Sweep generator based on digital zero intermediate frequency

Abstract

The invention belongs to the field of instrument measurement and particularly relates to a sweep generator based on digital zero intermediate frequency. In the sweep generator, a sweep frequency source has three paths of outputs; the first path is connected with one end of a to-be-tested network; the second path is respectively connected with two analog multipliers; the third path is only connected with the second analog multiplier; the other end of the to-be-tested network is connected with the first analog multiplier; output ports of the two analog multipliers are respectively connected with input ports of two analog filters; output ports of the two analog filters are respectively connected with input ports of two paths of digital analog converters; output ports of the two paths of digital analog converters are connected with different ports of a digital signal processing module; the digital signal processing module is used for realizing the digital zero intermediate frequency orthogonalization, phase difference and amplitude ratio calculation for the output signals of the two paths of digital analog converters and outputting the result. According to the sweep generator, the design difficulty of the simulating sweep frequency source is reduced, the influence caused by the quantization error of the digital device is reduced, the software calculation difficulty is reduced and the measurement precision is improved.

Description

technical field [0001] The invention belongs to the field of instrument measurement, in particular to a frequency sweeper based on digital zero-intermediate frequency. Background technique [0002] Frequency characteristic tester, also known as frequency sweeper, is used to test the amplitude-frequency characteristics and phase-frequency characteristics of the network, and occupies an important position in the field of electronic measurement. Its core frequency characteristic measurement principle is still the focus of research in the industry. At present, high-end frequency characteristic testers are expensive, bulky, complicated to operate, and difficult to maintain. Therefore, high-performance, low-cost frequency characteristic testers are more likely to be widely accepted by the market. [0003] With the development of modern electronic measurement technology, various types of frequency characteristic measurement principles have emerged as the times require. From the e...

AI Technical Summary

Problems solved by technology

The problem with this method is that it is difficult to guarantee the orthogonality of the local oscillator generated by the analog circuit, and the bias voltage and noise brought by the active device will bring a large error to the filtered DC signal, which increases the complexity of signal processing. difficulty

Images