Three-section method for measuring power of ultrashort wave space radiation

Abstract

The application provides a three-section measurement method for ultrashort wave space radiation power, and belongs to the technical field of power amplifier measurement. The method comprises the following steps: dividing the space power synthesis system into an excitation section, an amplification section and a radiation section; wherein the excitation section comprises a signal splitter and a plurality of phase shifters; the signal splitter divides the input signal into a plurality of channels, each channel is provided with at least one phase shifter; the amplification section is provided with a plurality of amplifiers, each amplifier amplifies the output signal of the phase shifter of one channel; the output end of each amplifier is connected to an antenna unit; the radiation section comprises a plurality of antenna units; the amplitude and phase of the excitation signal output by each channel are measured by using an instrument, the amplitude variation and phase deviation of each channel of the excitation section, the amplification section and the radiation section are obtained, and the radiation power of the antenna array in the radiation section radiated to the space is calculated by using an equivalent radiation power formula.

Description

Technical Field

[0001] This invention belongs to the field of power amplifier measurement technology and relates to a three-segment measurement method for ultra-shortwave spatial radiated power. Background Technology

[0002] A space power combining system typically consists of an exciter, a splitter, a phase controller, N phase shifters, N power amplifiers, and unit antennas. Its basic principle is that N unit antennas simultaneously radiate electromagnetic signals into the air. By adjusting the phase of the signals input to the N antenna units, the phases of the N signals arriving at the target receiving point are made consistent, thus superimposing the in-phase strengths of the N signals at that point to achieve space power combining.

[0003] like Figure 1 As shown, the excitation source provides the required excitation signal under the control of the controller. The excitation source signal is split into N paths by a splitter and sent to N phase shifters. Under the control of the phase controller, the phase shifters perform corresponding phase shifts on each signal. The phase controller is a key component in the spatial power combining system. Its main function is to calculate the required phase shift value for each array element signal based on the spatial power combining direction requirements, using a phase control algorithm, given a determined antenna array element and array configuration. This generates a phase control signal to adjust the phase shift amount of the phase shifters, maximizing the spatial combining efficiency of the multiple signals radiated by the antenna array in the target direction.

[0004] Currently, methods for measuring equivalent radiant power through space power synthesis can be categorized into direct measurement methods and comparative measurement methods, depending on whether a reference system is introduced.

[0005] (1) Direct measurement method

[0006] The direct measurement method involves directly measuring the far-field strength of the space power combining system, calculating the far-field radiated power of the device based on a theoretical model, and finally calculating the efficiency of the device using a computer.

[0007] Its main advantage is its simplicity in measurement; it's a crude method for checking the operational status of space power combining equipment, and can be used to verify whether the combined power of the space power combining equipment meets the standards. However, its disadvantages are also quite significant, mainly manifested in:

[0008] (a) The measurement error is large, the requirements for the test site are strict, and the test conditions are very demanding, so it is easily affected by other factors. For example, there may be matching problems when using a measurement antenna at the measurement location, errors caused by attenuation of the antenna feed line to the power meter, and errors in the receiving system directly affect the measurement results;

[0009] (b) only power value can be obtained, other parameters cannot be obtained, and more help cannot be provided for the next maintenance of the device, and in order to obtain other parameters, further detection needs to be performed through other methods, which actually increases workload and difficulty.

[0010] (2) Comparison measurement method

[0011] The comparison measurement method introduces a radiation system with a known parameter as a reference, and sets the reference system and the to-be-measured system under as similar working conditions as possible. The far-field radiation power of the two systems is measured, and the equivalent radiation power of the to-be-measured device is calculated by comparison with the reference system. Since the volume of the ultra-short wave spatial power synthesis system is large, it is usually not measured in the region close to the free space.

[0012] In actual application, the comparison measurement usually adopts two types of time-sharing measurement or frequency division measurement. The time-sharing measurement refers to that the signal frequency of the to-be-measured system and the reference system is the same, and the equivalent radiation power of the to-be-measured system and the reference system is obtained by distinguishing the sequence during measurement. The frequency division measurement refers to that the signal frequency of the to-be-measured system and the reference system is slightly different, which is enough to be distinguished in the receiving system, so that the signal can be transmitted at the same time, and the radiation power of the two signals is measured at the same time in the test system. According to the radiation power of the reference system, the radiation power of the to-be-measured system can be obtained.

