CN105978533A - Composite filter - Google Patents
Composite filter Download PDFInfo
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- CN105978533A CN105978533A CN201610438049.4A CN201610438049A CN105978533A CN 105978533 A CN105978533 A CN 105978533A CN 201610438049 A CN201610438049 A CN 201610438049A CN 105978533 A CN105978533 A CN 105978533A
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- filter
- band
- frequency
- band elimination
- cut
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H17/00—Networks using digital techniques
- H03H17/02—Frequency selective networks
- H03H17/0283—Filters characterised by the filter structure
- H03H17/0286—Combinations of filter structures
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H17/00—Networks using digital techniques
- H03H17/02—Frequency selective networks
- H03H17/0211—Frequency selective networks using specific transformation algorithms, e.g. WALSH functions, Fermat transforms, Mersenne transforms, polynomial transforms, Hilbert transforms
- H03H17/0213—Frequency domain filters using Fourier transforms
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- Mathematical Physics (AREA)
- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- General Physics & Mathematics (AREA)
- Computing Systems (AREA)
- Algebra (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Networks Using Active Elements (AREA)
- Analogue/Digital Conversion (AREA)
Abstract
The invention discloses a composite filter, which comprises an on-off controller, an analog filter and a digital filter, wherein the analog filter comprises a first-order analog filter and a second-order analog filter; the on-off controller is connected to a band-pass filter 1; after respectively connected to first, second and third band elimination filters, the band-pass filter I is connected to an input of a frequency mixer; an output of the frequency mixer is divided into two ways, one way is connected to the second-order analog filter and the other way is connected to a band-pass filter II or a fourth band elimination filter through a switch selector I; the second-order analog filter, the band-pass filter II and the fourth band elimination filter are all connected to the frequency mixer and are connected to an A/D converter and a digital simulator through a band-pass filter III. Through the analog filter, primary filtration is carried out on the signal and the further filtering processing is carried out on the signal by the A/D converter through the digital filter, so that the signal can be converted according to the scene signal environment, the filtering effect is good and the reliability is high.
Description
Technical field
The present invention relates to a kind of composite filter, belong to signal of communication processing technology field.
Background technology
Wave filter is exactly frequency selector, is that one can make useful signal pass through and simultaneously to unwanted frequency
Signal carries out suppressing the electronic installation of (or decay).Commonly use it in engineering and do signal processing, data transmission
With suppression interference etc., its principle selects the frequency content of needs the most exactly, and unwanted frequency is become
Dividing and remove, wave filter is divided into again analog filter and digital filter.Simulation in Control System of Microcomputer inputs
In signal, generally individually contain various noise and interference, they from measured signal source itself, sensor, outer
Boundary's interference etc..In order to accurately measure and control, it is necessary to eliminate the noise in measured signal and interference.
Digital filter without phase distortion, there is no additional noise, and frequency characteristic good stability.But number
The power consumption of word wave filter is typically big than analog filter, need more complicated Digital Signal Processing knowledge, reality
Execute relative difficulty, time-consuming, use and sampling is repeated several times, periodic noise is difficult to improve numerical accuracy and adapts to
Frequency range relatively small, the generally filtering of low frequency, intermediate frequency range, and speed is the slowest.And mould
Intending filter filtering speed very fast, system is simple, and the wide frequency range of adaptation, frequency can cover whole
Physical frequencies scope, but there is phase distortion, amplitude-frequency characteristic and phase-frequency characteristic are difficult to take into account, and have
Additional noise.Therefore, how to have two kinds of respective advantages of wave filter concurrently, preferably apply in conjunction with cost control
In complicated signal environment, it it is letter problem to be solved.
Summary of the invention
In order to solve the weak point existing for above-mentioned technology, the invention provides a kind of composite filter.
