新工艺实现高速、多通道数字隔离器

在一个完整信号链路中,数字隔离器起着信号隔离、电气绝缘等作用.现在的电子系统设计正面临着高速、高性能和高可靠性的挑战,而目前在信号处理链路中数字隔离器仍是相对独立的器件.因此,数字隔离器的性能对于整个系统的影响正日益受到设计人员的关注.     

一种新型宽带微波有源网络偏置电路的优化设计

利用径向传输线理论对微波有源网络的扇形偏置电路进行了分析。导出了扇形阵偏置电路的目标函数。此目标函数用于计算机辅助设计宽带微带偏置电路，取得了很好的效果。     

宽频带微波移相器的优化设计

在探讨模拟360°移相器线性调相的基础上,对微波移相器的宽频带设计进行了详尽的理论分析,建立了优化设计模型,给出了优化设计的一系列图表及曲线.设计的宽频带360°线性移相器在实验上取得了较好的效果,理论与实践符合得较好.     

一种宽带增益均衡器的设计与仿真

利用薄膜电阻加载的枝节谐振器设计了一种微小尺寸的微带均衡器子结构电路。利用CST仿真软件设计模拟了基于该结构的宽带增益均衡器,并给出了仿真结果。     

一种P波段高功率隔离器的研制

本文介绍了一种P波段隔离器的设计与实现方法,它具有低频段、大带宽、耐高功率等特点.首先,根据技术指标要求,对器件进行了结构方案设计;接着,综合分析了器件的耐功率、材料选型、工艺性等设计方法和设计思路;最后,研制出实物样机,并得到电性能实测结果,验证了设计的合理性.它的成功研制为此类微波器件的设计提供了经验与借鉴.     

Broad-Band Cavity-Type Parametric Amplifier Design

This paper tells how maximum bandwidth can be obtained from a nondegenerate parametric amplifier which utilizes a circulator. Expressions are derived for the gain bandwidth product and maximum possible gain bandwidth product. It is then shown how the Q of the cavities used for the signal and idler circuits may be kept at a minimum without degrading the noise performance of the amplifier. It is shown that best performance results when the TEM mode is used in coax, or, if waveguide is used, when the operating frequency is far away from the waveguide cutoff frequency. The diode used should have as high a self-resonant frequency as possible and the line admittance should be approximately the diode susceptance. Using a diode with a self-resonant frequency at the idler frequency will be seen to give optimum performance. This paper also discusses double tuning the signal circuit to achieve broader bandwidths. In this case, the addition of the second tuned circuit will be seen to give much broader bandwidths than one would expect from conventional filter theory. Two sample amplifiers are considered and their bandwidths calculated. The effect of double tuning one of the amplifiers is then considered.     

Broad-Band Coaxial Choked Coupling Design

Equations and curves are presented to predict the frequency bandwidth of coaxial choke couplings in terms of the choke parameters. Choke couplings discussed are those applicable to rotary joints and dc isolation units.     

Design of a Full Waveguide Bandwidth High-Power Isolator

An analysis of the microwave fields in rectangular waveguide indicates that circular polarization of the H-vector components exists at two planes only and the location of these planes is frequency dependent. Also, an examination of Kittel's theory reveals that resonance in ferrites can be made to occur at different frequencies for a constant value of dc magnetic biasing field provided the ferrites are characterized by different values of saturation magnetization. These two effects have been used concurrently in the design of an X-band waveguide isolator for operation over a 45 per cent bandwidth, and at high power levels. The theory underlying the design of this isolator is presented. Included is a treatment of the parameters which affect the isolator design. Finally, an operative isolator is described and its experimental characteristics are reported.     

宽带同轴固定衰减器的设计

介绍一种微波宽带同轴固定衰减器的设计方法,为了满足器件的指标要求和可生产性,主要从结构设计方面做了充分的论述,并通过了测试和实验验证。     

Design of a Broad-Band 4-Bit Loaded Switched-Line Phase Shifter

A 4-bit p-i-n diode switched-line phase shifter was fabricated for use in the 2.0- to 4.0-GHZ frequency range. Extremely good phase characteristics were easily obtained over two octaves by employing a resistive loading technique to eliminate resonance problems. A single bit was modeled and analyzed on a computer from 1.5 to 6.0 GHz. Test results of a microstrip realization of this bit, which correlates well with the computer model, are presented. A unique compatible driver used with the phase shifter, and the microstrip fabrication process used in constructing the phase shifter are also presented.     

A Broad-Band Amplifier Output Network Design

An analytic design method for a lossy gain-compensating network is presented and the advantages of lossy networks are discussed. Examples of two-stage amplifiers using FET's and bipolar transistors are presented to show the feasibility of this particular network in low power amplifier designs. These amplifiers obtain gains of 15.4+-0.5 dB with a 2.5-dB maximum noise figure in the 4.0--6.0-GHz frequency range and 16.5+-1.2 dB with a maximum input VSWR of 1.78:1 over the 1.0--2.0-GHz frequency range, respectively.     