[0013] The advantage of the comparison measurement method is that the equivalent radiation power of the to-be-measured system can be obtained simply and intuitively by comparison and calculation of the known parameters of the reference system and the measured data, and the error is smaller than that of the direct measurement method. It is the main method for measuring the equivalent radiation power of the ultra-short wave spatial power synthesis at present. The main shortcomings of the comparison measurement method are:

[0014] (a) the accuracy of the reference system required by the comparison measurement method is difficult to guarantee;

[0015] (b) the working conditions of the reference system and the to-be-measured system are often different, such as the differences in signal transmission path, time division measurement or frequency division measurement;

[0016] (c) the test parameters are often different from the actual working parameters of the system, such as that the test signal usually uses a single frequency signal, while the system working signal is usually a modulated signal, or even a wideband signal, and the single frequency characteristic cannot accurately reflect the characteristics of the antenna array when emitting a wideband signal;

[0017] (d) the comparison measurement method needs to find a device that meets the measurement conditions, and the deployment is complex, and the time and space requirements of the measurement method cannot be met in the experiment and use of the device. SUMMARY

[0018] To solve the above technical problems, the application provides a three-section type measurement method for ultrashort wave space radiation power, which is used for measuring the synthesized electromagnetic signal power radiated to space by a space power synthesis system, and comprises the following steps:

[0019] Step 1: the space power synthesis system is divided into three parts: an excitation section, an amplification section and a radiation section; wherein the excitation section comprises a signal splitter and a plurality of phase shifters; the signal splitter divides the input signal into a plurality of channels, each channel having at least one phase shifter; the amplification section has a plurality of amplifiers, each amplifier amplifying the output signal of the phase shifter of one channel; the output end of each amplifier is connected to an antenna unit; and the radiation section comprises a plurality of antenna units;

[0020] Step 2: the excitation signal is divided into the same frequency excitation signals of a plurality of channels by the signal splitter and injected into the phase shifters, and the amplitude and phase of the excitation signals output by each channel of the excitation section are measured by using an instrument to obtain the amplitude variation and phase offset of each channel of the excitation section;

[0021] Step 3: the amplitude and phase of the output signals of the amplifiers of each channel of the amplification section are measured by using an instrument to obtain the amplitude variation and phase offset of each channel of the amplification section;

[0022] Step 4: the amplitude and phase characteristics of each array element of the antenna array in the radiation section are measured;

[0023] Step 5: based on the measurement results of steps 2, 3 and 4, the equivalent radiation power formula is used to calculate the radiation power of the antenna array radiated to space in the radiation section.

[0024] According to the method, the phase shifters of the excitation section, the amplifiers of the amplification section and the antenna units of the radiation section are connected in series; the phase shifters in one channel of the excitation section comprise at least one phase shift unit connected in series; and the amplifiers in one channel of the amplification section comprise at least one amplification unit connected in series.

[0025] According to the method, the measurement of the amplitude and phase of the excitation signals output by each channel of the excitation section in step 2 comprises the following substeps:

[0026] Step 2.1: the amplitude of the excitation signal is directly measured by using a power meter at the input end and the output end of the phase shifter;

[0027] Step 2.2: the excitation signals output by the output ends of each channel of the phase shifter are subjected to synchronous receiving, collection and then demodulation, and the noise baseband signals are extracted therefrom, and the relative time delay between the channels is calculated by correlation calculation between the noise of different channels;

[0028] Step 2.3: the maximum relative time delay between any two channels is calculated to obtain the phase time delay of the excitation section.

[0029] The step 3 of measuring the amplitude and phase of the excitation signal of each channel output of the amplification section in the method comprises the following sub-steps:

[0030] Step 3.1, a power calibration signal source is connected to the input end of the amplifier, a high-power attenuator is connected to the output end, and a power meter is finally connected, the input power and the output power of the amplifier are measured, and the ratio of the input power and the output power is calculated to determine the gain of the power amplifier;

[0031] Step 3.2, the time delay of each channel is directly read by using a digital wideband storage oscilloscope; and additional errors are eliminated from the directly read time delay of each channel to obtain the real time delay of each channel of the amplification section.

