外文翻译---波形合成电路的分析与设计

附录二：英文原文The Analysis and Design ofWaveform GeneratorXue lian ,Wang Fan ,Zheng Jin-faEngineering and CommerceCollege, South-CentralUniversity for Nationalities, WuhanHubei430065Abstract: In this paper, the sinusoidal waves in different frequency were synthesized into square wave according to the method of Fourier series. Firstly, the needed sinusoidal waves were achieved through the square wave generation circuit, the frequency division circuit and the filter circuit; then, after the sinusoidal waves’ phase position were shifted and synthesized, the square wave was generated. This circuit in this method was more cheaper than other circuits (eg: DDS). Keywords: Waveform Generator;SinusoidalWave;Filter;Phase PositionShift1 waveform synthesis system overviewThis is designed to simulate the process of signal synthesis. For a square wave signal by Fourier series spread knowable, it can decompose the amplitude of the more specific for unlimited odd harmonics, so in turn as long as infinite multiple odd harmonic component, the amplitude and the harmonic proportion in a particular superposition, also will certainly get a square wave signal. This paper is the simulated the base wave and three harmonic harmonic component synthesis process of square wave signal. Theoretically speaking, the harmonic components, synthetic waveform will more close to the standard square bobo shape.This system begin with a square wave oscillator to generate a frequency of 60KHz pulse signal, again into separate frequency device 10KHz to get a frequency for handling of square wave signal and a frequency of square wave signal for 30KHz, then respectively through the filter processing for the sine signal and 30KHz 10KHz to close-spaced 10KHz sine wave as base wave component, 30KHz sine wave as three times, through modulation circuit harmonics of adjust them respectively in fengfeng value, can satisfy 2V 6V and Fourier series spread coefficient ratio; Put the sine signals into 10KHz to phase shifter phase adjuster, and after 30KHz sinusoidal signal together into addition circuit synthesis, namely complete signal stack. It can be inferred that the output signal is adder an approximate square-wave signal, and frequency for probably 10KHz. System unit circuit as shown in figure 1 below.Figure 1 system structure diagram2 the hardware circuit design2.1 square wave generating circuit designAccording to the above analysis, the 60kHz should be produced for pulse frequency. Square wave can use digital circuit generation, also can use analog circuits produce. As digital circuits produce waveform amplitude, needs to be smaller using simulated circuit to amplify; And compared with mixed-signal circuit pure analog circuits to complex, therefore, in this the paper only with analog circuits to generate square wave. The basic principle is: through the voltage comparator produce high level; Through the feedback loop and delay link to the electric frequency periodically height variations. Principle chart as figure2shows, diagram hysteretic comparator output voltage, threshold voltage; Oscillation period for. Through calculating formula by cycle that change, C, R1 ifss can be obtained with R2 ratio required pulse frequency. But this several variables in actual circuit will be some constraints, in choosing device parameters through actual adjustment should be determined. Select devices, it is suggested that resistance, so that circuit using metal film resistors the heat generated by the noise is small; Choose op-amp should consider when it's passband, passband more hours, it is difficult to achieve square-wave requirements, so we chose the frequency performance was good OPA820 op-amp.Front generated for square can't use, this latter stage, still need to pass the follow-up processing, should first except negative voltage isolation, here with a diode, so after diode for the voltage after subtracting tube voltage half before diode pressure drop. Thus square wave amplitude will more small, in order to achieve the minimum separate frequency circuit requirements, should be the voltage waveforms were pressurization. In proportion with pressor circuit USES amplifier, get the voltage amplitude moderate. Then after the voltage level for use, but in order to reduce load after each level circuit, the influence of wavelet produce circuit with load ability raise circuit, finally take a shot extremely follow device. To this, square wave generator can be expected to reach, could plug in the latter stage circuit.Figure 2 square wave generating circuit principle diagram2.2. Points frequency circuit designThis points to the former stage frequency circuits are produced, into a square 60KHz 390v for 1/2, frequency respectively. 