CN103269253B - Passive intermodulation fault location detection circuit structure based on multiple order digital sweep frequency - Google Patents
Passive intermodulation fault location detection circuit structure based on multiple order digital sweep frequency Download PDFInfo
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Abstract
The invention relates to a passive intermodulation fault location detection circuit structure based on a multiple order digital sweep frequency, and belongs to the technical field of circuit structures. The passive intermodulation fault location detection circuit structure comprises a passive intermodulation measurement module and a multiple order digital sweep frequency fault location module. The passive intermodulation measurement module enables two signal sources to be combined into a high-power signal and then inputs the high-power signal to a measured system to obtain an intermodulation signal. The multiple order digital sweep frequency fault location module comprises an intermodulation reference signal producing unit, an M order intermodulation signal frequency choosing unit, a multiple order digital scanning generator unit and a fault location signal analysis unit. Therefore, rapid and accurate intermodulation testing can be achieved through adoption and using of a vector measurement mode, meanwhile a measurement order of passive intermodulation can be conveniently chosen, and fault location analysis of a multiple order passive intermodulation signal is achieved through calculation of signal transmission characteristics of the measured system. The passive intermodulation fault location detection circuit structure based on the multiple order digital sweep frequency is simple in structure, low in cost, and also wide in application range.
Description
Technical field
The present invention relates to circuit structure technical field, particularly passive cross modulation test circuit structure technical field, specifically refer to a kind of passive intermodulation fault location detection circuit structure based on multistage Digital Sweep.
Background technology
In mobile communication system, along with frequency band is more and more crowded, need the information content passed through day by day to increase in fixed-bandwidth, passive intermodulation becomes a key factor of restriction system capacity, is also the main cause causing present communication quality to decline.As in active device, two or more frequency mixes and just creates spurious signal in nonlinear device---passive intermodulation.When spuious inter-modulated signal drops in the frequency acceptance band of base station, the sensitivity of receiver will reduce, thus causes the minimizing of the reduction of speech quality or system carrier interference ratio (C/I) and the capacity of communication system.
Passive intermodulation is caused by many factors, comprising: Mechanical Contact is bad, the pollution in the magnetic conductor that comprises in radio-frequency channel and Conducted Radio Frequency face etc.Although accurately estimate that the passive intermodulation level of device is more difficult, characterizing device can be carried out by the data measured.Because the performance of passive intermodulation can change along with structural minor alteration, therefore manufacturer should carry out the inspection of 100% to the radio-frequency devices be applied in base station, to guarantee that the passive intermodulation of device maintains in acceptability limit all the time.
What good QoS requirement kept one can tolerate carries dry (C/I) ratio, therefore wishes that interference I is the smaller the better.In the ideal case, the end being always less than receiver is disturbed to make an uproar.Passive intermodulation distortion is the current mobile communication base station system problem that often can run into or trouble.Usually, base station antenna feeder system is when being injected into the carrier signal of two+43dBm, and passive intermodulation can not be greater than-110dBm, i.e.-153dBc.
Therefore, in order to the passive intermodulation distortion of test days feedback system, comparatively simple method injects the 20W signal of two fixed frequencies, and testing arrangement is received by Signal separator and high sensitivity, measures the performance number of the passive intermodulation distortion signal that antenna-feedback system produces.
The theory diagram of comparatively typical passive cross modulation test instrument as shown in Figure 1.Its basic functional principle is as follows: signal source 1 and signal source 2 are operated in the emission band of GSM respectively.When measuring, produce the frequency synthesis carrier signal with certain frequency difference, two-way carrier wave is respectively through after power amplifier, produce the signal being greater than+43dBm, after isolator, be input to two input ports of power combiner, by power combiner, high-power for two-way carrier signal synthesized a road signal.The high-power signal that power combiner exports is transferred to duplexer port, and output to test port by duplexer, the unit under test of test port or system, as the antenna feeder cable of base station, when being injected into the carrier signal of two+43dBm, owing to producing non-linear distortion, there will be the passive intermodulation interfering signals such as 3 rank, 5 rank, 7 rank.Inter-modulated signal enters into duplexer by measurement port again, and when the frequency of inter-modulated signal drops in the frequency acceptance band of communication system just, inter-modulated signal is just input to receiver by receiving filter.Usually, receiver needs very high receiving sensitivity, and a lot of passive cross modulation test instrument all adopts frequency spectrograph module, in order to improve receiving sensitivity, increase low-noise amplifier parts in the front end of frequency spectrograph module, make the sensitivity of receiver reach-135dBm, even higher.In order to measure the index of passive intermodulation distortion under 20W power rating, the signal power of test port necessarily can not be less than+43dBm, therefore the power of power amplifier output must have certain power headroom, thus the loss of isolator, combiner, duplexer and cable after can offsetting power amplifier, joint.
