Method for testing fundamental wave of pulse transmitter in antenna port conducted transmission

Abstract

The invention discloses a method for testing fundamental waves of a pulse transmitter in antenna port conducted emission, and the method comprises the steps: sequentially connecting a to-be-tested pulse transmitter, an attenuator and a scanning receiver through a cable, and obtaining a test equipment group; enabling the to-be-tested pulse transmitter to enter a stable working state, and transmitting a working signal with a preset working frequency; scanning parameters of the scanning type receiver are adjusted, and the maximum indicated value of the fundamental wave power level under the working frequency is obtained; prolonging the first scanning time as second scanning time, repeating the process after the preset first scanning time, and circulating for several times until the signal spectral line is completely displayed; determining that the harmonic and messy emission level output comes from the pulse transmitter to be tested instead of the test equipment group; and comparing whether the harmonic value and the spurious emission level value meet a preset test standard or not. The accurate measurement of the fundamental wave level plays a decisive role in a CE106 test item, and the method can effectively solve the problems of discontinuous fundamental wave spectrum display and inaccurate level measurement of the pulse transmitter.

Description

Technical Field

[0001] The invention relates to the technical field of signal measurement, in particular to a method for testing a fundamental wave of a pulse transmitter in antenna port conduction transmission. Background Art

[0002] The name of CE106 project in GJB151B is 10kHz~40GHz antenna port conducted emission. The purpose of the test is to detect and verify that the harmonic emission and spurious emission interference radiated outward from the antenna port of the test equipment (EUT) should not exceed the limit specified in the standard. GJB151B-2013 stipulates the limit values ​​of the conducted emission of the antenna port of the test equipment in three cases, respectively for the three cases of the test equipment. Among them, when the test equipment belongs to the receiver state and the transmitter and amplifier (standby state), the limit value is a fixed limit of 34dBμV; when the test equipment is in the transmitter and amplifier (transmitting state), the limit value of the antenna port conducted emission specified in the standard is: except for the second and third harmonics, all harmonic emissions and spurious emissions are at least 80dB lower than the fundamental level, and the second and third harmonics should be suppressed to -20dBm or 80dB lower than the fundamental level, whichever has the smaller suppression requirement. The accurate measurement of the fundamental wave level in the transmitter and amplifier (transmitting state) in the CE106 project is a key factor in determining the limit value. The main test instruments used for fundamental wave testing are measuring receivers and attenuators. The function of the attenuator is to attenuate the fundamental wave power of the device under test to ensure that the power received by the measuring receiver is not higher than the maximum tolerable input power. However, the fundamental wave power measurement method given in the GJB151B standard is only applicable to continuous wave power measurement. With the widespread application of pulse power amplifiers in electronic equipment, the method in the standard is no longer applicable to the measurement of pulse power, and the accurate measurement of pulse peak power determines the accuracy and reliability of the CE106 test project. The fundamental wave power measurement in the high-power transmission state has the problems of the upper limit of the equipment test power tolerance and inaccurate pulse spectrum measurement. Therefore, it is urgent to solve the problem of the accuracy and reliability of the measurement of the fundamental wave pulse power in the CE106 test project when the device under test is a pulse transmitter. Summary of the invention

[0003] The invention provides a method for testing the fundamental wave of a pulse transmitter in the conducted emission of an antenna port, and solves the problem that the CE106 test method in the existing GJB151B-2013 is mainly applicable to the measurement of a continuous wave signal transmitter, but not applicable to a pulse transmitter. When the fundamental wave level of a pulse signal (the maximum power value of a pulse signal of a pulse transmitter to be tested) is measured according to the method specified in GJB151B, a scan leakage problem may occur.

