Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Instantaneous frequency detection method and system for frequency sweeping source

A technology of instantaneous frequency and detection method, which is applied in the microwave field, can solve the problems of high price, poor performance, and high cost, and achieve the effect of large instantaneous bandwidth, low sampling rate, and easy realization

Inactive Publication Date: 2015-02-04
BEIJING UNIV OF POSTS & TELECOMM
View PDF2 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Such a high instantaneous frequency has exceeded the highest bandwidth of the current ADC, so it must be equipped with an expensive high-frequency mixer and a local oscillator microwave source, which is very expensive
Although the envelope detection circuit can detect the failure of the frequency sweep source output in the entire frequency band, it cannot measure the instantaneous output frequency, so complete calibration cannot be achieved
[0006] In general, the current methods cannot realize the simultaneous detection of instantaneous output frequency and faults of ultra-wideband frequency sweep sources at low cost
Moreover, the performance of the above methods is not good enough when the real-time requirements of the measurement are relatively high.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Instantaneous frequency detection method and system for frequency sweeping source
  • Instantaneous frequency detection method and system for frequency sweeping source
  • Instantaneous frequency detection method and system for frequency sweeping source

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0057] Example 1: Detect the instantaneous frequency and fault conditions output by the frequency sweep source (Agilent E8257D) in the range of 500MHz~2.5GHz. Such as figure 1 As shown, the used N-bit PRBS symbol rate f PRBS =6.35GHz, the code length N=127 bits, and the repetition frequency corresponding to the PRBS code is f repetition =6.35GHz / 127=50MHz. The bandwidth of low-pass filter LPF-1 and LPF-2 is B=25MHz, and the real-time sampling module is a dual-channel real-time sampling oscilloscope, and the sampling rate of each channel is 50MS / s. The selection of parameters in the example needs to ensure the adopted N-bit PRBS symbol rate f PRBS Greater than the frequency sweep range B of the frequency sweep signal to be tested s , N-bit PRBS code signal repetition frequency f repetition (f repetition =f PRBS / N) is equal to the ADC sampling rate f ADC , channel 1 and channel 2 low-pass filter bandwidth B LPF for f ADC / 2. The above requirements can be expressed in...

example 2

[0062]Example 2: Detect the instantaneous frequency and interruption faults output by the frequency sweep source (Agilent E8257D) in the range of 2.5GHz~5GHz. The selected experimental parameters are the same as in Example 1. The energy spectrum after the short-time Fourier transform of the sampled data through channel 1 of the real-time sampling module and figure 1 The middle and lower arms input reference signals of different frequencies, and follow the same steps in Example 1 to obtain the instantaneous frequency output by the frequency sweep source and the interruption fault situation as follows: Figure 5 as shown in Figure 5 It can be seen that when the frequency sweep source is working in a different frequency band, a frequency sweep period is 44ms, and the interruption time takes up 21ms. The instantaneous frequency and interrupt fault condition of the output at any moment of the scan can be known.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses an instantaneous frequency detection method for a sweep frequency source, and relates to the technical field of microwaves. The method comprises the following steps of: S1: modulating a swept-frequency signal output from the sweep frequency source to an optical field, and dividing the modulated signal into two signals; S2: modulating a first signal by adopting a periodic coding sequence to obtain a beat frequency signal of the first signal and the periodic coding sequence, performing low-pass filtering on the beat frequency signal, simultaneously modulating a second signal by adopting a reference microwave signal to obtain a beat frequency signal of the second signal and the reference microwave signal, and performing the low-pass filtering on the beat frequency signal; and S3: synchronously sampling the first beat frequency signal and the second beat frequency signal which are subjected to the low-pass filtering, and calculating the instantaneous frequency of the sweep frequency source according to the sampling signals. The invention also discloses an instantaneous frequency detection system for the sweep frequency source, and the instantaneous frequency detection system can detect an instantaneous frequency of an ultra wide band (UWB) frequency sweeping source; and moreover, the cost is low.

Description

technical field [0001] The invention relates to the field of microwave technology, in particular to a method and system for detecting the instantaneous frequency of a sweeping source. Background technique [0002] Ideally, a swept source is a microwave source whose output RF frequency varies linearly with time. Sweep frequency sources are widely used in various occasions, such as: as a signal generator in a frequency-modulated continuous wave radar system; as a frequency reference local oscillator in a spectrum analyzer; as an excitation source in excitation input / response measurement, etc. In each frequency sweep cycle, the output frequency of the frequency sweep source varies with time basically constant. However, due to the non-ideality of the circuit of the frequency sweeping source itself, its output frequency changes nonlinearly with time, and there are scanning interruption faults caused by circuit frequency band switching. That is, the frequency of the sweeping sig...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): G01R23/02
Inventor 闫励戴一堂谢小军王瑞鑫高宇洋徐坤林金桐
Owner BEIJING UNIV OF POSTS & TELECOMM
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com