[0032] The step 4 of measuring the amplitude and phase characteristics of each array element of the antenna array in the radiation section in the method comprises the following sub-steps:

[0033] Step 4.1, a multi-channel CDMA signal is used as an excitation signal provided to each array element of the antenna array, and adjacent array elements of the antenna array provide different channels of the excitation signal;

[0034] Step 4.2, the multi-channel CDMA signal is simultaneously received at a test point in a far field by using a multi-channel CDMA receiver, the relative amplitude-frequency characteristics and phase characteristics of the signal generated by the multi-channel CDMA signal at the test point are obtained by separating the multi-channel CDMA signal, and the amplitude-frequency characteristics and phase characteristics of each array element of the antenna array are determined in combination with the position and structure of each array element of the antenna array and the position information of the test point;

[0035] Step 4.3, the radiation parameters of each array element of the antenna array are determined according to the position and structure of each array element of the antenna array and the position of the test point.

[0036] The radiation parameters of each array element of the antenna array in the method comprise the radiation admittance of each array element of the antenna array and the comprehensive amplitude-frequency and phase parameters of each array element of the antenna array.

[0037] The three-section measurement scheme of the application divides the parameters of the spatial power combining system into three independent sub-systems for independent measurement, and has the following main advantages:

[0038] (1) The parameters of the antenna array in the spatial power combining system are relatively stable, the channel parts such as the exciter and the amplifier may need to be repaired frequently, and thus state changes frequently occur, but the measurement of the parameters of these devices can be easily performed in a shelter or indoors, thereby providing an effective means for timely detecting the performance of the devices, and being particularly suitable for application in detection, repair and support of outdoor devices;

[0039] (2) Three-segment measurement can obtain the amplitude and phase parameters of each segment of the system. When the measured equipment state changes, the system can be easily adjusted to the optimal working state through system settings, thereby improving the spatial power synthesis efficiency and maximizing the working performance of the equipment.

[0040] (3) The frequency characteristics of each signal in the three-segment measurement are consistent, and the transmission and reception are simultaneous. As long as the gain of the receiving system is calibrated, there is no need to compare with the reference system, which avoids the error caused by time division or frequency division measurement and the calibration problem of the test reference system, and the reliability is higher. Attached Figure Description

[0041] Figure 1 The composition of existing space power combining systems;

[0042] Figure 2 This is a schematic diagram of the three-segment measurement method proposed in this invention;

[0043] Figure 3 This is a schematic diagram of the cross-correlation method for measuring time delay proposed in this invention;

[0044] Figure 4 This is a schematic diagram of the method for measuring the amplitude gain of a multi-channel power amplifier proposed in this invention;

[0045] Figure 5 This is a schematic diagram of the multi-channel power amplifier delay parameter measurement method proposed in this invention;

[0046] Figure 6 This invention comprises an antenna array radiation characteristic testing system based on CDMA signals. Detailed Implementation

[0047] To solve the above-mentioned technical problems, this invention proposes a new measurement method, such as... Figure 2 As shown, the space power combining system is divided into three segments: excitation segment, amplification segment, and radiation segment. The amplitude and phase parameters of the three segments are measured in three independent steps. After obtaining the specific amplitude and phase parameters of the three segments, the equivalent radiation power of the space power combining system is derived according to the calculation method of equivalent radiation power.

[0048] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0049] This invention proposes a three-segment measurement method for ultra-shortwave space radiated power, used to measure the power of the synthesized electromagnetic signal radiated into space by a space power combining system. The method includes the following steps:

[0050] Step 1, the spatial power combining system is divided into three parts: excitation section, amplification section and radiation section; wherein the excitation section includes: signal splitter and a plurality of phase shifters; wherein the signal splitter divides the input signal into a plurality of channels, each channel has at least one phase shifter, the amplification section has a plurality of amplifiers, each amplifier amplifies the output signal of the phase shifter of one channel; the output end of each amplifier is connected to an antenna unit; the radiation section includes a plurality of antenna units;

[0051] Step 2, the excitation signal is divided into a plurality of channels by the signal splitter, and the same frequency excitation signal is injected into the phase shifter, the amplitude and phase of the excitation signal output by each channel of the excitation section are measured by using the instrument, and the amplitude change and phase shift of each channel of the excitation section are obtained;

[0052] Step 3, the amplitude and phase of the output signal of each channel amplifier of the amplification section are measured by using the instrument, and the amplitude change and phase shift of each channel of the amplification section are obtained;

[0053] Step 4, the amplitude and phase characteristics of each array element of the antenna array in the radiation section are measured;

[0054] Step 5, based on the measurement results of steps 2, 3 and 4, the equivalent radiation power formula is used to calculate the radiation power of the antenna array in the radiation section.

