CN202353599U - Adjacent-channel interference restraining circuit for microwave transceivers - Google Patents
Adjacent-channel interference restraining circuit for microwave transceivers Download PDFInfo
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- CN202353599U CN202353599U CN2011205108160U CN201120510816U CN202353599U CN 202353599 U CN202353599 U CN 202353599U CN 2011205108160 U CN2011205108160 U CN 2011205108160U CN 201120510816 U CN201120510816 U CN 201120510816U CN 202353599 U CN202353599 U CN 202353599U
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Abstract
The utility model discloses an adjacent-channel interference restraining circuit for microwave transceivers, which comprises a cavity filter, a receiving high-frequency processing unit and a receiving medium frequency processing unit, wherein the cavity filter is used for filtering interference signals in microwave signals; the receiving high-frequency processing unit is used for converting radio-frequency signals into medium-high frequency signals; the receiving medium frequency processing unit performs a secondary down-conversion on the signals; and the cavity filter, the receiving high-frequency processing unit and the receiving medium frequency processing unit are connected sequentially. The adjacent-channel interference restraining circuit for microwave transceivers can be achieved through intermediate frequency amplifiers which can reduce pre-amp gains of medium frequency mixers, increase post-amp gains of the medium frequency mixers, or choose proper gains and linear index, the circuit can also be regulated by means of increasing general PI attenuators and the like so as to reduce input of the medium frequency mixers under the condition that the overall gain is constant, eliminate or improve non-linear signals output by the medium frequency mixers and achieve an effect of restraining adjacent-channel interferences.
Description
Technical field
The utility model relates to the technical field of microwave communication, and particularly a kind of microwave transmitting and receiving equipment suppresses the adjacent circuit that disturbs frequently.
Background technology
Along with the fast development of mobile communication business, digital microwave systems are more and more in the netting index amount, and frequency resource is more and more nervous, and the adjacent interference problem frequently of digital microwave systems more and more highlights.And suppress adjacent the interference frequently in wireless or the microwave system is an industry difficult problem always; In the prior art, solution mainly is to adopt the filter of various high characteristics, but because these filters self also exist some defectives; Big such as Insertion Loss in the band; Group delay is too big, can't be applied in the present hicap the common suitable high-order modulating of hicap (such as 256QAM).In addition, also there is the expensive problem of cost.
In addition, even adopted above scheme, generally still can't reach desirable effect.Etsi standard (the ETSI EN 302217-2-2V1.4.1 (2010-07) that present industry generally adopts; Wherein 4H D.4STM-014MHz require the adjacent C/I frequently of rollback 1dB≤-6dB); Wireless or microwave system does not reach standard-required greatly in fact; Even those satisfy standard-required, also be just up to standard.
The utility model content
The shortcoming that the purpose of the utility model is to overcome prior art provides a kind of microwave transmitting and receiving equipment to suppress the adjacent circuit that disturbs frequently with not enough.
In order to achieve the above object, the utility model adopts following technical scheme:
A kind of microwave transmitting and receiving equipment of the utility model suppresses the adjacent circuit that disturbs frequently; The cavity body filter that is used for filtering microwave signal interference signal that comprises, be used for radiofrequency signal is converted into the reception high frequency processing unit of medium-high frequency signal and signal is carried out the reception IF processing unit of secondary down-conversion said cavity body filter, reception high frequency processing unit and receive IF processing unit and be linked in sequence.
Preferably; Said reception IF processing unit comprises the AGC control loop; The electrically controlled attenuator that is linked in sequence, first intermediate frequency amplifier, second intermediate frequency amplifier, reception intermediate-frequency filter group and AGC control chip; Said AGC control loop one end connects the AGC control chip, and the other end connects electrically controlled attenuator.
Preferably, said intermediate-frequency filter group comprises ceramic filter, intermediate frequency mixer and a plurality of intermediate-frequency filter.
Preferably, the input power of said first amplifier is-65dBm～5dBm.
Preferably, said first Amplifier Gain is no more than 15dB, and said second Amplifier Gain is more than or equal to 20dB.