Design of a Switched Broad-Band Communications Network for Interactive Services

The congestion in broad-band communications networks resulting from the increased demand for interactive services is considered. It is shown that services such as a video library could not be provided to the majority of subscribers in a conventional CATV network. A design is developed for a space division multiplex broad-band network which can be expanded at minimum cost to meet an increasing demand for interactive services. The network contains two signal distribution networks: a cablecast system similar to the Rediffusion system, and a switched communication network providing point-to-point circuits for both one-way and two-way services. All broad-band signals are transmitted to the subscribers in the 1- to 10-MHz spectrum, permitting the use of twisted pair video cables and a minimum number of cable amplifiers. The broad-band cable network (BCN) is organized around 15 local switching exchanges and one central exchange. Multipoint switches in local exchanges under wired-logic circuit control connect individual subscriber communication lines to any channel. Crosspoint matrix switching groups in the local and central exchanges connect communication circuits in the broad-band communication network under programmed computer control. This network is accessed via links terminating on one channel of the multiposition switches. Per-subscriber costs are estimated to be 190 dollars for a cablecast system serving 3800 subscribers. Additional expenditures per subscriber of 40 dollars for fixed costs and 40 dollars for variable costs would provide interactive services. The range of interactive services provided would be extremely flexible, including both one-way video library service and point-to-point two-way communications.     

Broad-Band Stub Design (Correspondence)

Mr. Muehe's results for broad-band stubs, while going beyond that of previous investigators, are similar to my design curves published earlier without detailed derivation. The main difference is that my curves were based on a formula involving the bandwidth as defined by the lowest and highest frequencies of zero reflection. Mr. Muehe's analysis is therefore superior to my simpler approach: my design curves erred on the safe side in predicting a slightly smaller bandwidth.     

一种新型偏振相关磁光隔离器的设计

该文介绍了一种新型的光纤型法拉第磁光隔离器设计方法,利用液相外延制备的单晶石榴石(BiTm)3(GaFe)5O12膜作为法拉第转子,通过对光路结构的改进设计,有效降低了光隔离器体积和所需饱和外场。当外磁场H=47×103 A/m时,法拉第旋角可达到45°@1 550 nm,光吸收系数为15 cm-1 @1 550 nm,光透射率为85%@1 550 nm,整体满足设计要求。     

一种微型宽带光隔离器的设计研制

文章提出了一种小型化光隔离器的设计方案,通过理论分析其实现原理以及各个光学参数,并由实验证实了该方案的有效性。设计结果表明,在保证获得优良参数情况下,采用该方案能使光隔离器结构更紧凑,且有效降低其成本和装配难度。通过1／4波片及全波片对法拉第旋光片的旋光色散特性补偿后,可使该器件的隔离度参数随波长变化不敏感,此外,由于采用对称的光路设计,该方案的偏振模色散理论值为0,无需额外补偿。     

Automated Design of DC-Coupled Broad-Band Amplifiers Monolithic

A design automation program has been written to optimize the design of dc-coupled monolithic broad-band amplifiers. This program adjusts dc conditions, device geometry, and all passive elements to obtain the maximum small-signal bandwidth consistent with specified low-frequency gain and quiescent power dissipation. The principal features of the program are a frequency-response analysis subroutine based on a nodal admittance matrix formulation, a precise response sensitivity analysis using the adjoint network, and an optimization subroutine based on the Fletcher-Powell algorithm. Two complete design examples, based on the series-series feedback triple and series-shunt feedback pair, are presented. For typical integrated-circuit processing, a maximum bandwidth on the order of 100 MHz is obtained for these designs with a voltage gain of 34 dB and 96-mW power dissipation.     

Design of Broad-Band GaAs FET Power Amplifiers

A direct systematic approach to designing broad-band GaAS FET power amplifiers for optimum large-signal gain performance is described. Assets of this approach include its accuracy in predicting large-signal amplifier performance and its basic simplicity. The implementation of the technique is facilitated by having to measure large-signal device bebavior at only one single frequency. The practicability of the method is demonstrated through comparisons between measured and predicted results.     

Broad-Band Design Techniques for Transimpedance Amplifiers

In this paper, a novel bandwidth enhancement technique based on the combination of capacitive degeneration, broad-band matching network, and the regulated cascode (RGC) input stage is proposed and analyzed, which turns the transimpedance amplifier (TIA) design into a fifth-order low-pass filter with Butterworth response. This broad-band design methodology for TIAs is presented with an example implemented in CHRT 0.18-mum 1.8-V RF CMOS technology. Measurement data shows a -3-dB bandwidth of about 8 GHz with 0.25-pF photodiode capacitance. Comparing with the core RGC TIA without capacitive degeneration and broad-band matching network, this design achieves an overall bandwidth enhancement ratio of 3.6 with very small gain ripple. The transimpedance gain is 53 dBOmega with a group delay of 80plusmn20 ps. The chip consumes only 13.5-mW dc power and the measured average input-referred noise current spectral density is 18 pA/radicHz up to 10 GHz     

高性能X波段铁氧体隔离器设计

铁氧体隔离器在微波系统中具有重要作用。基于YIG铁氧体基片,采用低场工作模式和双Y圆盘中心导体结构,设计了一款X波段隔离器,通过三维电磁仿真软件HFSS仿真分析了不同参数对隔离器性能的影响并进行了优化,进行加工测试。测试结果表明,在9.2~9.8 GHz的频率范围内,电压驻波比(VSWR)<1.1 d B,插入损耗<0.5 d B,隔离度>23d B,所设计的隔离器达到了较高的性能指标,符合微波射频电路高频段、高性能的要求。