[0055] As shown in the accompanying Figure 2 , the spatial power combining system is first divided into three parts: excitation section, amplification section and radiation section. According to the characteristics of each section, the following four steps are mainly measured:

[0056] (1) The multi-channel same frequency excitation signal is measured, and the amplitude and phase difference of each channel excitation signal is accurately measured;

[0057] (2) The amplitude and phase parameters of the power amplifier are measured, and the amplitude and phase characteristics of the power amplifier are accurately measured by calculation;

[0058] (3) The antenna array part of the spatial power system is measured, and the amplitude and phase characteristics of each array element of the antenna array are accurately measured;

[0059] (4) According to the equivalent radiation power formula, the equivalent radiation power is calculated.

[0060] When the communication is interfered, a noise frequency modulation signal is generally used, and the original excitation source signal can be normalized as

[0061] (1)

[0062] Wherein, is the instantaneous phase change caused by noise modulation, is the carrier frequency, and t represents time.

[0063] After the shunt and the phase shifter, the output of the i channel of the excitation section can be expressed as

[0064] (2)

[0065] where, is the amplitude gain of the i channel of the excitation section, is the phase shift of the i channel of the excitation section.

[0066] Similarly, the output of the i channel of the amplification section can be expressed as

[0067] (3)

[0068] The radiation output of the i array of the radiation section can be expressed as

[0069] (4)

[0070] The signal obtained at the receiving point can be expressed as

[0071] (5)

[0072] where, , is the amplitude gain and the phase shift produced by the i channel of the amplifier group of the amplification section; , is the equivalent amplitude gain and the equivalent phase shift produced by the radiation characteristics of the i channel signal of the antenna array of the radiation section; , is the amplitude gain and the phase shift produced by the i signal after the spatial transmission.

[0073] For an N-element antenna array, we only need to measure , , , , , , combined with the position information of the transmitting and receiving point, to calculate , , we can obtain the received signal

[0074] (6)

[0075] The amplitude of which is

[0076] (7)

[0077] In the formula, the amplitude and time delay characteristics of the first and second sections are , , , The amplitude and time delay characteristics of the radiation section can be obtained by direct measurement 、 The channel characteristics are completely determined by the radiation characteristics of the antenna array and can be further calculated based on the experimentally measured impedance characteristics 、 The time delay characteristics of the transmission path are completely determined by the locations of the transmission and reception points and are known.

[0078] According to the method, the phase shifters in the excitation section, the amplifiers in the amplification section, and the antenna units in the radiation section are connected in series; the phase shifters in one channel of the excitation section include at least one phase shift unit connected in series; and the amplifiers in one channel of the amplification section include at least one amplification unit connected in series.

[0079] According to the method, the measurement of the amplitudes and phases of the excitation signals output by the channels of the excitation section in step 2 includes the following sub-steps:

[0080] Step 2.1, the amplitudes of the excitation signals are directly measured at the input and output ends of the phase shifters using power meters;

[0081] Step 2.2, the excitation signals output by the output ends of the channels of the phase shifters are synchronously received, collected, demodulated, and then the noise baseband signals are extracted therefrom, and the relative time delays between the channels are calculated through correlation calculation between the noise signals of different channels;

[0082] Step 2.3, the maximum relative time delay between any two channels is calculated to obtain the phase time delay of the excitation section.

[0083] As shown in the accompanying Figure 3 , it is a schematic diagram of the cross-correlation method for measuring time delay.