Passive intermodulation is the same with general intermodulation, all produced by two signal intermodulations, and intermodulation product comprises 3 rank, 5 rank, 7 rank and higher exponent number, and exponent number its energy higher is less.The frequency of intermodulation product can be calculated by following formula and obtain:
f
im＝mf
1+nf
2
In formula, m and n is integer, and its value can be zero, positive integer and negative integer, wherein | and m|+|n| is exactly the exponent number of passive intermodulation signal, shown in being specifically calculated as follows:
f
im3＝2×f
1±1×f
2；
f
im5＝3×f
1±2×f
2；
f
im7＝4×f
1±3×f
2；
f
im9＝5×f
1±4×f
2；
f
im11＝6×f
1±5×f
2；
The parasitic signal frequency of the non-linear generation of passive device is the linear combination of original signal frequency.In mobile communication system, the odd intermodulation product of lower-order has the greatest impact usually, because the maximum probability that they occur in base station receiving belt or uplink, and the intermodulation power of lower-order is also maximum, is just easy to produce signal disturbing in base station receiver.Usually, there is intermodulation index request base station to all parts in system, but due to the factor such as environment and product quality, the performance of intermodulation distortion can worsen, thus affects communication quality.Passive intermodulation analyzer can find and weigh the situation of device performance degradation effectively.
The passive intermodulation analyzer application of such scheme and the measurement of mobile communication base station can effectively measure and analyze the intermodulation distortion situation of antenna-feedback system, but as engineering maintenance instrument, still there are some problems in actual use in safeguarding:
1, owing to adopting frequency spectrograph as measuring receiver, approach vector during signal analysis, cannot be adopted to analyze measured signal;
2, the antenna-feedback system of mobile communication comprises many radio-frequency cables, adapter and antenna, and each parts exist the possibility that passive intermodulation index declines, and adopts such scheme one-shot measurement cannot differentiate the position of fault generation;
3, the location how realizing passive intermodulation fault is fast the problem to be solved in the present invention.
Summary of the invention
The object of the invention is to overcome above-mentioned shortcoming of the prior art, a kind of can utilization is provided to adopt the mode of vector measurement to realize accurate intermodulation testing fast, the measurement exponent number of passive intermodulation can be selected easily simultaneously, realize the fault locating analysis of multistage passive intermodulation signal, and structure is simple, with low cost, range of application is comparatively widely based on the passive intermodulation fault location detection circuit structure of multistage Digital Sweep.
In order to realize above-mentioned object, the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep of the present invention has following formation:
Passive intermodulation measurement module and multistage Digital Sweep fault location module should be comprised based on the passive intermodulation fault location detection circuit structure of multistage Digital Sweep.
Wherein, passive intermodulation measurement module comprises: two paths of signals source circuit, power combiner and duplexer.Two paths of signals source circuit comprises the first signal source and secondary signal source, in order to produce two-way independently signal in tested band system band respectively, also comprise power amplifier and isolator, the first signal source and secondary signal source all sequentially pass through the input that described power amplifier and isolator are connected to described power combiner; Power combiner by described two-way independently inband signal synthesize a road high-power signal; Described high-power signal is inputed to the described test port by examining system by duplexer, and the harmful inter-modulated signal returned by examining system is inputed to a measurement receiving path.
Described multistage Digital Sweep fault location module comprises: inter-modulated reference signal generation unit, M rank inter-modulated signal frequency selection unit, multistage digital scan generator unit and fault location signal analysis unit.
