A Difference Frequency Converter Based on Logarithmic Amplifier

Abstract

The invention discloses a difference frequency indicator based on a log amplifier. The difference frequency indicator comprises a first resistor and a second resistor. A first signal source is input into one end of the first resistor, the other end of the first resistor is respectively connected with the positive pole of a first diode and the negative pole of a second diode, and the negative pole of the first diode and the positive pole of the second diode are connected with an output end of an operational amplifier at the same time to output difference frequency signal voltage. The first diode is in parallel connection with a capacitor. A second signal source is input into one end of the second resistor, and the other end of the second resistor is respectively connected with the positive pole of the first diode, the negative pole of the second diode and the negative polarity input end of the operational amplifier. The positive polarity input end of the operational amplifier is grounded. The difference frequency indicator based on the log amplifier is easy to operate and simple in structure, stable and high-precision difference frequency signals can be conveniently acquired, integration can be easily achieved, circuit cost is reduced, and various needs in practical application are met.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a frequency difference device based on a logarithmic amplifier. Background technique [0002] The frequency difference device is a nonlinear device, and the frequency of the output signal is equal to the difference between the frequencies of the two input signals. The frequency difference devices in the prior art are usually diode frequency difference devices, balanced frequency difference devices and transistor frequency difference devices, all of which are composed of inductors and transformers. [0003] In the process of realizing the present invention, the inventor finds that at least the following disadvantages and deficiencies exist in the prior art: [0004] 1) The mutual influence between the circuits of the above frequency difference device is serious, and the combined frequency interference is also relatively large, resulting in the instability of the obtained diff...

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Problems solved by technology

[0004] 1) The mutual influence between the circuits of the above frequency difference device is serious, and the combined frequency interference is also relatively large, resulting in the instability of the obtained difference frequency signal;

[0005] 2) The above-mentioned difference frequency converter is greatly affected by the discreteness of component parameters, and the dynamic range of the signal that can be processed is small;

[0006] 3) The obtained difference frequency signal is an attenuated signal with low sensitivity, which is difficult to meet various needs in practical applications

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