In order to solve above technical problem, the technical solution used in the present invention is: a kind of composite filter, it
Including switch controller, analog filter and digital filter；Analog filter includes single order analog filter
With second order analog filter；Single order analog filter include band filter the I, first band elimination filter,
Two band elimination filters and the 3rd band elimination filter；Switch controller is connected with the input of band filter 1, band
The output of bandpass filter I respectively with input, the input of the second band elimination filter and of the first band elimination filter
The input of three band elimination filters is connected；First band elimination filter, the second band elimination filter and the resistance filter of the 3rd band
The output of ripple device is all connected with the input of frequency mixer；
The output of frequency mixer sends two branch roads, and one is connected with the input of second order analog filter, another
I is selected to be connected with the input of band filter II or the input of the 4th band elimination filter by switch；Two
The output of rank analog filter, the output of band filter II, the 4th band elimination filter output all and frequency
The input of blender is connected；The output of frequency mixer is connected with the input of band filter III, and band is logical
The output of wave filter III is connected with digital simulator by A/D converter.
Digital simulator is divided into the Wideband Digital Filter being arranged in parallel and narrow-band digital simulator；A/D changes
Device selects II to be connected with the input of Wideband Digital Filter or narrow-band digital simulator by switch.
Second order analog filter is divided into bivalent high-pass filter and the second-order low-pass filter of setting parallel with one another；
The cut-off frequency of bivalent high-pass filter is less than the cut-off frequency of second-order low-pass filter.
Band filter II and band filter III are ceramic filter.The inductance arranged in analog filter
And between electric capacity, it is provided with division board.
The upper cut-off frequency of band filter I is more than the first band elimination filter, the second band elimination filter and the
The upper cut-off frequency of three band elimination filters, the lower-cut-off frequency of band filter I is more than the first band resistance filter
Ripple device, the second band elimination filter and the lower-cut-off frequency of the 3rd band elimination filter.
The upper cut-off frequency of the first band elimination filter, lower-cut-off frequency are respectively smaller than the second band elimination filter
Upper cut-off frequency, lower-cut-off frequency with the 3rd band elimination filter.
The upper cut-off frequency of the second band elimination filter is more than the upper cut-off frequency of the 3rd band elimination filter；The
The lower-cut-off frequency of two band elimination filters is less than the lower-cut-off frequency of the 3rd band elimination filter.
The composite filter that the present invention provides, by being used in combination of analog filter and digital filter, first
First pass through analog filter and analogue signal is carried out primary filter and screening, then turned by A/D converter
Do further Filtering Processing through digital filter again after changing digital signal into, be selected to according to existing by switch
The complexity of field signal carries out flexible transformation, and good wave filtering effect, reliability are high, and cost and power consumption obtain
Arrive effective control.
Accompanying drawing explanation
Fig. 1 is that the structure of the present invention connects block diagram.
Detailed description of the invention
The present invention is further detailed explanation with detailed description of the invention below in conjunction with the accompanying drawings.
As it is shown in figure 1, the present invention includes switch controller, analog filter and digital filter；Simulation filter
Ripple device includes single order analog filter and second order analog filter；Single order analog filter includes band filter
I, the first band elimination filter, the second band elimination filter and the 3rd band elimination filter；Switch controller is logical with band
The input of wave filter 1 connects, the output of band filter 1 respectively with the input of the first band elimination filter, second
The input of band elimination filter is connected with the input of the 3rd band elimination filter；First band elimination filter, the second band
The output of resistance wave filter and the 3rd band elimination filter is all connected with the input of frequency mixer；
The output of frequency mixer sends two branch roads, and one is connected with the input of second order analog filter, another
I is selected to be connected with the input of band filter II or the input of the 4th band elimination filter by switch；Two
The output of rank analog filter, the output of band filter II, the 4th band elimination filter output all and frequency
The input of blender is connected；The output of frequency mixer is connected with the input of band filter III, and band is logical
The output of wave filter III is connected with digital simulator by A/D converter.
Digital simulator is divided into the Wideband Digital Filter being arranged in parallel and narrow-band digital simulator；A/D changes
Device selects II to be connected with the input of Wideband Digital Filter or narrow-band digital simulator, to adapt to by switch
Different filtering index requests.
Second order analog filter is divided into the bivalent high-pass filter and two of setting parallel with one another by the present invention further
Rank low pass filter；The cut-off frequency of bivalent high-pass filter is less than the cut-off frequency of second-order low-pass filter.
Therefore both combine meeting more step refining filter range frequency, will be located in the filtering letter between both cut-off frequencies
Number retained.