The utility model has following advantage and effect with respect to prior art:
1, the utility model need not changed original design, and is compatible with general design, implements convenient and simple.
2, the utility model need not increase intermediate-frequency filter, need not change the more intermediate-frequency filter of the outer suppression characteristic of high-band yet, provides cost savings.
3, the utility model can improve the influence of the non-linear composition of interference signal generation in band to main signal, reduces the inhibition neighbour and frequently disturbs bottleneck, and effect is obvious, than the about 10dB of etsi standard index optimization.
Description of drawings
Fig. 1 is that the utility model microwave transmitting and receiving equipment receives the link sketch map;
Fig. 2 is the circuit structure diagram that the utility model receives IF processing unit;
Fig. 3 is that the utility model suppresses the adjacent linear bottleneck sketch map that disturbs frequently.
Embodiment
Below in conjunction with embodiment and accompanying drawing the utility model is described in further detail, but the execution mode of the utility model is not limited thereto.
Embodiment
Digital microwave systems are made up of digital modems (digital microwave systems indoor unit), microwave transmitting and receiving equipment (digital microwave systems outdoor unit) and microwave antenna.Microwave transmitting and receiving equipment, data feedback channel are realized emission medium-frequency is transformed to the emission radio frequency, and amplifying signal is given microwave antenna simultaneously; Down going channel is realized transforming to the reception intermediate frequency from the received RF that microwave antenna is brought, simultaneously amplifying signal.
As shown in Figure 1, the adjacent circuit that disturbs frequently of microwave transmitting and receiving equipment inhibition is made up of cavity body filter (duplexer), reception high frequency processing unit and reception IF processing unit, and the key that suppresses adjacent interference frequently is in the reception IF processing unit.Radio frequency rf signal receives system's radio frequency receiving port through antenna, suppresses other signal beyond certain frequency band range through duplexer, because of system's receive frequency adjustable in certain limit, so duplexer only has certain adjacent frequency inhibition ability to the border frequency.Said reception high frequency processing unit carries out the low noise amplification to receiving the RF signal, and carries out down-conversion one time, converts radiofrequency signal into the medium-high frequency signal.Said reception IF processing unit centering high-frequency signal carries out the secondary down-conversion; Reach IF interface requirement frequency; And have an automatic gain control function, when radiofrequency signal when certain limit fluctuates, can realize that intermediate frequency power output weighing apparatus is fixed; Have the signal selection function in addition, the interference signal outer to main signal suppresses.
As shown in Figure 2, said reception IF processing unit is made up of ceramic filter, electrically controlled attenuator, first intermediate frequency amplifier, second intermediate frequency amplifier, intermediate frequency mixer, at least one intermediate-frequency filter and AGC control chip and control circuit thereof.The present embodiment first intermediate frequency amplifier PA1 and the second intermediate frequency amplifier PA2 type selecting should be followed following requirement: under the normal condition, the PA1 input power range is about :-65dBm～5dBm, intermediate frequency mixer device IP3 performance index are 20dB.When main signal during near threshold of senstitivity; Add+30dB monkey chatter signal; The first intermediate frequency amplifier PA1 input power is about-15dBm; As require Δ >=40dBc, and then first intermediate frequency amplifier PA1 gain maximum can not surpass 15dB, and first intermediate frequency amplifier PA1 gain is 13.5dB in this circuit.This circuit receives the link overall gain and requires minimum to reach 80dB, because the first intermediate frequency amplifier PA1 device maximum gain limit, the gain minimum that the second intermediate frequency amplifier PA2 device distributes need reach 20dB, and device PA2 gain is 23dB in this circuit.
Owing to need take into account broadband services, the bandwidth of ceramic filter is bigger, and is very little to suppressing adjacent interference performance effect frequently, even do not have fully.Generally speaking, suppress the adjacent outer inhibition ability of band of leaning on intermediate-frequency filter basically fully of disturbing frequently., after to a certain degree, no matter how to improve intermediate-frequency filter, the number that perhaps increases intermediate-frequency filter all can't further promote and suppress adjacent interference capability frequently.Reason is that interference signal (band signal) is big with respect to carrier signal, even big a lot.In this case; Receiving IF processing unit neutral line bottleneck makes in the non-linear composition incoming carrier signal band of interference signal; And amplitude is bigger, and intermediate-frequency filter can suppress to be with exterior portions, but has no inhibition for part in the band; No matter how to improve intermediate-frequency filter thus, the number that perhaps increases intermediate-frequency filter all can't further promote and suppress adjacent interference capability frequently.
