Digital type phase jitter modulation amplitude automatic gain control circuit

Abstract

The invention belongs to the digital communication field, used in the digital phase jitter modulation range automatic gain control circuit of the digital communication tester, wherein the circuit comprises a microprocessor, a resistance attenuation network, a high speed A / D converter and a programmable chip including a maximum search circuit, a feedback computing circuit and a controller. The resistance attenuation network controls the phase jitter signals on the modulator in the same range under the control of the microprocessor, then outputs the digital signals corresponding to the jitter range of the modulation signal through the high speed A / D converter sampling, conversion, and measures the peak value of the jitter modulation signal by the maximum search circuit, wherein once the signal is read by the microprocessor, then is transmitted to the feedback computing circuit, and computes the set amplitude control parameter signal required by the set jitter modulation range. The invention has the advantages of simple circuit form, good consistency of the products, strong antijamming capability, high reliability, no non-linear, no compensation, easy realization of the range expansion and the control precision.

Description

Technical field [0001] The invention belongs to the field of digital communication and is used for a digital phase jitter modulation amplitude automatic gain control circuit in a digital communication tester. technical background [0002] Phase jitter modulation is one of the important functions of digital communication testers. It is usually composed of three parts: a modulation signal generation circuit, a clock phase modulation circuit, and a modulation amplitude gain control circuit. Due to the nonlinearity of the circuit, the gain control of the modulation amplitude is the decisive factor to maintain the accuracy and stability of the jitter modulation amplitude under different modulation frequencies and different working environments. At present, the known modulation amplitude gain control adopts analog phase jitter modulation amplitude gain control circuit, which has inherent disadvantages such as complex circuit, serious environmental impact on the circuit itself, an...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to overcome the shortcomings of the existing analog phase jitter modulation amplitude gain control circuit, and provide a digital phase jitter modulation amplitude automatic gain control circuit with simple circuit, easy realization of amplitude control accuracy, and easy range expansion

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