CN106961841B - Very low frequency signal converter - Google Patents
Very low frequency signal converterInfo
- Publication number
- CN106961841B CN106961841B CN200910026176.3A CN200910026176A CN106961841B CN 106961841 B CN106961841 B CN 106961841B CN 200910026176 A CN200910026176 A CN 200910026176A CN 106961841 B CN106961841 B CN 106961841B
- Authority
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- China
- Prior art keywords
- signal
- dds
- frequency
- low frequency
- frequency signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- 230000015572 biosynthetic process Effects 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims abstract description 5
- 238000003786 synthesis reaction Methods 0.000 claims abstract description 5
- 230000002194 synthesizing Effects 0.000 claims abstract description 5
- 238000004891 communication Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000000051 modifying Effects 0.000 description 2
- 230000000875 corresponding Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000002452 interceptive Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000001429 stepping Effects 0.000 description 1
Abstract
Very low frequency signal converter, the very low frequency signal for short-wave receiver is converted, including two direct digital synthesis technique chip DDS integrated circuits, four bandpass filters and a mixting circuit；Reception signal from antenna is input to four bandpass filters of parallel connection, the output of bandpass filter connects mixting circuit, DDS output also connects mixting circuit, and the very low frequency of antenna is received signal and is multiplied with DDS local oscillation signal by mixting circuit, exports 10.7MHz high frequency signal；Four bandpass filters, filter the various interference from reception antenna and front end input equipment；The FREQUENCY CONTROL of DDS integrated circuits and bandpass filter terminates the frequency tuning output end of the short-wave receiver.
Description
First, technical field：
The technical field of the invention is applied to naval vessels communication short-wave reception system.Especially VLF very low frequencys
Signal converter.
2nd, background technology：
The receiving frequency of common short-wave receiver is 100kHz~30MHz, but the common shortwave of marine vessel is comprehensive
Frequency reception requirement of the communication system to short-wave receiver is 10kHz~30MHz, it is impossible to fully meet system requirements, must
The signal of 10~100kHz scopes must be handled, existing common receiver is handled the signal of this frequency range,
The technical requirements of communication system are reached with this.Simultaneously because the low-frequency interference signal of marine vessel is complex, also require
AF panel processing is carried out to 10~100kHz signal.
3rd, the content of the invention
The present invention seeks to：A kind of very low frequency VLF signal converters are proposed, are transformed especially by simple device, energy
Enough receive the all-wave of the non-complete pair signals of all-wave receiver, i.e., can receive 10~100kHz VLF signals,
Meet the design requirement of marine vessel shortwave integrated communications system.
The present invention technical solution be：VLF signal converters, using external VLF signal converters, are adopted
Constituted with 2 direct digital synthesis technique chip DDS integrated circuits, 4 bandpass filters and a mixer；
Reception signal from antenna is input to 4 bandpass filters of parallel connection, and the output of bandpass filter connects mixting circuit,
DDS output also connects mixting circuit, and the very low frequency of antenna is received signal and DDS local oscillation signal phase by mixting circuit
Multiply, export 10.7MHz high frequency signal.4 bandpass filters, filter and are set from reception antenna and front end input
Standby various interference, this four wave bands are divided into：10~20kHz of first band, 20~35kHz of second band, the 3rd
35~60kHz of wave band, the 4th 60~100kHz of wave band.The effect of DDS parts is 10.6~10.69MHz of generation
Local oscillation signal；Mixting circuit effect is that very low frequency signal is multiplied with local oscillation signal, output 10.7MHz medium-high frequency letter
Number.The FREQUENCY CONTROL code of DDS integrated circuits and bandpass filter is from the short-wave receiver for needing to transform.
Above-mentioned frequency mixer is the main building block of upconverter module, it by from DDS signal (10.6~
10.69MHz) and the signal multiplication from antenna, it is fixed the 10.7MHz of frequency signal.The letter that DDS is sent out
Number, it is to be controlled by the control signal of receiver, its frequency values subtract the frequency for the signal to be received for 10.7MHz
Rate.Two multiplications by frequency mixer, it is possible to which the signal for obtaining 10.7MHz is sent to receiver and goes processing.
The beneficial effect of invention：The present invention is applied in certain carrier-borne shortwave integrated communications system, meets systems technology
It is required that, have passed through various experiments.Naval vessels are in active service.Possess many prominent using direct digital synthesis technique chip
The advantage gone out：Phase keeps the continuous, frequency of ultra-wide when high frequency resolution, high-frequency switch speed, frequency error factor
Scope, the generation that various modulating waves and random waveform can be realized and it is easily achieved design of total digitalization etc..It can facilitate
Linear frequency modulation, pure-tone pulse and step frequency signal are rapidly produced, its working frequency is up to hundreds of MHz, polydispersity
Energy index is good.
4th, illustrate
Fig. 1 composition frame charts of the present invention；
The fundamental diagram of Fig. 2 upconverter；
Fig. 3 band pass filter circuits.
5th, embodiment
1st, the Specifeca tion speeification of the embodiment of the present invention
Working frequency：10~100kHz；
Mode of operation：It is digital, 1Hz steppings；
Input and output impedance：50 ohm；
Output frequency：Fixed 10.7MHz；
Noise coefficient：No more than 6dB.