Wherein, the input of inter-modulated reference signal generation unit is connected to described two paths of signals source circuit, in order to produce composite signal, as inter-modulated reference signal according to the first described signal source and secondary signal source; M rank inter-modulated signal frequency selection unit, M is the exponent number needing the intermodulation distortion signals measured, it comprises the first frequency mixer, the second frequency mixer and He Ne laser local oscillator, described He Ne laser local oscillator is connected to the first described frequency mixer and the second mixer input respectively, the input of the first described frequency mixer also connects the measurement receiving path of described duplexer, and the input of the second described frequency mixer also connects described inter-modulated reference signal; Secondary signal source described in multistage digital scan generator unit connects and described He Ne laser local oscillator, in order to realize for the Synchronization Control between secondary signal source and He Ne laser local oscillator; The input of fault location signal analysis unit connects the first described frequency mixer and the output of the second frequency mixer respectively, in order to calculate the signal transmission characteristics by examining system according to the output signal of the first described frequency mixer and the second frequency mixer, and determine the trouble point that intermodulation produces.
Should based in the passive intermodulation fault location detection circuit structure of multistage Digital Sweep, described inter-modulated reference signal generation unit comprises two directional couplers and intermodulation produces circuit, the input of two described directional couplers connects the first described signal source and secondary signal source respectively, intermodulation described in the coupled end of two directional couplers connects produces the input of circuit, described intermodulation produce output that the output of circuit is described inter-modulated reference signal connect described in the input of the second frequency mixer.
Should based in the passive intermodulation fault location detection circuit structure of multistage Digital Sweep, it is that frequency mixer formula intermodulation produces circuit that described intermodulation produces circuit, this frequency mixer formula intermodulation produces circuit and comprises the first amplifier, second amplifier and three-mixer, the first described amplifier is connected the coupled end of two described directional couplers respectively with the input of the second amplifier, the first described amplifier is all connected the input of described three-mixer with the output of the second amplifier, the input of second frequency mixer described in output connection of the three-mixer be somebody's turn to do.
Should based in the passive intermodulation fault location detection circuit structure of multistage Digital Sweep, it is that amplifier intermodulation produces circuit that described intermodulation produces circuit, this amplifier intermodulation produces circuit and comprises the first amplifier, second amplifier and the 3rd amplifier, the first described amplifier is connected the coupled end of two described directional couplers respectively with the input of the second amplifier, the first described amplifier and the output of the second amplifier are all connected the input of the 3rd described amplifier, the input of second frequency mixer described in output connection of the 3rd amplifier be somebody's turn to do.
Should based in the passive intermodulation fault location detection circuit structure of multistage Digital Sweep, it is that PIN diode formula intermodulation produces circuit that described intermodulation produces circuit, this PIN diode formula intermodulation produces circuit and comprises the first amplifier, second amplifier and PIN diode, the first described amplifier is connected the coupled end of two described directional couplers respectively with the input of the second amplifier, node between the first described amplifier and the output of the second amplifier is connected to the input of the second described frequency mixer, the plus earth of described PIN diode, its negative electrode is connected between the input of described node and the second frequency mixer.
Should based in the passive intermodulation fault location detection circuit structure of multistage Digital Sweep, the measurement receiving path of described duplexer is provided with cavity body filter, the described harmful inter-modulated signal returned by examining system inputs to the input of described cavity body filter, the input of the first frequency mixer described in the output of this cavity body filter connects.
Should based in the passive intermodulation fault location detection circuit structure of multistage Digital Sweep, described multistage digital scan generator unit comprises: scan procedure pulse signal generator, scanning phase accumulator, segment phase accumulation amount register and multistage local frequency control register, the output of described scan procedure pulse signal generator is connected to described scanning phase accumulator respectively, segment phase accumulation amount register and multistage local frequency control register, the output of described segment phase accumulation amount register is also connected to described scanning phase accumulator, the output of described scanning phase accumulator is connected to described secondary signal source, and feeds back to the output of described scanning phase accumulator, He Ne laser local oscillator described in described multistage local frequency control register output connects.The local frequency f of described He Ne laser local oscillator
local oscillatordetermine according to following formula:
F
local oscillator=M × | f
signal source 1-f
signal source 2| ± f
signal source 2.
Should based in the passive intermodulation fault location detection circuit structure of multistage Digital Sweep, described fault location signal analysis unit comprises: two analog-digital converters, field programmable gate array and digital signal processors.
Two described analog-digital converters are connected to the first described frequency mixer and the output of the second frequency mixer; The input of field programmable gate array connects the output of two described analog-digital converters respectively, processes in order to the data signal exported analog-digital converter, and frequency domain measurement signal is converted to time-domain signal; Digital signal processor is connected to described field programmable gate array, in order to calculate the signal transmission characteristics by examining system according to described time-domain signal, and determines the trouble point that intermodulation produces.