30KHz And the square wave signal 10KHz. This treatment can easily think of using digital counter solve. The counter is commonly used sequential circuits to pulse, it not only can count, can also used for the points frequency, timing, produce beats pulse, etc. This paper use of its points frequency characteristics, a N disables counter can will it input clock signal, points for occupies emptiescompared frequency for 1 / N, frequency for input signal 1 / N output the clock signal. So in order to get the 30KHz square wave signal, the 60KHzsquare can be as the clock signal, access a secondary system, the output to a counter 390v for 1/2, frequency of square wave signal 30KHz. But for the square wave signal acquisition 10KHz, can let 60KHz square wave signal through a ternary counter, corresponding to output a occupies emptiescompared to 1/3, frequency of square wave signal for 20KHz, then the signal as the input signal, access a binary counter, you will get a 390v for 1/2, frequency for the10KHz square. The 60KHz pulse signal coming through three digital counter processing, gain satisfaction 1/2 390v requirements of 30KHz 10KHz and pulse signal.For digital counter choice is the key to realizing points frequency. If using common integrated counter 74LS \ HC163, such as (74LS \ HC161) constitute the counter, required disables 390v will appear uncertain situation, need separate frequency, adding in 390v regulating circuit, which makes the circuit is not stable and structure is more complex. And use trigger level could be behind the counter 390v good control, so the system USES a JK flip-flop composition counter, T flip-flop and D flip-flop also can choose. Then need to consider the choice to TTL and COMS device, because the system to treat signal in frequency 10KHz above all, if digital devices is easy to cause the conversion rate is too low counter can not work normally, the output signal distortion, so this paper chose conversion rate faster TTL devices. Final determination by two 74LS109 (double integration JK flip-flop) cascade form a ternary counter and two secondary system counter. Points frequency circuit fig.03 shows.Figure 3 points frequency circuit principle diagram2.3 filter and modulation circuit designFilter circuit 10KHz mainly completes 10KHz sine wave, 30KHz square to the transformation of 30KHz sine pulse to. Ideal square wave is contains all the odd frequency components, as long as the signal through specific center frequency of frequency selective network, very easy to obtain the required frequency sine wave. Considering the effect of grade synthetic after, this system directly choose the integrated bart hepworth fourth-order low-pass filter, simply switched capacitor TLC04ID appropriate choices the chip 1, 2 wide capacitance resistance can determine the filtering frequency selective of center frequency, formulas for the f = 1/1.69 RC. This filter order number is higher, frequency selective effect is good, can get the corresponding frequency better sine wave.If the yankees 10KHz sinusoidal signal as 30KHz sine wave, three times as a signal of harmonic,synthetic a 10KHz by square wave signal, then Fourier decomposition knowable, 30KHz 10KHz sinusoidal signal and the extent of the sine signals for 1:3 than needed. Because the former stage two sine signal filtered in fengfeng value is required for 5V, both by the 30KHz 10KHz and amplitude circuit of sine wave 6V respectively in fengfeng value for adjustment and 2V.For the sine signals, need 10KHz from fengfeng value 5V 6V, so to boost processing operation circuit whetherisolated selects the proportion. And for 30KHz sinusoidal line number from fengfeng value 5V, need to, so the antihypertensive treatment 2V chose simple resistance points after, to prevent voltage circuit of the resistor network level circuit influence, plus a voltage behind need comparators. The operation circuit in the attenuation, because the sine separate frequency filtering line number after all contains 2.5 V dc component, if direct capacitive coupling effect by every straight, this paper adopts the bad amplifier single power supply in isolation, after can be reached capacitance straight requirements and the large pendulum space signal. For single power supply amp, need in signal input plus bias circuits, the resistance bias is adopted. For the selection of operational amplifiers, it is LM358 can meet the requirements. Treatment can output excluding dc component 10KHz fengfeng value of 30KHz 6V sine signals and 2V sine signals in fengfeng value. As shown in figure 4 10KHz sinusoidal voltage regulation circuit shown.Figure 4 filter and modulation