Controllable gain general frequency converter for multiplication digital/analog converter

Abstract

This invention provides a controllable gain transducer based on a multiplication D / A converter including multiplication D / A converter2, base frequency and gain code generating circuit 6, frequency-selective circuit 3, D / A converter 4 and signal processor 5, in which, a signal received by a receiver is changed to signal 1 with a carrier frequency and envolope information after pre-amplification and filter circuit, which is input from the voltage reference end of 2 and through frequyency-selective circuit 3 to get a necessary base frequency signal to be input into D / A converter 4 to be collected and processed by signal processor 5 to be input into the base frequency and gain code generation circuit, the output of which is input into the multiplication D / A comverter2, which combines traditional mutual independent frequency conversion and gain control circuit modules by the multiplication function of a multiplication D / A converter to increase flexibility and adaptive ability of the system.

Description

(1) Technical field [0001] The invention relates to a frequency conversion and gain control circuit, in particular to a frequency conversion and gain control circuit widely used in the fields of radar, sonar, communication and medical treatment. (2) Background technology [0002] In the fields of radar, sonar, communication and medical treatment, most systems need to convert the received signal with a higher carrier frequency into a signal with a lower carrier frequency through down conversion, and then perform sampling and subsequent processing , so the frequency conversion circuit is an indispensable part of many systems in the above fields. In addition, due to the different influences of the environment, channel and target characteristics, the strength of the received signal of the system varies greatly. In order to make the system have the same adaptability to different signals, the receiver must have certain amplification and filtering functions. Certain gain control c...

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Problems solved by technology

In addition, due to the different influences of the environment, channel and target characteristics, the strength of the received signal of the system varies greatly. In order to make the system have the same adaptability to different signals, the receiver must have certain amplification and filtering functions. Certain gain control capability

[0003] The traditional frequency conversion and gain control are usually two independent circuit modules, that is, the signal is amplified or reduced to a certain range by the gain control circuit and then the frequency conversion operation is performed by the frequency conversion circuit. Therefore, the hardware scale of the system is generally large, and the parameters are determined. Generally, the frequency conversion circuit can only achieve one fundamental frequency, which reduces the flexibility and applicability of the system

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