Front low-pass filter designed with insertion attenuation method
A low-pass filter and filter technology, which is applied to waveguide devices, electrical components, circuits, etc., can solve problems such as unspecified harmonic retention, poor stopband characteristics, and large performance defects.
Inactive Publication Date: 2014-12-24
浙江隆沅消防科技有限公司
View PDF1 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
[0003] In the arc fault detection device (AFDD), the pre-filter is designed by the image parameter method, which mainly includes two design methods of fixed K type and M deduction type. Large performance defects, such as poor phase-frequency characteristics after filtering, inaccurate cut-off frequency, poor stopband characteristics, and the inability to retain specified harmonics, especially when the frequency bands of the useful signal and the interference signal overlap, it is necessary to follow the random signal Some internal statistical distribution rules can best extract useful signals, and this method cannot accurately design a pre-filter that meets the requirements
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 moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0024] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings, so that those skilled in the art can better understand the present invention.
[0025] see figure 1 , filter design block diagram. It mainly includes finding a realizable rational function H a (s) To approach the frequency characteristic curve of the filter to be designed, use the circuit structure and parameter values of the two-port network to realize H a (s). According to the performance index of the provided filter (σ p , σ s , Ω p , Ω s etc.), find out the frequency characteristic response that satisfies the conditions (not necessarily achievable with a circuit), and draw its graph, and then seek different function prototypes to approximate it according to the requirements of the actual situation, and obtain a realizable rational function H a (s); then determine the circuit structure and parameter values of the two-port network acco...
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
Login to View More Abstract
The invention relates to a front low-pass filter designed with an insertion attenuation method. The method mainly comprises the steps that a realizable rational function Ha(s) is searched for to approach the frequency characteristic curve of the filter to be designed, and the Ha(s) is realized through a circuit structure and parameter values of a two-port network. First, an ideal frequency characteristic curve which cannot always be realized through a circuit is obtained according to the performance indexes (rho p, rho s, omega p, omega s and the like) of the filter, different function prototypes are selected for approaching the ideal frequency characteristic curve according to the requirement of actual conditions (for example, a Butterworth type is selected for meeting the high requirement for a phase characteristic), and thus the realizable rational function Ha(s) is obtained; then, the circuit structure and the parameter values of the two-port network are determined according to the Ha(s), and finally an actual analog circuit is obtained.
Description
technical field [0001] The invention belongs to the technical field of analog filters, and in particular relates to a pre-low-pass filter designed by an insertion attenuation method. Background technique [0002] Most acquisition devices require a signal with limited bandwidth in the frequency domain (determined by the sampling theorem) for the signal to be processed. However, since there are many interference signals in the power system, it is necessary to filter the input signal at this time (the limit is the highest frequency), that is, the original signal is converted into a band-limited signal through a pre-filter before processing; on the other hand, due to the backwardness of the chip processing speed and hardware equipment, the improvement of the sampling frequency is limited; so in order to ensure the frequency domain of the sampled signal If there is no aliasing phenomenon, the original signal must be band-limited filtered (pre-filter) before A / D sampling. At this...
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
Login to View More Patent Type & Authority Applications(China)
IPC IPC(8): H01P1/203
Inventor 周格伊刘兵黄振乐刘凯霞
Owner 浙江隆沅消防科技有限公司