[0004] In a first aspect, an embodiment of the present invention provides a method for testing a fundamental wave of a pulse transmitter in a conducted transmission of an antenna port, wherein the duty cycle of the pulse transmitter is greater than 10%, and the method comprises:

[0005] Connecting the pulse transmitter, attenuator, and scanning receiver to be tested in sequence through cables to obtain a test equipment set;

[0006] Make the pulse transmitter to be tested enter a stable working state and send out a working signal of a preset working frequency;

[0007] Adjust the scanning parameters of the scanning receiver to obtain the maximum indication value of the fundamental wave power level at the operating frequency;

[0008] Preset a first scanning time, use the scanning receiver to receive the working signal to obtain a signal spectrum line, determine whether the waveform of the signal spectrum line is obviously depressed, broadened and delayed, if not, record the power level of the working frequency and the bandwidth and scanning time of the scanning receiver; if yes, extend the first scanning time to a second scanning time, repeat the process after the preset first scanning time, and cycle several times until the signal spectrum line is completely displayed;

[0009] Maintain the bandwidth and scanning time of the scanning receiver until the signal spectrum is fully displayed, scan the frequency value to be measured and record all harmonic values ​​and spurious emission level values;

[0010] Verify that harmonic and spurious emission level outputs are coming from the pulse transmitter under test and not the test equipment set;

[0011] Compare the harmonic values ​​and spurious emission level values ​​to see whether they meet the preset test standards; if so, the test result of the pulse transmitter to be tested is passed; otherwise, the test result of the pulse transmitter to be tested is failed.

[0012] In a second aspect, an embodiment of the present invention provides a method for testing a fundamental wave of a pulse transmitter in a conducted transmission of an antenna port, wherein the duty cycle of the pulse transmitter is less than or equal to 10%, and the method comprises:

[0013] Connecting the pulse transmitter to be tested, the attenuator and the time-domain gated receiver in sequence through cables to obtain a test equipment set;

[0014] Make the pulse transmitter to be tested enter a stable working state and send out a working signal of a preset working frequency;

[0015] Adjust the scanning parameters of the time domain gated receiver to obtain the maximum indication value of the fundamental wave power level at the operating frequency;

[0016] Preset the trigger delay and trigger time length of the time domain gating of the time domain gating receiver so that the triggering moment is exactly the moment when the pulse modulation signal of the pulse transmitter to be tested appears;

[0017] Setting the trigger of the time domain gated receiver to pulse trigger, whose frequency is the carrier frequency of the pulse signal of the pulse transmitter to be tested;

[0018] Within the permitted range, setting the bandwidth of the time-domain gated receiver to its maximum bandwidth;

[0019] Setting the scanning period of the time domain gated receiver to be at least two complete pulse signal periods of the pulse transmitter to be tested;

[0020] Keep the triggering moment of the time domain gated receiver exactly synchronized with the moment when the pulse modulation signal of the pulse transmitter to be tested appears, and maintain the bandwidth and scanning period of the time domain gated receiver, scan the frequency value to be tested of the pulse transmitter to be tested and record all harmonic values ​​and spurious emission level values;

[0021] Verify that harmonic and spurious emission level outputs are coming from the pulse transmitter under test and not the test equipment set;

[0022] Compare the harmonic values ​​and spurious emission level values ​​to see whether they meet the preset test standards; if so, the test result of the pulse transmitter to be tested is passed; otherwise, the test result of the pulse transmitter to be tested is failed.

[0023] In some embodiments of the first aspect or the second aspect, the step of making the transmitter to be tested enter a stable working state is achieved by powering on and preheating in advance.

[0024] In some embodiments of the first aspect or the second aspect, the step of confirming that the harmonics and spurious conducted emission levels at the antenna port come from the transmitter to be tested rather than the test equipment group is included, specifically, scanning is performed by a scanning receiver or a time-domain gated receiver when the pulse transmitter is in standby mode. If the scanning receiver or the time-domain gated receiver does not display a signal, it is determined that the accurate measurement values ​​of the harmonics and the accurate measurement values ​​of the spurious conducted emission levels come from the transmitter to be tested.

[0025] In some embodiments of the first aspect or the second aspect, the scanning parameters include receiver bandwidth, measurement time, fundamental wave scanning frequency range, scanning step and input attenuation, and the input attenuation includes attenuation coefficient and insertion loss.

[0026] In some embodiments of the first aspect or the second aspect, the pulse transmitter includes an amplifier, to which a signal of appropriate frequency, amplitude and modulation is input according to the equipment specifications, and the harmonics and spurious emissions of the signal are at least 6dB lower than the limit.

[0027] In some embodiments, the parameters of the pulse transmitter and the amplifier are variable, and the emission spectrum of the pulse transmitter and the amplifier at full power output is selected as the emission spectrum value to be measured.