2nd, the circuit course of work
10~100kHz whole VLF wave band, is divided into four wave bands, and 4 bandpass filters are respectively adopted,
The various interference from reception antenna and front end input equipment are filtered, this four wave bands are divided into：First band 10~
20kHz, 20~35kHz of second band, the 3rd 35~60kHz of wave band, the 4th 60~100kHz of wave band.This four ripples
The selection control of section is controlled by the control signal from receiver.When reception system requirement reception VLF frequency ranges,
Control signal is sent into frequency converter by receiver by 8 parallel ports (or serial ports), connects VLF signal converter circuits
Enter in radio frequency path, while making reception state of the receiver in 10.7MHz.VLF signal converters will pass through band logical
The local oscillation signal that the radiofrequency signal and DDS of wave filter are produced is mixed, and generates the medium-high frequency of 10.7MHz fixed frequencies
Signal.Receiver is received to 10.7MHz fixed frequency signals, demodulated again.
It is made up of in VLF converters two parts, RF parts and DDS parts.The main processing in RF parts comes from day
The signal of line, and filtering interfering, and the judgement whether signal is bypassed and decayed.DDS parts act as production
Raw 10.6~10.69MHz local oscillation signal.
There is a frequency mixer in upconverter module, it is by the signal (10.6~10.69MHz) from DDS and from day
The signal multiplication of line, is fixed the 10.7MHz of frequency signal.The signal that DDS is sent out, is the control by receiver
Signal control processed, its frequency values subtract the frequency for the signal to be received for 10.7MHz.Two signals are through overmulling
The multiplication of frequency device, it is possible to obtain 10.7MHz signal be sent to receiver go processing, as shown in Figure 2.DDS circuit
Standard module is used with frequency mixer.
3.1st, RF circuits
Radio frequency part is main by protection circuit part, bandpass filter part, frequency multiplication part, bypass attenuation portions
And other interlock circuits composition.
Protection circuit.What it was mainly made up of a discharge tube and detection slsllwwde circuit.
Bandpass filter.4 wave bands are divided into 10~100kHz, by the difference of receives frequency set by receiver,
Judge wave filter of the selection using which wave band, reach the purpose for more preferably removing noise jamming.The circuit of bandpass filter
Figure such as Fig. 3.This bandpass filter is one or three rank bandpass filters, and the bandpass filter of four wave bands uses identical structure,
It is simply different in the selection of device.
Mixting circuit.The main function of mixting circuit is by the useful signal from antenna and the mixing of the signal from DDS
10.7MHz receiver input signal is obtained, receiver is sent to and is used as reception.Mixting circuit is using an integrated circuit
MX1-SRA6。
3.2nd, DDS parts
Direct digital synthesis technique chip DDS parts are mainly made up of DDS chips and corresponding logic control circuit.
The DDS chips used are AD7008, and the frequency range of generation is 10.6~10.69MHz, and system clock source is
36MHz.DDS control signal is produced from receiver or when using innernal CPU by the logic circuit of oneself.Mould
There are two DDS chips in block, one of DDS chips are used as the signal for producing 10.6~10.69MHz.Other one
DDS chips are used as receiver test.When receiver needs test, a signal can be produced by it, as
Signal source, to observe the service condition of receiver.Theory diagram is shown in accompanying drawing.
Claims (2)
1. very low frequency signal converter, the very low frequency signal for short-wave receiver is converted, the very low frequency signal refers to
10~100kHz VLF signals, it is characterized in that including two direct digital synthesis technique chip DDS integrated circuits,
Four bandpass filters and a mixting circuit；Reception signal from antenna is input to four bandpass filters of parallel connection,
The output of bandpass filter connects mixting circuit, and DDS output also connects mixting circuit, and mixting circuit is by the very low of antenna
Frequency receives signal and is multiplied with DDS local oscillation signal, exports 10.7MHz high frequency signal；Four bandpass filters,
The various interference from reception antenna and front end input equipment are filtered, this four wave bands are divided into：First band 10~
20kHz, 20~35kHz of second band, the 3rd 35~60kHz of wave band, the 4th 60~100kHz of wave band；DDS collection
It is the DDS integrated circuits of generation 10.6~10.69MHz local oscillation signals into circuit；Mixting circuit receives antenna very
Low frequency signal and 10.6~10.69MHz local oscillation signal are multiplied, and export 10.7MHz high frequency signal；DDS collection
FREQUENCY CONTROL into circuit and bandpass filter terminates the frequency tuning output end of the short-wave receiver.
2. very low frequency signal converter according to claim 1, it is characterized in that the signal of DDS outputs, be by
The control signal control of short-wave receiver, its frequency values subtract the frequency for the signal to be received for 10.7MHz.
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106961841B true CN106961841B (en) | 2013-05-08 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108281792A (en) * | 2017-12-28 | 2018-07-13 | 中国电子科技集团公司第二十研究所 | A kind of very low frequency near-field emissions system |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108281792A (en) * | 2017-12-28 | 2018-07-13 | 中国电子科技集团公司第二十研究所 | A kind of very low frequency near-field emissions system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR03 | Grant of secret patent right | ||
| DC01 | Secret patent status has been lifted | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130508 Termination date: 20210402 |