Band filter II and band filter III are ceramic filter.It mainly utilizes ceramic material piezoelectricity
Effect realizes the conversion of the signal of telecommunication → mechanical vibration → signal of telecommunication, thus replaces the LC filter in part electronic circuit
Wave circuit so that it is performance is more stable.It is provided with isolation between the inductance and the electric capacity that arrange in analog filter
Plate.So can be prevented effectively from interference, reduce coupling, it is to avoid loss.
The present invention is when specifically arranging, and the upper cut-off frequency of band filter I is more than the first bandreject filtering
Device, the second band elimination filter and the upper cut-off frequency of the 3rd band elimination filter, the lower limit of band filter I
Cut-off frequency is more than the first band elimination filter, the second band elimination filter and the low cutoff of the 3rd band elimination filter
Frequency.Signal first passes through band filter I entrance, it is achieved the first step of primary filter, arranges concrete
Time in order to reduce the loss of useful signal, the upper and lower cut-off frequency of band filter I generally expands selection
Scope, the signal after therefore filtering is entering the first band elimination filter, the second band elimination filter and the resistance of the 3rd band
Can realize during wave filter filtering step by step, retain useful signal further, that is collected by band filter I is useless
Signal filters further, and the setting of concrete cut-off frequency can be set according to Site Design, but need to meet one
Individual design criteria, it may be assumed that the upper cut-off frequency of the first band elimination filter, lower-cut-off frequency are respectively smaller than
Two band elimination filters and the upper cut-off frequency of the 3rd band elimination filter, lower-cut-off frequency.Second band resistance filter
The upper cut-off frequency of ripple device is more than the upper cut-off frequency of the 3rd band elimination filter；Second band elimination filter
Lower-cut-off frequency is less than the lower-cut-off frequency of the 3rd band elimination filter.
Through the above signal filtered again through frequency mixer hybrid frequency, form new signal frequency, then by two
Level analog filter or switch select I with the inputting or the 4th band elimination filter defeated of band filter II
Enter to be connected；Finally by frequency mixer, various frequency signals are mixed, but do not produce new
Signal frequency, is so to carry out concrete signal frequency and filter and divide to remain into band filter III.This
Sample by the signal frequency of band filter III after export with digital simulator through A/D converter, numeral filter
Ripple device designs the transmission function of wave filter in frequency domain, is multiplied with the Fourier transformation of primary signal, more instead
Fourier transformation is gone back.
Above-mentioned embodiment is not limitation of the present invention, and the present invention is also not limited to the example above, this
Change that those skilled in the art are made in the range of technical scheme, retrofit, add or
Replace, also belong to protection scope of the present invention.
Claims (8)
1. a composite filter, it is characterised in that: it includes switch controller, analog filter sum
Word wave filter；Described analog filter includes single order analog filter and second order analog filter；Described single order
Analog filter includes band filter the I, first band elimination filter, the second band elimination filter and the resistance of the 3rd band
Wave filter；Described switch controller is connected with the input of band filter 1, and the output of band filter 1 is respectively
Input, the input of the second band elimination filter and the input phase of the 3rd band elimination filter with the first band elimination filter
Connect；The output of described first band elimination filter, the second band elimination filter and the 3rd band elimination filter is all with mixed
Frequently the input of device is connected；
The output of described frequency mixer sends two branch roads, and one is connected with the input of second order analog filter, separately
Article one, select I to be connected with the input of band filter II or the input of the 4th band elimination filter by switch
Connect；The output of described second order analog filter, the output of band filter II, the 4th band elimination filter defeated
Go out and be all connected with the input of frequency mixer；The output of described frequency mixer is defeated with band filter III
Entering to be connected, the output of described band filter III is connected with digital simulator by A/D converter.
Composite filter the most according to claim 1, it is characterised in that: described digital simulator is divided into
The Wideband Digital Filter being arranged in parallel and narrow-band digital simulator；Described A/D converter is selected by switch
II is connected with the input of Wideband Digital Filter or narrow-band digital simulator.