[0028] In some embodiments, the attenuation coefficient and the insertion loss are obtained by testing with a vector network analyzer.

[0029] In some embodiments, the fundamental wave scanning frequency range is specifically ±5% of the working signal bandwidth or ±5% of the working signal fundamental frequency, whichever is larger.

[0030] In some embodiments of the first aspect or the second aspect, the preset test standard is specifically set according to GJB151B-2013, that is, when the transmitter to be tested is in a stable working state, the second harmonic and third harmonic emissions in the accurate measurement values ​​of the harmonics are not greater than -20dBm or lower than 80dB of the fundamental level of the operating frequency f0, whichever is higher, and all other accurate measurement values ​​of the harmonics and accurate measurement values ​​of the spurious conducted emission levels are less than 80dB of the peak value of the fundamental level of the operating frequency f0.

[0031] The advantages of the present invention are:

[0032] The accurate measurement of the fundamental wave level plays a decisive role in the CE106 test project. The method of the present invention can effectively solve the problem of discontinuous display of the fundamental wave spectrum of the pulse transmitter and inaccurate level measurement.

[0033] According to the duty cycle of the pulse signal of the pulse transmitter to be tested, there are two test methods:

[0034] 1. For the case where the duty cycle of the pulse transmitter is greater than 10%, the method adopted is to extend the scanning time and accurately measure the fundamental wave level of the pulse transmitter to be tested, and then determine the limit of the conducted emission of the EUT antenna port and accurately complete the CE106 project test;

[0035] 2. For the case where the duty cycle of the pulse transmitter is less than or equal to 10%, the trigger time and trigger time length of the time domain gating of the time domain gating receiver are set so that the trigger moment is exactly the moment when the pulse modulation signal appears, and the scanning period of the time domain gating receiver is set to accurately measure the fundamental wave level of the pulse transmitter to be tested. Only then can the limit of the conducted emission of the EUT antenna port be determined and the CE106 project test be accurately completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the structure of a pulse signal fundamental wave test equipment group according to an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of a method flow chart of Embodiment 1 of the present invention;

[0038] Figure 3 This is a schematic diagram of the method flow of Embodiment 2 of the present invention.

[0039] In the figure: 1- Equipment under test, i.e., the pulse transmitter under test (EUT); 2- Attenuator; 3- Scanning receiver or time-domain gated receiver. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is further described below in conjunction with specific implementation methods.

[0041] Embodiment 1

[0042] The embodiment of the present invention provides a method for testing the fundamental wave of a pulse transmitter in the conducted transmission of an antenna port, wherein the duty cycle of the pulse transmitter is greater than 10%, and the method comprises:

[0043] Connecting the pulse transmitter, attenuator, and scanning receiver to be tested in sequence through cables to obtain a test equipment set;

[0044] Make the pulse transmitter to be tested enter a stable working state and send out a working signal of a preset working frequency;

[0045] Make the transmitter under test enter a stable working state by powering on and preheating it in advance.

[0046] Adjust the scanning parameters of the scanning receiver to obtain the maximum indication value of the fundamental wave power level at the working frequency; scanning parameters include receiver bandwidth, measurement time, fundamental wave scanning frequency range, scanning step and input attenuation. Input attenuation includes attenuation coefficient and insertion loss. The attenuation coefficient and insertion loss are obtained by testing with a vector network analyzer. The fundamental wave scanning frequency range is specifically the larger range of ±5% of the working signal bandwidth or ±5% of the working signal fundamental frequency.

[0047] A first scanning time is preset, and the scanning receiver is used to receive the working signal to obtain a signal spectrum line, and it is determined whether the waveform of the signal spectrum line is obviously depressed, broadened, and delayed. If not, the power level of the working frequency and the bandwidth and scanning time of the scanning receiver are recorded; if so, the first scanning time is extended to a second scanning time, and the process after the preset first scanning time is repeated for several times until the signal spectrum line is completely displayed; therefore, extending the scanning time can effectively prevent amplitude distortion.

