦比α和放大率β的变化作了分析,并总结了现有已命名的经典系统。     

Additional Losses in the Damper Winding of Large Hydrogenerators at Open-Circuit and Load Conditions

Large salient-pole synchronous machines are typically equipped with a damper winding. At steady-state conditions, parasitic voltages are induced in the damper bars which lead to a current flow with associated power losses. This paper describes an analytical algorithm for the calculation of currents and corresponding losses in the damper winding. The presented method is based on an equivalent network of the damper winding containing all the bars of a repetitive section of the machine. The inductances are calculated with an air-gap permeance model. Contrary to similar existing approaches, the induced damper-bar voltages are computed using a numerical integration. This allows more precise results when it comes to higher harmonics. In order to validate the analytical computation, the results are compared with the results of 2-D transient finite-element studies and with a conventional analytical method based on the d-and q -axis equivalent circuits of the machine.     

The Susceptance of an Annular Metallic Strip in a Circular Waveguide with Incident TE/sub 01/ Mode

The principal aims of this paper are twofold: 1) to solve the problem of the scattering of a thin, perfectly conducting aonular strip suspended in a multimodal circular waveguide in which any number of TE/sub 0n/ modes can propagate, and with the aid of this result, 2) to give the susceptance of the thin annular strip in monomodal circular guide with an incident TE/sub 01/ mode. These are treated with a variational approach. Applying the appropriate Green's functions to the continuity equations for the transverse electric field yields a variational expansion for the scattering matrix elements. This is treated with a Rayleigh-Ritz procedure and matrix methods. Curves of normalized susceptance as a function of the free-space wavelength and the size of the annular metallic strip are shown. These results are in good agreement with experimental data. Tables of the scattering coefficients for a typical wavelength versus strip size are also included.     

毫米波缝隙天线的三维非硅微加工制造技术

讨论了面向毫米波缝隙天线集成制造应用的三维非硅微加工技术方案,重点解决多种材料兼容、多层复杂微结构集成和大悬空高度等独特难题。针对天线器件中金属和介质材料的结合,提出了加法工艺、减法工艺以及一种通用型图形化微加工工艺,其中通用型图形化工艺为各种非硅薄膜材料在MEMS体系中的灵活运用创造了条件;为了实现多层复杂微结构的加工,提出工艺整合和工艺兼容性设计,针对天线器件中的悬空结构对牺牲层工艺进行了研究;最后以一种单向宽带毫米波平面缝隙天线为例,阐述其具体工艺流程,验证了上述工艺的可行性。     

CAD models for multilayered substrate interdigital capacitors

Conformal mapping-based models are given for interdigital capacitors on substrates with a thin superstrate and/or covering dielectric film. The models are useful for a wide range of dielectric constants and layer thicknesses. Capacitors with finger numbers n⩾2 are discussed. The finger widths and spacing between them may be different. The results are compared with the available data and some examples are given to demonstrate the potential of the models     

Equivalent Circuits for Discontinuities in Balanced Strip Transmission Line

Theoretical formulas are derived for the equivalent circuit parameters of a variety of discontinuties in balanced strip transmission line. These formulas are simple in form and are obtained by employing a small aperture procedure or a Babinet equivalence procedure in conjunction with an approximate model of the line. The results for a number of discontinuities are presented and comparison is made with the available measured data.