Universal high-precision electronic control balance compensation device

Abstract

The invention discloses a universal high-precision electronic control balance compensation device. The system comprises a main control module and a basic electric control equalization module, the basic electric control equalization module comprises a digital stepping attenuator with the model of PE4314; and a peripheral circuit of the digital step attenuator, The device is characterized in that the device is characterized by comprising a rack; the slope frequency selection module is used for adjusting the medium-high frequency; High-frequency fine tuning module, the slope frequency selection module comprises a numerical control adjustable capacitor; the high-frequency fine tuning module comprises a variable capacitance diode; wherein the control end of the numerical control adjustable capacitor is electrically connected with the main control module and is used for controlling the numerical control adjustable capacitor to output a variable capacitor so as to improve the waveform bulge,and the variable capacitance diode is also electrically connected with the main control module and is used for controlling the variable capacitance diode to output a variable capacitor so as to improve the waveform drop of a high frequency point. The universal high-precision electronic control equalization compensation device can obtain good signal waveform flatness at each slope.

Description

technical field [0001] The invention relates to the technical field of cable TV network, in particular to a universal high-precision electronically controlled equalization compensation device. Background technique [0002] In a cable television network (abbreviated as CATV hereinafter), CATV signals will cause loss during cable / optical fiber transmission. Among them, the attenuation characteristic of the cable / optical fiber increases with the increase of the frequency, on the other hand, the attenuation of the signal increases with the increase of the distance of the cable / fiber. Therefore, for transmission cables / optical fibers with different distances, the transmission signal will have different attenuation slopes, which requires equalization circuits with different slope values ​​to equalize the attenuation of the signal and balance the in-band curve so that the signal can be transmitted stably and high-quality over long distances . [0003] In the downlink amplifier an...

AI Technical Summary

Problems solved by technology

Compared with the first scheme, the second scheme has lower design cost, but both schemes need to be equipped with basic equalization modules or in-line attenuators with different slope values, which is not only inconvenient to operate, but also As the number of nodes used increases, the demand for basic equalization modules or in-line attenuators will also increase greatly, which will cost a lot of money in terms of cost and maintenance

[0004] However, the following technical problems still exist in the existing general-purpose electronically controlled equalization module: because the fifth capacitor C5 and the tenth capacitor C10 in the peripheral circuit of the digital step attenuator U1 are all selected and fixed according to the frequency response characteristics under a certain slope Parameters, while the slope of the general-purpose electronically controlled equalization module varies greatly, usually between 0dB and 22dB. In this way, when the slope of the digital control attenuator U1 changes, due to the change of impedance and the frequency response characteristics of the circuit itself, resulting in The flatness of the signal waveform of the digitally controlled attenuator U1 at other different slopes will have a large change, such as figure 2 As shown, generally, the waveforms with different slopes will rise with the increase of the slope value, and the high-frequency points will drop slightly with the increase of the slope value, which will affect the characteristics and accuracy of the transmitted signal, and the flatness of the signal waveform It refers to the degree to which the gain is close to a linear relationship with the frequency within the frequency range, and the frequency range is generally 54MHZ-1218MHZ

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