Summary of the invention
The present invention has realized a kind of antenna and transmission line tester that can real-time automatic calibrating, and the user does not in use need to carry out any manual calibration operation, can be tested at any time.
According to an aspect of the present invention, realized a kind of antenna and transmission line tester that can real-time automatic calibrating, described antenna and transmission line tester comprise: signal synthesizing module (1), power splitter (2), directional coupler (3), width Phase Receiver machine module (5), FPGA Digital IF Processing module (6), cpu controller (7), FLASH storer (9), temperature sensor (10); Test port (4) is connected with directional coupler (3); Communication interface (8) is connected with cpu controller (7).
According to an aspect of the present invention, signal synthesizing module (1) is comprised of exciting signal source (11) and local oscillation signal source (12).
According to an aspect of the present invention, described temperature sensor (10) carries out temperature detection in real time, and the error coefficient file prestores in described FLASH storer (9).
According to an aspect of the present invention, width Phase Receiver machine module comprises two frequency mixer and two moduluses (A/D) converter, the first frequency mixer carries out mixing for the road to power splitter (2) output as the signal of reference signal and a road signal of local oscillation signal source (12) output, and mixer output signal outputs to the first input end mouth of FPGA Digital IF Processing module after the R passage is exaggerated filtering and analog to digital conversion; The second frequency mixer carries out mixing for the road to directional coupler (3) output as the signal of measured piece reflected signal and another road signal of local oscillation signal source (12) output, and mixer output signal outputs to the second input port of FPGA Digital IF Processing module after A channel is exaggerated filtering and analog to digital conversion.
According to an aspect of the present invention, FPGA Digital IF Processing module (6) is carried out I/Q decomposition and filtering to digital medium-frequency signal, extracts amplitude information and the phase information of tested network, and sends to cpu controller (7).
According to another aspect of the present invention, realized a kind of antenna and transmission line method of testing that can real-time automatic calibrating, when tester is started shooting, at first the error coefficient file has been read to internal memory; Carry out the two-dimensional interpolation calculating of error coefficient according to current frequency values and current temperature value, obtain suitable error coefficient item; It is characterized in that, the error coefficient solution procedure comprises:
A, judge the scope of current frequency f:
The deterministic process of current frequency f scope judges the f value is between which two Frequency point of error coefficient file:
Step is 1.: establish a counting variable i=0;
Step is 2.: judge whether freqStart+i * freqStep≤f≤freqStart+ (i+1) * freqStep sets up;
Step is 3.: if 2. step is false, make i=i+1, repeating step 2.~3.; If 2. step is set up, carry out step 4.;
Step is 4.: if 2. step is set up, in the error coefficient file, between i and i+1 point, the frequency values that i is ordered is that freqStart+i * freqStep is designated as f1 to the frequency f value; The frequency values that i+1 is ordered is that freqStart+ (i+1) * freqStep is designated as f2, completes judgement.
Wherein, freqStart is in the error coefficient file prestored in instrument, the initial frequency that error coefficient is corresponding;
FreqStep is in the error coefficient file prestored in instrument, the step frequency that error coefficient is corresponding;
N is in the error coefficient file prestored in instrument, the Frequency point number that error coefficient is corresponding.
In above deterministic process, the i variable can be increased to N-2 by 0, frequency f f1=freqStart+ (N-2) * freqStep between latter two Frequency point in the error coefficient file when i=N-2, f2=freqStart+ (N-1) * freqStep
If freqStart+i * freqStep≤f≤freqStart+ (i+1) * freqStep 0≤i≤N-2
Make f1=freqStart+i * freqStep;
f2=freqStart+(i+1)×freqStep;
Current frequency f is positioned at [f
1, f
2] scope, frequency interpolation is calculated will use f
1point and f
2the point data;
The scope of B, judgement Current Temperatures C:
Read three temperature values from data file, make Current Temperatures in these three temperature values between certain two, and they are sorted, if ranking results is C1≤C2≤C3, if c≤C2, the data that in the usage data file, temperature C1 and temperature C2 are corresponding are carried out interpolation calculation, if c>C2, the data that in the usage data file, temperature C2 and temperature C3 are corresponding are carried out interpolation calculation, establish Current Temperatures c≤C2 herein;
C, according to frequency, carry out interpolation:
The directional error coefficient data at temperature C1, frequency f place draws by the line segment interpolation:
Temperature C1, source, frequency f place coupling, skin tracking error coefficient are:
The error coefficient at temperature C2, frequency f place is:
D, obtain the directional error coefficient at Current Temperatures c place by the line segment interpolation:
The source coupling at temperature c place, skin tracking error coefficient are:
According to another aspect of the present invention, as temperature c, when frequency f changes, the automatic repeating step A of tester, B, C obtain new error coefficient item.