Have employed the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep of this invention, it comprises passive intermodulation measurement module and multistage Digital Sweep fault location module; Passive intermodulation measurement module inputs to the test port by examining system after two signal sources are synthesized a road high-power signal, and obtains from the harmful inter-modulated signal returned by examining system; Described multistage Digital Sweep fault location module comprises inter-modulated reference signal generation unit, M rank inter-modulated signal frequency selection unit, multistage digital scan generator unit and fault location signal analysis unit; Thus the mode of employing vector measurement can be utilized to realize accurate intermodulation testing fast, the measurement exponent number M of passive intermodulation can be selected easily simultaneously, and by calculating the signal transmission characteristics by examining system, realize the fault locating analysis of multistage passive intermodulation signal, passive intermodulation fault location detection circuit structure based on multistage Digital Sweep of the present invention, its structure is simple, and with low cost, range of application is also comparatively extensive.
Accompanying drawing explanation
Fig. 1 is the theory diagram of typical passive cross modulation test instrument in prior art.
Fig. 2 is the structured flowchart of the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep of the present invention.
Fig. 3 is the electrical block diagram of the frequency mixer formula inter-modulated reference signal generation unit in the present invention.
Fig. 4 is the electrical block diagram of the amplifier inter-modulated reference signal generation unit in the present invention.
Fig. 5 is the electrical block diagram of the PIN diode formula inter-modulated reference signal generation unit in the present invention.
Fig. 6 is the electrical block diagram of the multistage digital scan generator unit in the present invention.
Fig. 7 is the M rank inter-modulated signal frequency selection unit electrical block diagram in the present invention.
Fig. 8 is the digitization frequencies sweep signal schematic diagram of the multistage digital scan generator unit in the present invention.
Detailed description of the invention
In order to more clearly understand technology contents of the present invention, describe in detail especially exemplified by following examples.
Referring to shown in Fig. 2, is the structured flowchart of the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep of the present invention.
In one embodiment, passive intermodulation measurement module and multistage Digital Sweep fault location module should be comprised based on the passive intermodulation fault location detection circuit structure of multistage Digital Sweep.
Wherein, passive intermodulation measurement module comprises two paths of signals source circuit, power combiner and duplexer.Two paths of signals source circuit comprises the first signal source and secondary signal source, in order to produce two-way independently signal in tested band system band respectively, also comprise power amplifier and isolator, the first signal source and secondary signal source all sequentially pass through the input that described power amplifier and isolator are connected to described power combiner; Power combiner by described two-way independently inband signal synthesize a road high-power signal; Described high-power signal is inputed to the described test port by examining system by duplexer, and the harmful inter-modulated signal returned by examining system is inputed to a measurement receiving path.This measurement receiving path is provided with the cavity body filter of high rejection ratio, and described harmful inter-modulated signal inputs to the input of described cavity body filter.
Described multistage Digital Sweep fault location module then comprises inter-modulated reference signal generation unit, M rank inter-modulated signal frequency selection unit, multistage digital scan generator unit and fault location signal analysis unit.
Wherein, the input of inter-modulated reference signal generation unit is connected to described two paths of signals source circuit, in order to produce the composite signal as inter-modulated reference signal according to the first described signal source and secondary signal source; M rank inter-modulated signal frequency selection unit as shown in Figure 7, M is the exponent number needing the intermodulation distortion signals measured, comprise the first frequency mixer, the second frequency mixer and He Ne laser local oscillator, described He Ne laser local oscillator is connected to the first described frequency mixer and the second mixer input respectively, the input of the first described frequency mixer also connects the output of described cavity body filter, and the input of the second described frequency mixer also connects described inter-modulated reference signal; Secondary signal source described in multistage digital scan generator unit connects and described He Ne laser local oscillator, in order to realize for the Synchronization Control between secondary signal source and He Ne laser local oscillator; The input of fault location signal analysis unit connects the first described frequency mixer and the output of the second frequency mixer respectively, in order to calculate the signal transmission characteristics by examining system according to the output signal of the first described frequency mixer and the second frequency mixer, and determine the trouble point that intermodulation produces.