[0084] According to the method, the measurement of the amplitudes and phases of the excitation signals output by the channels of the amplification section in step 3 includes the following sub-steps:

[0085] Step 3.1, a power-calibrated signal source is connected to the input end of the amplifier, a high-power attenuator is connected to the output end, and a power meter is finally connected, the input power and output power of the amplifier are measured, and the ratio of the input power and output power is calculated to determine the gain of the power amplifier;

[0086] Step 3.2, the time delays of the channels are directly read using a digital wideband storage oscilloscope; additional errors are eliminated from the directly read time delays of the channels to obtain the true time delays of the channels of the amplification section.

[0087] As shown in the accompanying Figure 4 , it is a schematic diagram of the method for measuring the amplitude gain of the power amplifier. The accompanying Figure 5 is a schematic diagram of the method for measuring the time delay parameters of the multi-channel power amplifier.

[0088] In the method, the step 4 of measuring the amplitude and phase characteristics of each array element in the radiation section comprises the following sub-steps:

[0089] Step 4.1, using multi-channel CDMA signals as excitation signals to provide each array element of the antenna array, and adjacent array elements provide different excitation signals;

[0090] Step 4.2, simultaneously receiving the multi-channel CDMA signals at the test point in the far field by using a multi-channel CDMA receiver, separating the multi-channel CDMA signals to obtain the relative amplitude-frequency characteristics and phase characteristics of the signals generated by the multi-channel CDMA signals at the test point, and combining the position and structure of each array element of the antenna array and the position information of the test point to determine the amplitude-frequency characteristics and phase characteristics of each array element of the antenna array;

[0091] Step 4.3, determining the radiation parameters of each array element of the antenna array according to the position and structure of each array element of the antenna array and the position of the test point.

[0092] In the method, the radiation parameters of each array element of the antenna array comprise radiation admittance of each array element of the antenna array and comprehensive amplitude-frequency and phase parameters of each array element of the antenna array.

[0093] As shown in the accompanying Figure 6 Fig. 1 is a schematic diagram of an antenna array radiation characteristic test system based on a CDMA signal according to the present application.

[0094] Embodiment

[0095] The specific test method of the three sections is as follows:

[0096] (1) Excitation section: multi-channel homologous noise modulation excitation signal amplitude and phase parameter measurement

[0097] The main signal pattern of the ultra-short wave spatial power synthesis system is a noise frequency modulation signal. The measurement of the amplitude thereof can be directly performed by using a power meter. Here, the problem of measuring the relative time delay of the multi-channel homologous noise modulation excitation signal is mainly solved.

[0098] The measurement of the relative time delay thereof firstly comprises the following steps: synchronously receiving, collecting and demodulating the excitation signal, extracting the noise baseband signal therefrom, and obtaining the relative time delay between channels through the correlation operation between the noises in different channels, so as to obtain an estimation accuracy of about one-tenth of the sampling rate. For example, if the sampling rate is 40 MSPS, the time delay estimation accuracy is about 2.5 ns. Further using the carrier phase extraction information to assist the time delay measurement, the time delay estimation accuracy can be further improved by about one order of magnitude.

[0099] The signal of the multi-channel excitation signal source is a single signal that has been split into multiple signals. Therefore, these multiple signals are regarded as the same signal with time delay differences. Thus, the phase delay measurement of the multi-channel noise FM signal is obtained by performing cross-correlation calculation on the two signals to find the time delay between the channels.

[0100] (8)

[0101] (9)

[0102] Among them, R Nij (τ) is the noise of the i-th path n i (t) and the j-th noise n j The cross-correlation function of (t-Δt), R cij (τ) is the i-th carrier wave With the j-th carrier The cross-correlation function, according to the properties of the autocorrelation function, R Nij (τ), R cij (τ) in Take the maximum value at time, so that it can be obtained from R. Nij (τ), R cij The peak position of (τ) corresponds to The delay of the i-th noise or signal signal is measured. .

[0103] (2) Amplification section: Measurement of amplitude and phase parameters of multi-channel power amplifier group

[0104] The amplitude and phase characteristics of the amplification section include the output power gain and phase delay of each channel. The output power can be measured individually using a high-power attenuator and a power meter. The delay measurement of the power amplifier is performed using a method based on multiple cross-measurements of the BPSK signal.