Tester of the present invention in use without any need for calibration operation, save time, improve testing efficiency; The automatic calibration algorithm of this tester can carry out error coefficient calculating in real time according to the variation of temperature and set of frequency.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, rather than whole embodiment.Embodiment based in the present invention, those of ordinary skills, not making under the creative work prerequisite the every other embodiment obtained, belong to the scope of protection of the invention.
Hardware scheme theory diagram of the present invention as shown in Figure 2, mainly comprises: signal synthesizing module 1, power splitter 2, directional coupler 3, width Phase Receiver machine module 5, FPGA Digital IF Processing module 6, cpu controller 7, FLASH storer 9, temperature sensor 10.
Signal synthesizing module is comprised of exciting signal source 11 and local oscillation signal source 12; Width Phase Receiver machine module comprises two frequency mixer and two moduluses (A/D) converter, the first frequency mixer carries out mixing for the road to power splitter 2 outputs as the signal of reference signal and a road signal of local oscillation signal source 12 outputs, and mixer output signal outputs to the first input end mouth of FPGA Digital IF Processing module after the R passage is exaggerated filtering and analog to digital conversion; The second frequency mixer carries out mixing for the road to directional coupler 3 outputs as the signal of measured piece reflected signal and another road signal of local oscillation signal source 12 outputs, and mixer output signal outputs to the second input port of FPGA Digital IF Processing module after A channel is exaggerated filtering and analog to digital conversion.
Communication interface 8 is received cpu controller; Test port 4 is connected to directional coupler 3.
Exciting signal source produces pumping signal, be divided into two-way through power splitter, one tunnel is sent into the R passage as the reference signal and is characterized incident wave, and another road is added to the pumping signal of measured piece as measured piece through directional coupler, and directional coupler is separated the reflection wave of measured piece to send into A channel.The local oscillation signal source produces the fixing local oscillation signal of frequency difference of synchronizeing with exciting signal source, and the signal and the local oscillation signal that enter R passage and A channel carry out fundamental wave mixing, the output intermediate-freuqncy signal.Intermediate-freuqncy signal, through amplification filtering and A/D digitizing, is converted to the digitizing intermediate frequency, and FPGA Digital IF Processing module is carried out I/Q decomposition and filtering to digital intermediate frequency, extracts amplitude information and the phase information of tested network, sends to CPU.CPU obtains the reflection parameters of tested network through ratio computing, error correction.
Before dispatching from the factory, antenna and transmission line tester carry out humid test: set the sweep parameters such as frequency range, number of scan points, it is 3MHz~88Mz that frequency range is set in the present embodiment, and frequency step is 1MHz, and number of scan points is 86.Respectively at different temperature, the present embodiment is 0 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, to tester, use classic method to be calibrated, obtain the error coefficient under different temperatures and be stored in the FLASH storer with document form, file layout as shown in Figure 3.Error coefficient file including content is: initial frequency, frequency step, count, temperature value C1 and corresponding error coefficient item (source coupling, directivity, skin tracking), temperature value C2 and corresponding error coefficient item (source coupling, directivity, skin tracking), temperature value C3 and corresponding error coefficient item (source coupling, directivity, skin tracking), the rest may be inferred.
Antenna and transmission line tester real-time automatic calibrating method are: when tester is started shooting, program to internal memory, and is calculated reading error coefficient file according to the two-dimensional interpolation that current frequency values and current temperature value are carried out error coefficient, obtain suitable error coefficient item.If current temperature value is c, survey frequency point f, now the error coefficient item at Frequency point f place is expressed as follows:
Directivity: Ed (c, f)
Source coupling: Es (c, f)
Skin tracking: Er (c, f)
Error current coefficient solution procedure is as follows:
1. judge the scope of current frequency f
If freqStart+i * freqStep≤f≤freqStart+ (i+1) * freqStep 0≤i≤N-2
If f1=freqStart+i * freqStep
f2=freqStart+(i+1)×freqStep
Current frequency f is positioned at [f
1, f
2] scope, frequency interpolation is calculated will use f
1point and f
2the point data.