In more preferably embodiment, described inter-modulated reference signal generation unit comprises two directional couplers and intermodulation produces circuit, the input of two described directional couplers connects the first described signal source and secondary signal source respectively, intermodulation described in the coupled end of two directional couplers connects produces the input of circuit, described intermodulation produce output that the output of circuit is described inter-modulated reference signal connect described in the input of the second frequency mixer.
In further preferred embodiment, it can be that frequency mixer formula intermodulation produces circuit, amplifier intermodulation produces circuit or PIN diode formula intermodulation produces circuit that described intermodulation produces circuit.
Frequency mixer formula intermodulation produces circuit, as shown in Figure 3, comprise the first amplifier, the second amplifier and three-mixer, the first described amplifier is connected the coupled end of two described directional couplers respectively with the input of the second amplifier, the first described amplifier is all connected the input of described three-mixer with the output of the second amplifier, the input of second frequency mixer described in output connection of the three-mixer be somebody's turn to do.
Amplifier intermodulation produces circuit, as shown in Figure 4, comprise the first amplifier, the second amplifier and the 3rd amplifier, the first described amplifier is connected the coupled end of two described directional couplers respectively with the input of the second amplifier, the first described amplifier and the output of the second amplifier are all connected the input of the 3rd described amplifier, the input of second frequency mixer described in output connection of the 3rd amplifier be somebody's turn to do.
PIN diode formula intermodulation produces circuit, as shown in Figure 5, comprise the first amplifier, the second amplifier and PIN diode, the first described amplifier is connected the coupled end of two described directional couplers respectively with the input of the second amplifier, node between the first described amplifier and the output of the second amplifier is connected to the input of the second described frequency mixer, the plus earth of described PIN diode, its negative electrode is connected between the input of described node and the second frequency mixer.
Further preferred embodiment in, described multistage digital scan generator unit, as shown in Figure 6, comprise scan procedure pulse signal generator, scanning phase accumulator, segment phase accumulation amount register and multistage local frequency control register, the output of described scan procedure pulse signal generator is connected to described scanning phase accumulator, segment phase accumulation amount register and multistage local frequency control register respectively, and the output of described segment phase accumulation amount register is also connected to described scanning phase accumulator; The output of described scanning phase accumulator is connected to described secondary signal source, and feeds back to the output of described scanning phase accumulator; He Ne laser local oscillator described in described multistage local frequency control register output connects.The local frequency f of described He Ne laser local oscillator
local oscillatordetermine according to following formula:
F
local oscillator=M × | f
signal source 1-f
signal source 2| ± f
signal source 2.
In preferred embodiment, described fault location signal analysis unit comprises: two analog-digital converters, field programmable gate array and digital signal processors.Two described analog-digital converters are connected to the first described frequency mixer and the output of the second frequency mixer; The input of field programmable gate array connects the output of two described analog-digital converters respectively, processes in order to the data signal exported analog-digital converter, and frequency domain measurement signal is converted to time-domain signal; Digital signal processor is connected to described field programmable gate array, in order to calculate the signal transmission characteristics by examining system according to described time-domain signal, and determines the trouble point that intermodulation produces.
In practical application of the present invention, basic passive intermodulation measurement module is substantially identical with passive intermodulation analyzer principle of the prior art, be all by two independently synthesized source produce two inband signalings, after power amplifier more than power amplification to+43dBm, after isolator, be input to two input ports of power combiner, by power combiner, high-power for two-way carrier signal synthesized a road signal.The high-power signal that power combiner exports is transferred to duplexer port, and outputs to test port by duplexer, and harmful inter-modulated signal that measured device produces is inputted by test port again, and enters measurement receiving path through duplexer and wave filter.Adding directional coupling circuits between signal source and power amplifier in the present invention, doing reference signal needed for fault location signal analysis for being coupled out two paths of signals source signal.