Composite filter the most according to claim 1, it is characterised in that: described second order analog filter
It is divided into bivalent high-pass filter and the second-order low-pass filter of setting parallel with one another；Described bivalent high-pass filter
Cut-off frequency less than the cut-off frequency of second-order low-pass filter.
Composite filter the most according to claim 1, it is characterised in that: described band filter II He
Band filter III is ceramic filter.
Composite filter the most according to claim 1, it is characterised in that: set in described analog filter
It is provided with division board between inductance and the electric capacity put.
Composite filter the most according to claim 1, it is characterised in that: described band filter I
Upper cut-off frequency is more than the first band elimination filter, the second band elimination filter and the upper limit of the 3rd band elimination filter
Cut-off frequency, the lower-cut-off frequency of described band filter I is more than the first band elimination filter, the second band resistance
Wave filter and the lower-cut-off frequency of the 3rd band elimination filter.
Composite filter the most according to claim 6, it is characterised in that: described first band elimination filter
Upper cut-off frequency, lower-cut-off frequency be respectively smaller than the second band elimination filter and the 3rd band elimination filter
Upper cut-off frequency, lower-cut-off frequency.
Composite filter the most according to claim 7, it is characterised in that: described second band elimination filter
Upper cut-off frequency more than the upper cut-off frequency of the 3rd band elimination filter；The lower limit of the second band elimination filter
Cut-off frequency is less than the lower-cut-off frequency of the 3rd band elimination filter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610438049.4A CN105978533A (en) | 2016-06-18 | 2016-06-18 | Composite filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610438049.4A CN105978533A (en) | 2016-06-18 | 2016-06-18 | Composite filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105978533A true CN105978533A (en) | 2016-09-28 |
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ID=57021948
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610438049.4A Pending CN105978533A (en) | 2016-06-18 | 2016-06-18 | Composite filter |
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| Country | Link |
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| CN (1) | CN105978533A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114157964A (en) * | 2021-12-15 | 2022-03-08 | 科大讯飞股份有限公司 | Audio circuit and apparatus |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1166089A (en) * | 1996-05-15 | 1997-11-26 | 德国汤姆逊-布朗特公司 | Amplifier circuit with filters for digital and analogue signals |
| US20050094754A1 (en) * | 2003-10-31 | 2005-05-05 | Sanyo Electric Co., Ltd. | Data regeneration apparatus |
| US20070271056A1 (en) * | 2006-05-22 | 2007-11-22 | Mettler-Toledo Ag | Method for processing the output signal of a measurement transducer, and force-measuring device |
| CN202309641U (en) * | 2011-11-02 | 2012-07-04 | 广东圣大电子有限公司 | Integrated miniwatt frequency hopping electrically tunable filter |
| CN205215213U (en) * | 2015-11-30 | 2016-05-11 | 常熟理工学院 | Novel electrocardio guardianship device |
| CN205829594U (en) * | 2016-06-18 | 2016-12-21 | 南通尚青医疗科技有限公司 | A kind of composite filter |
-
2016
- 2016-06-18 CN CN201610438049.4A patent/CN105978533A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1166089A (en) * | 1996-05-15 | 1997-11-26 | 德国汤姆逊-布朗特公司 | Amplifier circuit with filters for digital and analogue signals |
| US20050094754A1 (en) * | 2003-10-31 | 2005-05-05 | Sanyo Electric Co., Ltd. | Data regeneration apparatus |
| US20070271056A1 (en) * | 2006-05-22 | 2007-11-22 | Mettler-Toledo Ag | Method for processing the output signal of a measurement transducer, and force-measuring device |
| CN202309641U (en) * | 2011-11-02 | 2012-07-04 | 广东圣大电子有限公司 | Integrated miniwatt frequency hopping electrically tunable filter |
| CN205215213U (en) * | 2015-11-30 | 2016-05-11 | 常熟理工学院 | Novel electrocardio guardianship device |
| CN205829594U (en) * | 2016-06-18 | 2016-12-21 | 南通尚青医疗科技有限公司 | A kind of composite filter |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114157964A (en) * | 2021-12-15 | 2022-03-08 | 科大讯飞股份有限公司 | Audio circuit and apparatus |
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Application publication date: 20160928 |