[0048] Keep the bandwidth and scanning time of the scanning receiver until the signal spectrum is fully displayed, scan the frequency value to be measured and record all harmonic values ​​and spurious emission level values, that is, record the fundamental frequency (f o )'s power level and the measurement receiver bandwidth and scanning time; read out the maximum power value (that is, the spurious emission level value) corresponding to the frequency value of the pulse transmitter to be tested.

[0049] Confirm that the harmonic and spurious emission level outputs come from the pulse transmitter under test rather than the test equipment group. The specific steps are to scan through a scanning receiver or a time-domain gated receiver when the pulse transmitter is in standby state. If the scanning receiver or the time-domain gated receiver does not display a signal, it is determined that the accurate measurement values ​​of the harmonics and the accurate measurement values ​​of the spurious conducted emission levels come from the transmitter under test.

[0050] Compare the harmonic values ​​and spurious emission level values ​​to see if they meet the preset test standards; if they do, the test result of the pulse transmitter to be tested is passed, otherwise the test result of the pulse transmitter to be tested is failed. The preset test standard is specifically set according to GJB151B-2013, that is, when the transmitter to be tested is in a stable working state, the second harmonic and third harmonic emissions in the harmonic accurate measurement values ​​are not greater than -20dBm or lower than the working frequency f0 fundamental level 80dB, whichever is higher, and all other harmonic accurate measurement values ​​and spurious conducted emission level accurate measurement values ​​are less than 80dB of the peak value of the working frequency f0 fundamental level.

[0051] In some preferred embodiments, the pulse transmitter includes an amplifier, to which a signal of suitable frequency, amplitude and modulation is input according to the equipment specifications, and the harmonic and spurious emissions of the signal are at least 6 dB lower than the limit.

[0052] In some preferred embodiments, the parameters of the pulse transmitter and the amplifier are variable, and the emission spectrum of the pulse transmitter and the amplifier at full power output is selected as the emission spectrum value to be measured.

[0053] Embodiment 2

[0054] The embodiment of the present invention provides a method for testing the fundamental wave of a pulse transmitter in the conducted transmission of an antenna port, wherein the duty cycle of the pulse transmitter is less than or equal to 10%, and the method comprises:

[0055] Connecting the pulse transmitter to be tested, the attenuator and the time-domain gated receiver in sequence through cables to obtain a test equipment set;

[0056] Make the pulse transmitter to be tested enter a stable working state and send out a working signal with a preset working frequency; make the transmitter to be tested enter a stable working state by powering on and preheating in advance.

[0057] Adjust the scanning parameters of the time domain gated receiver to obtain the maximum indication value of the fundamental wave power level at the working frequency; scanning parameters include receiver bandwidth, measurement time, fundamental wave scanning frequency range, scanning step and input attenuation. Input attenuation includes attenuation coefficient and insertion loss. The attenuation coefficient and insertion loss are obtained by testing with a vector network analyzer. The fundamental wave scanning frequency range is the larger of ±5% of the working signal bandwidth or ±5% of the working signal fundamental frequency.

[0058] Preset the trigger delay and trigger time length of the time domain gating of the time domain gating receiver so that the triggering moment is exactly the moment when the pulse modulation signal of the pulse transmitter to be tested appears;

[0059] Setting the trigger of the time domain gated receiver to pulse trigger, whose frequency is the carrier frequency of the pulse signal of the pulse transmitter to be tested;

[0060] Within the permitted range, set the bandwidth of the time-domain gated receiver to its maximum bandwidth;

[0061] Setting the scanning period of the time domain gated receiver to be at least two complete pulse signal periods of the pulse transmitter to be tested;

[0062] Keep the triggering moment of the time domain gated receiver synchronized with the moment when the pulse modulation signal of the pulse transmitter to be tested appears, and maintain the bandwidth and scanning period of the time domain gated receiver, scan the frequency value to be tested of the pulse transmitter to be tested and record all harmonic values ​​and spurious emission level values; read out the maximum power value (that is, the spurious emission level value) corresponding to the frequency value to be tested of the pulse transmitter to be tested.