Emphasis of the present invention is multistage digital scan passive fault location measurement module circuit, mainly comprises multistage digital scan generator unit, inter-modulated reference signal generation unit, M rank inter-modulated signal frequency selection unit and fault location signal analysis unit.The object arranging multistage digital scan generator is that control signal source 2 realizes quick output signal frequency digital scanning in working band, its theory diagram as shown in Figure 6, it is made up of scan procedure pulse signal generator, scanning phase accumulator, segment phase accumulation amount register table, segmentation local frequency control register table, completes the Synchronization Control to signal source 2 and He Ne laser local oscillator respectively.Its method of work is: digitized sweep ramp circuit for generating reality does not exist, and it is substituted by a digital scan-synchronized circuit, the output frequency of working control signal source 2 and He Ne laser local oscillator.Now, signal source 2 has not been that continuous sweep exports, but with certain stepping-in amount Δ f stepping, this number of frequency steps is a fixed value, and the size of its value affects the accuracy of measurement of fault location, therefore needs coupling system design and signal analysis to determine.In single pass process, the frequency step scanning of signal source 2 stage ground, the frequency scanning of He Ne laser local oscillator and the output of signal source 2 are synchronously carried out, and frequency step is then M × Δ f, wherein M is the passive intermodulation product exponent number needing to measure, and frequency step scanning schematic diagram as shown in Figure 8.
In the present invention, inter-modulated reference signal generation unit is formed by several mode, respectively as shown in Fig. 3, Fig. 4, Fig. 5, its operation principle is that signal source 1 and signal source 2 are input to intermodulation generation circuit respectively through the signal that directional coupler coupled end exports, the core that intermodulation produces circuit can be the parts that frequency mixer, PIN diode, amplifier etc. can produce non-linear distortion, the coupled signal of signal source 1 and signal source 2 exports after non-linear distortion device has the composite signal enriching intermodulation product, and this signal is used for the reference signal of fault location signal analysis.
In the present invention, M rank inter-modulated signal frequency selection unit is made up of He Ne laser local oscillator and two-way mixting circuit, and theory diagram as shown in Figure 7.For GSM, working the mischief maximum to receiver is that inter-modulated signal enters receiver frequency band, therefore, what passive intermodulation measured major concern is that intermodulation product signals in frequency acceptance band is measured, also just because of this reason, the front end duplexer receiving path of intermodulation instrument is provided with the cavity body filter of a high rejection ratio, and the passive intermodulation product fallen in frequency acceptance band may be 3 rank, 5 rank, 7 rank, even more high-order.For this reason, in the present invention, the multistage local frequency controller synchronous with signal source 2 frequency sweep circuit controller is utilized to control the intermodulation distortion signals that M rank measured by receiver.The frequency of local oscillation signal is calculated by following formula and obtains, and wherein, M is the intermodulation distortion signals exponent number needing to measure.
F
local oscillator=M × | f
signal source 1-f
signal source 2| ± f
signal source 2.
In the present invention, fault location signal analysis unit is made up of FPGA and DSP, and as shown in Figure 2, inter-modulated signal measures intermediate frequency and inter-modulated reference intermediate frequency enters A/D converter unit respectively, sends into FPGA and do signal transacting after signal digitlization.In conjunction with intermodulation fault location circuit of the present invention, Measurement Algorithm adopts the signal processing method of inverse Fourier transform, frequency domain measurement signal is converted to time-domain signal, thus obtains the signal transmission characteristics of tested path, and calculates the trouble point of intermodulation generation.
Compared with prior art, the invention has the advantages that:
1, the present invention is owing to have employed inner intermodulation reference signal generation circuit, and adopts the mode of vector measurement, and make intermodulation testing speed faster, it is more accurate to measure;
2, multistage intermodulation selection circuit can make signal analysis select the measurement exponent number of passive intermodulation easily, applies closer to through engineering approaches;
3, the present invention is conceived by circuit and the combination of Measurement Algorithm, effectively achieves the fault locating analysis of multistage passive intermodulation signal;
4, the Digital Sweep control mode circuit changed according to inter-modulated signal exponent number is simple, substantially increases the measuring speed of fault location;
5, method frequency domain measurement signal being converted to time domain measurement signal by inverse Fourier transform effectively can observe multiple intermodulation trouble points of tested path, and certainty of measurement also improves thereupon greatly.
Have employed the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep of the present invention, it comprises passive intermodulation measurement module and multistage Digital Sweep fault location module; Passive intermodulation measurement module inputs to the test port by examining system after two signal sources are synthesized a road high-power signal, and obtains from the harmful inter-modulated signal returned by examining system; Described multistage Digital Sweep fault location module comprises inter-modulated reference signal generation unit, M rank inter-modulated signal frequency selection unit, multistage digital scan generator unit and fault location signal analysis unit; Thus the mode of employing vector measurement can be utilized to realize accurate intermodulation testing fast, the measurement exponent number M of passive intermodulation can be selected easily simultaneously, and by calculating the signal transmission characteristics by examining system, realize the fault locating analysis of multistage passive intermodulation signal, passive intermodulation fault location detection circuit structure based on multistage Digital Sweep of the present invention, its structure is simple, and with low cost, range of application is also comparatively extensive.
