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本文介绍了运用电话机集成电路TEA1062实现消侧音的原理及应用,并对实际使用中的稳定性问题进行了分析和有效地解决,实现消侧音电路的高质量、低成本. 相似文献
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一、电子电话机消侧音电路分析 1993年邮电部通信司印发了“普及型电话机优化电路”。该优化电路共有四种电话机电路,具有广泛的代表性。侧音参考当量是电子电话机的一个重要质量指标。对侧音电路的分析有利于对电话机整机电路的理解,对维修和生产有一定的帮助。下面对优化电路中两种不同形式的消侧音电路进行分析。 相似文献
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按键话机中的几种消侧音电路 总被引:1,自引:0,他引:1
在按键话机中,常采用以下几种电路来消侧音.现简介如下.一、变量器消侧音其电路如图1所示,在理想情况下,Z_L和平衡网络阻抗相等,线圈Ⅰ和线圈Ⅱ匝数一样.所以线圈Ⅰ和线圈Ⅱ中的话音电流i_1和i_2大小相等,但方向相反,产生的磁通方向也相反,因而相互抵消,线圈Ⅲ中不产生感应电动势,从而是达到消侧音的目的. 相似文献
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小波变换在雷达回波信号消噪处理中的应用 总被引:8,自引:0,他引:8
分析了雷达回波信号中所含噪声的特点、小波变换的原理,在此基础上着重论述了小波变换应用于雷达回波信号消噪处理的原理和方法,并从仿真试验中验证:将小波变换应用于雷达回波信号的消噪处理,可以极大地改善回波的信噪比,提高目标信号的可检测性. 相似文献
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当今国内的医院护理系统的发展现状,采用MSP430单片机与DTMF技术设计医院呼叫对讲系统,该系统以MSP430F149单片机作为控制核心,采用DTMF信号收发电路、DTMF信号编译码电路、振铃检测电路和显示电路等外围电路,通过进行硬件模拟实验和MATLAB软件仿真实验,验证了该系统的可行性和可靠性,可以实现拨号通话、显示信息、广播和护理级别设置等功能。该系统的设计简洁,主机芯片MSP430F149实现了低功耗,系统安装方便简单而且易于维护,成本比较低,具有较高的实用价值。 相似文献
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V. Belevitch 《Circuits, Systems, and Signal Processing》1983,2(1):99-117
The anti-sidetone telephone circuit is a frequency-independent passive reciprocal 3-port whose scattering matrix between three prescribed resistive terminations (transmitter, receiver, line) meets a certain specification. In their 1920 paper, Campbell and Foster (CF) showed that the prescribed 3-port can be realized as a lossless 4-port consisting in two 3-winding transformers closed on one resistance (the balancing network). If one (two) relations are imposed between the terminating resistances of the 4-port, realizations involving a single 3-winding (2-winding) transformer are available, and the resulting 136 (38) distinct realizations have been listed by CF. In this paper, we reestablish the CF-results (which were stated almost without proof in their paper and have never been rediscussed in the literature) and present a genetic classification of their 136 + 38 circuits. Recently, a realization of the anti-sidetone 3-port containing more than one internal resistance (in addition to the balancing network, a light-emitting diode serves to illuminate the dial) has been described by D. R. Means; in this paper, we present a complete characterization of that wider class of circuits. 相似文献
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Described are the fundamental design principles for binary-logic circuits using a highly functional device called the neuron MOS transistor (νMOS), a single MOS transistor simulating the function of biological neurons. To facilitate logic design employing this transistor, a graphical technique called the floating-gate potential diagram has been developed. It is shown that any Boolean functions can be generated using a common circuit configuration of two-stage νMOS inverters. One of the most striking features of νMOS binary-logic application is the realization of a so-called soft hardware logic circuit. The circuit can be made to represent any logic function (AND, OR, NAND, NOR, exclusive-NOR, exclusive-OR, etc.) by adjusting external control signals without any modifications in its hardware configuration. The circuit allows real-time reconfigurable systems to be built. Test circuits were fabricated by a double-polysilicon CMOS process and their operation was experimentally verified 相似文献
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本文介绍了通信技术和通信电路的发展情况,论述了通信技术和通信电路与通信LSI/VLSI发展的密切关系以及通信电路技术的特点;并通过实例说明通信LSI/VLSI中典型的电路和技术。 相似文献
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Nielsen L.S. Sparso J. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1999,87(2):268-281
This paper addresses the design of asynchronous circuits for low power through an example: a filter bank for a digital hearing aid. The asynchronous design re-implements an existing synchronous circuit which is used in a commercial product. For comparison, both designs have been fabricated in the same 0.7 μm CMOS technology. When processing typical data (less than 50 dB sound pressure), the asynchronous control and data-path logic, an improved RAM design, and by a mechanism that adapts the number range to the actual need (exploiting the fact that typical audio signals are characterized by numerically small samples). Apart from the improved RAM design, these measures are only viable in an asynchronous design. The principles and techniques explained in this paper are of a general nature, and they apply to the design of asynchronous low-power digital signal-processing circuits in a broader perspective. In fact, this understanding is one of the contributions of the paper. Finally, the paper can be read as an example-driven introduction to asynchronous low-power design 相似文献
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The philosophy, mechanics, and syllabus of a unified sophomore course in nonlinear electronic circuits are offered as a possible solution to the dilemma, long faced by teachers of electronic circuit theory, of a decreasing amount of time in which to present circuits containing an increasing variety of nonlinear electronic devices. The logic and feasibility of teaching the unified principles of nonlinear circuit analysis which are independent of the devices and their internal physical principles of operation, and which require no prerequisite other than elementary calculus, are illustrated with typical examples of various practical large signal electronic circuits actually taught in the course. The necessity to teach only a few fundamental unifying concepts and techniques, and the high motivational value of the proposed approach are shown to be the overriding factors which led-to-the success of this sophomore course at Purdue University. 相似文献
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de Moraes R.M. Anlage S.M. 《IEEE transactions on circuits and systems. I, Regular papers》2004,51(4):748-754
We investigate the combined effect of rectification and nonlinear dynamics on the behavior of several simple nonlinear circuits. We consider the classic resistor-inductor-diode (RLD) circuit driven by a low-frequency (LF) source when an operational amplifier with negative feedback is added to the circuit. Ultra-high-frequency (UHF) signals are applied to the circuit, causing significant changes in the onset of LF period doubling and chaos. Measurements indicate that this effect is associated with a dc voltage induced by rectification of the UHF signal in the circuit. The combination of rectification and nonlinear circuit dynamics produce qualitatively new behavior, which opens up a new channel of radio frequency interference in circuits. 相似文献
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This paper presents a new method and circuit for the conversion of binary phase-shift keying (BPSK) signals into amplitude shift keying signals. The basic principles of the conversion method are the superharmonic injection and locking of oscillator circuits, and interference phenomena. The first one is used to synchronize the oscillators, while the second is used to generate an amplitude interference pattern that reproduces the original phase modulation. When combined with an envelope detector, the proposed converter circuit allows the coherent demodulation of BPSK signals without need of any explicit carrier recovery system. The time response of the converter circuit to phase changes of the input signal, as well as the conversion limits, are discussed in detail. 相似文献
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在硬件实验研究的基础上,建立一种环形蔡氏电路,简述其工作原理及其特点。在此基础上提出用环形蔡氏电路实现混沌反馈调制的一种语音保密通信方案,分析了该方案的同步原理,讨论了发送端和接收端电路参数匹配情况下的同步收敛特性,设计了硬件实验电路,进行了语音混沌保密通信的硬件实验研究,给出了实验结果。 相似文献