[0063] Confirm that the harmonic and spurious emission level outputs come from the pulse transmitter to be tested rather than the test equipment group, specifically, scanning through a scanning receiver or a time-domain gated receiver when the pulse transmitter is in standby mode, and if the scanning receiver or the time-domain gated receiver does not display a signal, it is determined that the accurate measurement value of the harmonic and the accurate measurement value of the spurious conducted emission level come from the transmitter to be tested. ;

[0064] Compare the harmonic values ​​and spurious emission level values ​​to see if they meet the preset test standards; if they do, the test result of the pulse transmitter to be tested is passed, otherwise the test result of the pulse transmitter to be tested is failed. The preset test standard is specifically set according to GJB151B-2013, that is, when the transmitter to be tested is in a stable working state, the second harmonic and third harmonic emissions in the harmonic accurate measurement values ​​are not greater than -20dBm or lower than the working frequency f0 fundamental level 80dB, whichever is higher, and all other harmonic accurate measurement values ​​and spurious conducted emission level accurate measurement values ​​are less than 80dB of the peak value of the working frequency f0 fundamental level.

[0065] In some preferred embodiments, the pulse transmitter includes an amplifier, to which a signal of suitable frequency, amplitude and modulation is input according to the equipment specification, and the harmonic and spurious emissions of the signal are at least 6 dB lower than the limit.

[0066] In some preferred embodiments, the parameters of the pulse transmitter and the amplifier are variable, and the emission spectrum of the pulse transmitter and the amplifier at full power output is selected as the emission spectrum value to be measured.

[0067] A specific example is given to illustrate the test and operation process of a pulse receiver with a duty cycle less than or equal to 10% as follows:

[0068] 1. The carrier of the pulse signal of the pulse receiver under test (EUT) is 1GHZ, the pulse modulation waveform is 2ms pulse width, and the duty cycle is 5%. Set the trigger of the time domain gated receiver to pulse trigger, and the center frequency of the receiver to the carrier frequency of the pulse signal (i.e. 1GHz).

[0069] 2. The setting of span is determined by the upper bandwidth limit of the real-time function of the time-domain gated receiver. A wider bandwidth should be set within the allowed range.

[0070] 3. The sweep time is set to at least two complete signal cycles; the pulse modulation waveform of the pulse receiver to be tested has a pulse width of 2ms and a duty cycle of 5%, so one cycle is 2ms / 0.05=40ms.

[0071] 4. Adjust the trigger delay and trigger time of the time domain gated receiver so that the moment when the pulse signal appears is exactly the starting moment of the time domain gated receiver screen.

[0072] 5. Measure and read the maximum power value corresponding to the frequency value to be measured of the pulse transmitter (that is, the required fundamental wave level).

Claims

1. A method for testing the fundamental wave of a pulse transmitter in antenna port conducted transmission, characterized in that: The pulse transmitter has a duty cycle greater than 10%, and the method comprises: Connecting the pulse transmitter, attenuator, and scanning receiver to be tested in sequence through cables to obtain a test equipment set; Make the pulse transmitter to be tested enter a stable working state and send out a working signal of a preset working frequency; Adjust the scanning parameters of the scanning receiver to obtain the maximum indication value of the fundamental wave power level at the operating frequency; Preset a first scanning time, use the scanning receiver to receive the working signal to obtain a signal spectrum line, determine whether the waveform of the signal spectrum line is obviously depressed, broadened and delayed, if not, record the power level of the working frequency and the bandwidth and scanning time of the scanning receiver; if yes, extend the first scanning time to a second scanning time, repeat the process after the preset first scanning time, and cycle several times until the signal spectrum line is completely displayed; Maintain the bandwidth and scanning time of the scanning receiver until the signal spectrum is fully displayed, scan the frequency value to be measured and record all harmonic values ​​and spurious emission level values; Verify that harmonic and spurious emission level outputs are coming from the pulse transmitter under test and not the test equipment set; Compare the harmonic values ​​and spurious emission level values ​​to see whether they meet the preset test standards; if so, the test result of the pulse transmitter to be tested is passed; otherwise, the test result of the pulse transmitter to be tested is failed.