In this description, the present invention is described with reference to its specific embodiment.But, still can make various amendment and conversion obviously and not deviate from the spirit and scope of the present invention.Therefore, description and accompanying drawing are regarded in an illustrative, rather than a restrictive.
Claims (9)
1. based on a passive intermodulation fault location detection circuit structure for multistage Digital Sweep, comprise passive intermodulation measurement module, this passive intermodulation measurement module comprises:
Two paths of signals source circuit, comprises the first signal source and secondary signal source, in order to produce two-way independently signal in tested band system band respectively;
Power combiner, by described two-way independently inband signal synthesize a road high-power signal;
Duplexer, inputs to the described test port by examining system, and the harmful inter-modulated signal returned by examining system is inputed to a measurement receiving path by described high-power signal;
It is characterized in that, this circuit structure also comprises multistage Digital Sweep fault location module, and this multistage Digital Sweep fault location module comprises:
Inter-modulated reference signal generation unit, its input is connected to described two paths of signals source circuit, in order to produce composite signal, as inter-modulated reference signal according to the first described signal source and secondary signal source;
M rank inter-modulated signal frequency selection unit, M is the exponent number needing the intermodulation distortion signals measured, it comprises the first frequency mixer, the second frequency mixer and He Ne laser local oscillator, described He Ne laser local oscillator is connected to the first described frequency mixer and the second mixer input respectively, the input of the first described frequency mixer also connects the measurement receiving path of described duplexer, and the input of the second described frequency mixer also connects described inter-modulated reference signal;
Multistage digital scan generator unit, the secondary signal source described in connection and described He Ne laser local oscillator, in order to realize for the Synchronization Control between secondary signal source and He Ne laser local oscillator;
Fault location signal analysis unit, its input connects the first described frequency mixer and the output of the second frequency mixer respectively, in order to calculate the signal transmission characteristics by examining system according to the output signal of the first described frequency mixer and the second frequency mixer, and determine the trouble point that intermodulation produces;
The measurement receiving path of described duplexer is provided with cavity body filter, and the described harmful inter-modulated signal returned by examining system inputs to the input of described cavity body filter, the input of the first frequency mixer described in the output of this cavity body filter connects.
2. the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep according to claim 1, it is characterized in that, described inter-modulated reference signal generation unit comprises two directional couplers and intermodulation produces circuit, the input of two described directional couplers connects the first described signal source and secondary signal source respectively, the intermodulation described in coupled end connection of two directional couplers produces the input of circuit, the output of described intermodulation generation circuit is the output of described inter-modulated reference signal, the input of the second frequency mixer described in this inter-modulated reference signal output part connects.
3. the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep according to claim 2, it is characterized in that, it is that frequency mixer formula intermodulation produces circuit that described intermodulation produces circuit, this frequency mixer formula intermodulation produces circuit and comprises the first amplifier, second amplifier and three-mixer, the first described amplifier is connected the coupled end of two described directional couplers respectively with the input of the second amplifier, the first described amplifier is all connected the input of described three-mixer with the output of the second amplifier, the input of second frequency mixer described in output connection of the three-mixer be somebody's turn to do.
4. the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep according to claim 2, it is characterized in that, it is that amplifier intermodulation produces circuit that described intermodulation produces circuit, this amplifier intermodulation produces circuit and comprises the first amplifier, second amplifier and the 3rd amplifier, the first described amplifier is connected the coupled end of two described directional couplers respectively with the input of the second amplifier, the first described amplifier and the output of the second amplifier are all connected the input of the 3rd described amplifier, the input of second frequency mixer described in output connection of the 3rd amplifier be somebody's turn to do.
5. the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep according to claim 2, it is characterized in that, it is that PIN diode formula intermodulation produces circuit that described intermodulation produces circuit, this PIN diode formula intermodulation produces circuit and comprises the first amplifier, second amplifier and PIN diode, the first described amplifier is connected the coupled end of two described directional couplers respectively with the input of the second amplifier, node between the first described amplifier and the output of the second amplifier is connected to the input of the second described frequency mixer, the plus earth of described PIN diode, its negative electrode is connected between the input of described node and the second frequency mixer.