2. judge the scope of Current Temperatures c
Read out three temperature values from data file, make Current Temperatures in these three temperature values between certain two, and they are sorted, if ranking results is C1≤C2≤C3, if c≤C2, the data that in the usage data file, temperature C1 and temperature C2 are corresponding are carried out interpolation calculation, if c>C2, the data that in the usage data file, temperature C2 and temperature C3 are corresponding are carried out interpolation calculation.Establish Current Temperatures c≤C2 herein.
3. according to frequency interpolation
Be illustrated in figure 4 in data file the directional error coefficient that temperature C1 is corresponding, the directional error coefficient data at frequency f place draws by the line segment interpolation, as shown in formula (2).Same temperature C1, source, frequency f place coupling, skin tracking error coefficient are as shown in formula (3), (4), and the error coefficient at temperature C2, frequency f place is as shown in formula (5), (6), (7).
Wherein, Ed (C1, f
1): in the error coefficient file, temperature C1, frequency f
1the directional error coefficient at place;
Ed (C1, f
2): in the error coefficient file, temperature C1, frequency f
2the directional error coefficient at place;
Ed (C1, f): interpolation goes out, temperature C1, the directional error coefficient at frequency f place.
Wherein, Es (C1, f
1): in the error coefficient file, temperature C1, frequency f
1the source matching error coefficient at place;
Es (C1, f
2): in the error coefficient file, temperature C1, frequency f
2the source matching error coefficient at place;
Es (C1, f): interpolation goes out, temperature C1, the source matching error coefficient at frequency f place.
Wherein, Er (C1, f
1): in the error coefficient file, temperature C1, frequency f
1the skin tracking error coefficient at place;
Er (C1, f
2): in the error coefficient file, temperature C1, frequency f
2the skin tracking error coefficient at place;
Er (C1, f): interpolation goes out, temperature C1, the skin tracking error coefficient at frequency f place.
Wherein, Ed (C2, f
1): in the error coefficient file, temperature C2, frequency f
1the directional error coefficient at place;
Ed (C2, f
2): in the error coefficient file, temperature C2, frequency f
2the directional error coefficient at place;
Ed (C2, f): interpolation goes out, temperature C2, the directional error coefficient at frequency f place.
Wherein, Es (C2, f
1): in the error coefficient file, temperature C2, frequency f
1the source matching error coefficient at place;
Es (C2, f
2): in the error coefficient file, temperature C2, frequency f
2the source matching error coefficient at place;
Es (C2, f): interpolation goes out, temperature C2, the source matching error coefficient at frequency f place.
Wherein, Er (C2, f
1): in the error coefficient file, temperature C2, frequency f
1the skin tracking error coefficient at place;
Er (C2, f
2): in the error coefficient file, temperature C2, frequency f
2the skin tracking error coefficient at place;
Er (C2, f): interpolation goes out, temperature C2, the skin tracking error coefficient at frequency f place.
4. according to temperature interpolation
Figure 5 shows that at temperature C1, C2, the directional error coefficient at C3 lower frequency f place, can obtain the directional error coefficient at Current Temperatures c place by the line segment interpolation, as formula (8), in like manner can obtain source coupling, the skin tracking error coefficient at temperature c place, as publicity (9), shown in (10).
Wherein, Ed (C1, f): formula (2) interpolation result: temperature C1, the directional error coefficient at frequency f place;
Ed (C2, f): formula (5) interpolation result: temperature C2, the directional error coefficient at frequency f place;
Ed (c, f): interpolation goes out, temperature c, the directional error coefficient at frequency f place.
Wherein, Es (C1, f): formula (3) interpolation result: temperature C1, the source matching error coefficient at frequency f place;
Es (C2, f): formula (6) interpolation result: temperature C2, the source matching error coefficient at frequency f place;
Es (c, f): interpolation goes out, temperature c, the source matching error coefficient at frequency f place.
Wherein, Er (C1, f): formula (4) interpolation result: temperature C1, your error coefficient of the skin tracking at frequency f place;
Er (C2, f): formula (7) interpolation result: temperature C2, the skin tracking error coefficient at frequency f place;
Er (c, f): interpolation goes out, temperature c, the skin tracking error coefficient at frequency f place.
Finally determine under temperature c the error coefficient item at frequency f place by above step.As temperature c, when frequency f changes, 1., 2., 3. repeating step obtains new error coefficient item.
Compared to existing technology, tester of the present invention in use without any need for calibration operation, save time, improve testing efficiency.The automatic calibration algorithm of this tester can carry out error coefficient calculating in real time according to the variation of temperature and set of frequency.
The foregoing is only preferred embodiment of the present invention, in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of doing, be equal to replacement, improvement etc., within all should being included in protection scope of the present invention.