2. A method for testing the fundamental wave of a pulse transmitter in antenna port conducted transmission, characterized in that: The pulse transmitter duty cycle is less than or equal to 10%, and the method comprises: Connecting the pulse transmitter to be tested, the attenuator and the time-domain gated receiver in sequence through cables to obtain a test equipment set; Make the pulse transmitter to be tested enter a stable working state and send out a working signal of a preset working frequency; Adjust the scanning parameters of the time domain gated receiver to obtain the maximum indication value of the fundamental wave power level at the operating frequency; Preset the trigger delay and trigger time length of the time domain gating of the time domain gating receiver so that the triggering moment is exactly the moment when the pulse modulation signal of the pulse transmitter to be tested appears; Setting the trigger of the time domain gated receiver to pulse trigger, whose frequency is the carrier frequency of the pulse signal of the pulse transmitter to be tested; Within the permitted range, setting the bandwidth of the time-domain gated receiver to its maximum bandwidth; Setting the scanning period of the time domain gated receiver to be at least two complete pulse signal periods of the pulse transmitter to be tested; Keep the triggering moment of the time domain gated receiver exactly synchronized with the moment when the pulse modulation signal of the pulse transmitter to be tested appears, and maintain the bandwidth and scanning period of the time domain gated receiver, scan the frequency value to be tested of the pulse transmitter to be tested and record all harmonic values ​​and spurious emission level values; Verify that harmonic and spurious emission level outputs are coming from the pulse transmitter under test and not the test equipment set; Compare the harmonic values ​​and spurious emission level values ​​to see whether they meet the preset test standards; if so, the test result of the pulse transmitter to be tested is passed; otherwise, the test result of the pulse transmitter to be tested is failed.

3. The method for testing the fundamental wave of a pulse transmitter in antenna port conducted transmission according to claim 1 or 2, characterized in that: The step of making the transmitter to be tested enter a stable working state is achieved by powering on and preheating in advance.

4. The method for testing the fundamental wave of a pulse transmitter in the conducted emission of an antenna port according to claim 1 or 2, characterized in that: The method also includes the step of confirming that the harmonics and spurious conducted emission levels at the antenna port are from the transmitter to be tested rather than the test equipment group, specifically, scanning is performed by a scanning receiver or a time-domain gated receiver when the pulse transmitter is in standby mode. If the scanning receiver or the time-domain gated receiver does not display a signal, it is determined that the accurate measurement values ​​of the harmonics and the accurate measurement values ​​of the spurious conducted emission levels are from the transmitter to be tested.

5. The method for testing the fundamental wave of a pulse transmitter in antenna port conducted transmission according to claim 1 or 2, characterized in that: The scanning parameters include receiver bandwidth, measurement time, fundamental wave scanning frequency range, scanning step and input attenuation, and the input attenuation includes attenuation coefficient and insertion loss.

6. The method for testing the fundamental wave of a pulse transmitter in antenna port conducted transmission according to claim 1 or 2, characterized in that: The pulse transmitter includes an amplifier, to which a signal of suitable frequency, amplitude and modulation is input according to the equipment specifications, and the harmonic and spurious emissions of the signal are at least 6dB lower than the limit.

7. The method for testing the fundamental wave of a pulse transmitter in the conducted transmission of an antenna port according to claim 6, characterized in that: The parameters of the pulse transmitter and the amplifier are variable, and the emission spectrum of the pulse transmitter and the amplifier when they are output at full power is selected as the emission spectrum value to be measured.

8. The method for testing the fundamental wave of a pulse transmitter in antenna port conducted transmission according to claim 5, characterized in that: The attenuation coefficient and insertion loss are obtained by testing with a vector network analyzer.

9. The method for testing the fundamental wave of a pulse transmitter in antenna port conducted transmission according to claim 5 or 8, characterized in that: The fundamental wave scanning frequency range is specifically ±5% of the working signal bandwidth or ±5% of the working signal fundamental frequency, whichever is larger.

10. The method for testing the fundamental wave of a pulse transmitter in antenna port conducted transmission according to claim 1 or 2, characterized in that: The preset test standard is specifically set according to GJB151B-2013. When the transmitter to be tested is in a stable working state, the second harmonic and third harmonic emissions in the accurate measurement values ​​of the harmonics are not greater than -20dBm or lower than 80dB of the fundamental level of the operating frequency f0, whichever is higher, and all other accurate measurement values ​​of harmonics and accurate measurement values ​​of spurious conducted emission levels are less than 80dB of the peak value of the fundamental level of the operating frequency f0.

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