6. the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep according to claim 1, it is characterized in that, described multistage digital scan generator unit comprises: scan procedure pulse signal generator, scanning phase accumulator, segment phase accumulation amount register and multistage local frequency control register, the output of described scan procedure pulse signal generator is connected to described scanning phase accumulator respectively, segment phase accumulation amount register and multistage local frequency control register, the output of described segment phase accumulation amount register is also connected to described scanning phase accumulator, the output of described scanning phase accumulator is connected to described secondary signal source, and feeds back to the output of described scanning phase accumulator, He Ne laser local oscillator described in described multistage local frequency control register output connects.
7. the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep according to claim 6, is characterized in that, the local frequency f of described He Ne laser local oscillator
local oscillatordetermine according to following formula:
F
local oscillator=M × | f
signal source 1-f
signal source 2| ± f
signal source 2.
8. the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep according to claim 1, is characterized in that, described fault location signal analysis unit comprises:
Two analog-digital converters, are connected to the first described frequency mixer and the output of the second frequency mixer;
Field programmable gate array, its input connects the output of two described analog-digital converters respectively, processes in order to the data signal exported analog-digital converter, and frequency domain measurement signal is converted to time-domain signal;
Digital signal processor, is connected to described field programmable gate array, in order to calculate the signal transmission characteristics by examining system according to described time-domain signal, and determines the trouble point that intermodulation produces.
9. the passive intermodulation fault location detection circuit structure based on multistage Digital Sweep according to any one of claim 1 to 8, it is characterized in that, described two paths of signals source circuit all also comprises power amplifier and isolator, and the first described signal source and secondary signal source all sequentially pass through the input that described power amplifier and isolator are connected to described power combiner.
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| CN103605066A (en) * | 2013-08-30 | 2014-02-26 | 西安空间无线电技术研究所 | Passive intermodulation test system employing single power amplifier |
| CN103543427B (en) * | 2013-10-28 | 2016-05-25 | 中国电子科技集团公司第四十一研究所 | Passive cross modulation test system calibration steps and device based on intelligent search algorithm |
| WO2015180023A1 (en) * | 2014-05-26 | 2015-12-03 | 华为技术有限公司 | Signal processing apparatus and method |
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| CN105099586B (en) * | 2015-09-11 | 2017-11-21 | 中国电子科技集团公司第四十一研究所 | A kind of isolator passive cross modulation test device and method based on cavity filtering |
| CN106788784B (en) * | 2015-11-25 | 2020-07-10 | 西安交通大学 | Dynamic passive intermodulation reference signal generator |
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| CN113783632B (en) * | 2021-09-14 | 2024-04-05 | 福建星海通信科技有限公司 | Device and method for quantitatively measuring nonlinearity of passive device |
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| CN114509757B (en) * | 2022-01-11 | 2023-07-18 | 电子科技大学 | Screening and screening method for secondary induced passive intermodulation sources in cavity |
| CN116112005B (en) * | 2022-12-30 | 2024-02-13 | 成都电科星拓科技有限公司 | Delay measurement method, equipment and storage medium of DTC delay unit |
| CN116016397B (en) * | 2023-03-28 | 2023-05-30 | 湖南毂梁微电子有限公司 | Method and circuit for quickly searching message transmission buffer area |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102156139A (en) * | 2011-04-08 | 2011-08-17 | 浙江大学 | Method and system for measuring passive intermodulation generation point of microwave device by using electromagnetic wave phase |
| KR20120065127A (en) * | 2010-12-10 | 2012-06-20 | 에이스웨이브텍(주) | Poor pim point estimation device using for phase |
| CN103002493A (en) * | 2012-12-11 | 2013-03-27 | 华为技术有限公司 | Passive intermodulation detection method and device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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-
2013
- 2013-04-24 CN CN201310145704.3A patent/CN103269253B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20120065127A (en) * | 2010-12-10 | 2012-06-20 | 에이스웨이브텍(주) | Poor pim point estimation device using for phase |
| CN102156139A (en) * | 2011-04-08 | 2011-08-17 | 浙江大学 | Method and system for measuring passive intermodulation generation point of microwave device by using electromagnetic wave phase |
| CN103002493A (en) * | 2012-12-11 | 2013-03-27 | 华为技术有限公司 | Passive intermodulation detection method and device |
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