As shown in Figure 3, the utility model reduces the influence of the non-linear composition of interference signal to carrier signal through eliminating or improving the linear bottleneck that receives IF processing unit.Generally speaking, intermediate frequency mixer is linear bottleneck, and concrete grammar is the gain that reduces the intermediate frequency mixer prime, the gain of level behind the increase intermediate frequency mixer.This can realize through the intermediate frequency amplifier of selecting suitable gain and linear index, also can regulate through increasing means such as common PI attenuator.Make under the constant situation of overall gain, reduce the intermediate frequency mixer input, thereby eliminate or improve the nonlinear properties of intermediate frequency mixer output, reach and suppress adjacent effects of jamming frequently.
The foregoing description is the utility model preferred implementation; But the execution mode of the utility model is not restricted to the described embodiments; Other any do not deviate from change, the modification done under spirit and the principle of the utility model, substitutes, combination, simplify; All should be the substitute mode of equivalence, be included within the protection range of the utility model.
Claims (5)
1. a microwave transmitting and receiving equipment suppresses the adjacent circuit that disturbs frequently; It is characterized in that; The cavity body filter that is used for filtering microwave signal interference signal that comprises, be used for radiofrequency signal is converted into the reception high frequency processing unit of medium-high frequency signal and signal is carried out the reception IF processing unit of secondary down-conversion said cavity body filter, reception high frequency processing unit and receive IF processing unit and be linked in sequence.
2. microwave transmitting and receiving equipment according to claim 1 suppresses the adjacent circuit that disturbs frequently; It is characterized in that; Said reception IF processing unit comprises the AGC control loop; The electrically controlled attenuator that is linked in sequence, first intermediate frequency amplifier, second intermediate frequency amplifier, reception intermediate-frequency filter group and AGC control chip, said AGC control loop one end connects the AGC control chip, and the other end connects electrically controlled attenuator.
3. microwave transmitting and receiving equipment according to claim 2 suppresses the adjacent circuit that disturbs frequently, it is characterized in that said reception intermediate-frequency filter group comprises ceramic filter, intermediate frequency mixer and a plurality of intermediate-frequency filter.
4. microwave transmitting and receiving equipment according to claim 2 suppresses the adjacent circuit that disturbs frequently, it is characterized in that the input power of said first amplifier is-65dBm～5dBm.
5. microwave transmitting and receiving equipment according to claim 2 suppresses the adjacent circuit that disturbs frequently, it is characterized in that said first Amplifier Gain is no more than 15dB, and said second Amplifier Gain is more than or equal to 20dB.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205108160U CN202353599U (en) | 2011-12-08 | 2011-12-08 | Adjacent-channel interference restraining circuit for microwave transceivers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205108160U CN202353599U (en) | 2011-12-08 | 2011-12-08 | Adjacent-channel interference restraining circuit for microwave transceivers |
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| Publication Number | Publication Date |
|---|---|
| CN202353599U true CN202353599U (en) | 2012-07-25 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2011205108160U Expired - Fee Related CN202353599U (en) | 2011-12-08 | 2011-12-08 | Adjacent-channel interference restraining circuit for microwave transceivers |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113541705A (en) * | 2020-04-21 | 2021-10-22 | 国基电子（上海）有限公司 | Adjacent frequency interference resisting device and method |
-
2011
- 2011-12-08 CN CN2011205108160U patent/CN202353599U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113541705A (en) * | 2020-04-21 | 2021-10-22 | 国基电子（上海）有限公司 | Adjacent frequency interference resisting device and method |
| CN113541705B (en) * | 2020-04-21 | 2022-10-04 | 富联国基(上海)电子有限公司 | Device and method for resisting adjacent frequency interference |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120725 Termination date: 20131208 |