circuit2.4 move and addition circuit designIn order to strengthen the synthetic effect, need to treat synthetic signal phase shifting processing. Because analog synthesis signal only two, so just click on one of the signal can be adjusted. This paper introduces the design of 10KHz sine signals in the phase adjuster phase shifting circuit. By a RC network and a voltage followed sensor into the RC network, including by large resistance (R 100K adjustable, makes the signal phase in 30 °~ 90 can °range adjustment, voltage comparator to prevent the latter stage of the phase shifting circuit circuit interference.Addition to finish last is that the circuit of signal synthesis. Because the system in the former stage of the signal amplitude ratio has adjust appropriate and circuit amplification operations in addition, no fixed proportion of input and output signal circuit amplitude adjustment, so here are the simplicity of a single integrated amp LM358 constitute addition circuit can well satisfy synthetic requirements. As shown in figure 5 shows addition circuit.Figure 5 addition circuit2.5 measurement circuit designThe measurement circuit is used for measuring system of internal all sine signals, which is separate from the RMS ahead of a wave synthesis circuit happened digital measurement unit. RMS is characterization of the ac signal amplitude is an important parameter for sine signal, the RMS for its peak / 2, i.e. only if the peak namely can get sine wave get their RMS. So in the measurement of the system as a circuit, let sine signals obtained through a peak detection circuit and the peak, its peak appears as a relatively constant straight flow, again this straight flow through the AD into the corresponding digital quantity, into SCM processing, namely the RMS, such as signal with LCD display. To lastFor peak detection circuit design, because the peak in 2 are sinusoidal wave between 6V, to a larger extent to directly through the most simple, so a diode and capacitance series circuit, which diode rectifier role play half wave, and capacitance is keep peak voltage. Ideally if diode conduction voltage of 0V, then signal peak can accurately performance, and the actual in capacitance of the diode's conduction pressure drop not negligible, crunches the peak voltage equals conduction pressure drop and the original signal peak, this also is the measurement circuit in the main error, so the measurement circuit adopts the following measures to overcome this error: (1) choose conduction pressure drop of smaller diode (ge tube, 1N5189);(2) using software compensation, decrease diode conduction pressure drop. Capacitance the ceramics capacitor can choose 105. Peak check circuit figure 6 shows.AD chose successive comparison type, which has meet the advantages such as high speed, low consumption, eight precision measurements of the enough to satisfy the design requirements. Measuring signal amplitude 3V only in 1 ~ between only one range, so measurement (0 ~ 5V) can complete, will meet the positive reference voltage input termination VCC, its negative reference voltage grounding can. SCM chose AT89C51, in dealing with AD transform results, the program adopted average filtering algorithm, so can reduce the error, procedures set AD turned to the decimal data retention. Finally SMC162 with LCD display of RMS data given.Figure 6 test circuits3 system functional testingCompleted by two power system current supply for a + 5v respectively, the single power and a + 5v double power supply. Power supply reference each module circuit analysis.By above each function module circuit can complete this system. The Chinese wave to create, produce 60KHz 3v circuit, the peak of square wave, through two separate frequency circuit the signal frequency measured respectively, 30KHz and 10KHz are 5-v square-wave peak; In through a low-pass filter to get 30KHz and 10KHz, are 5-v sine wave peak; Two signal amplitude modulation circuit by respectively after treatment 30KHz corresponding 6V 10KHz corresponding 2V,; Phase shifting to 10KHz to after two circuit fine-tuning signal into synthesis circuit, will the out-port USES an oscilloscope checked to see observed fong as shown in figure 7 difform.Finally, using measuring circuit measurements in the system, and the measurement error at various levels in sine wave within 5%.Figure 7 test waveformsreferences[1] TongShiBai. Analog electronic technology foundation. Beijing: higher education press, 2006 (4th edition)[2] WuDaZheng with linear system analysis. Signal. Beijing: higher education press, 2005 (4th edition)附录三：英文翻译波形合成电路的分析与设计薛莲 汪帆 郑锦发中南民族大学工商学院电信系，湖北 武汉 430065薛莲 (1981年11月——) 女，汉族，山东淄博，中南民族大学工商学院电信系教师，讲师，工学硕士。