[0105] By setting the oscilloscope's trigger mode to positive pulse width trigger and setting the trigger condition to a pulse width greater than 60% of the entire carrier cycle, the surrounding phase modulation point signals can be obtained stably. Then, the oscilloscope's software can be used to amplify, widen, and unify the bias, thereby easily obtaining the measured time delay value. The relative time delay of each channel of the oscilloscope, the relative time delay between different connecting cables, and the relative time delay between power dividers can be obtained through a single calculation.

[0106] (a) Method for measuring amplitude and gain of multi-channel power amplifiers

[0107] The measurement of power amplifier output power is relatively simple, only need to connect the input of power amplifier to the signal source of power calibration, the output to the high power attenuator, and finally to the power calibration device to measure the power amplifier power value, and then through simple calculation can get the gain of power amplifier. The measurement method is shown in Figure 4 .

[0108] Assume the power of the signal source is P s (dBW), the gain of the nth power amplifier is G n (dB), the gain of the high power attenuator is M (dB), and the measurement value of the nth power meter is D n (dBW). At this time, we have (10)

[0109] From the above formula, the gain value G n of the nth power amplifier channel can be obtained, that is, the amplitude parameter of the power amplifier.

[0110] (b) Measurement method of multi-channel power amplifier delay parameter

[0111] As shown in Figure 5 , the digital storage oscilloscope DSO can achieve a sampling rate of 120 Gsps, and the instantaneous bandwidth can reach more than 12 GHz. Because the BPSK modulated signal has very obvious time domain characteristics, combined with the high-speed data acquisition and storage capability of the digital wideband storage oscilloscope, it is feasible to use the digital wideband storage oscilloscope to directly observe the time delay of each channel in the time domain.

[0112] From Figure 4 and Figure 5 , it can be known that the relative time delay between the four channels is mainly composed of two parts: one is the transmission characteristics of the power amplifier; the other is the time delay between the channels of the oscilloscope, the attenuator, the power divider, and the inconsistency of the connection between the devices. The former is the measurement result we need, and the latter is the measurement additional error. When measuring high-precision time difference above nanoseconds, the additional error needs to be eliminated through calibration before or during measurement.

[0113] (3) Radiating section: measurement of amplitude and phase parameters of antenna array in space power system

[0114] At the frequency of ultrashort wave, the log-periodic antenna array has a relatively large volume and cannot be measured by the microwave anechoic chamber like other small antenna arrays.

[0115] The multiple CDMA signals are used as the excitations of the elements of the antenna array, the multiple channel receiver is used to simultaneously receive and separate the multiple CDMA signals in the far field, the relative amplitude and phase characteristics of the signals generated by the excitations at the test point are obtained, the radiation characteristic parameters of the antenna array are solved by combining the position and structure of the antenna array and the position information of the test point, and the system composition is as shown in Figure 6 .

[0116] For an N-element antenna array, the radiation equation of the antenna array can be expressed as

[0117] (11)

[0118] In the formula, , , the distributed current vector, the excitation voltage vector and the characteristic admittance matrix of the antenna array are respectively. The distributed current vector of the first element is denoted as , the excitation voltage vector of the first element is denoted as , and the mutual admittance matrix between the first element and the second element is denoted as , so that

[0119] (12)

[0120] In the formula, , the distributed current and the excitation voltage of the first element are respectively, the mutual admittance between the first element and the second element is

[0121] , (13)

[0122] In the formula, K is the number of elements of each element. According to the reciprocity principle, there is

[0123] (14)

[0124] Since the array structure and the element structure of the large-size antenna array are usually regular, there are a large number of in the formula are the same. That is, the complexity of is far lower than that of the diagonal matrix. Assuming that the excitation voltage of the first element is , then ​​​​​​​​​​​​may be expressed as

[0125] (15)

[0126] In the far field, the signal that the receiving point can detect may be expressed as

[0127] (16)

[0128] wherein, is the electric wave transmission characteristic parameter of the antenna array, and is related to the transmission path between the transmitting point and the receiving point and the antenna array structure. Obviously, there is

[0129] (17)

[0130] (18)

[0131] wherein, The first signal generated by the array element, is the electric wave transmission characteristic parameter of the first array element to the test point, and can be expressed as

[0132] (19)

[0133] (20)

[0134] wherein, is the electric wave transmission characteristic parameter of the first array element, is the signal generated by the first unit, is the electric wave transmission characteristic parameter of the first array element to the test point.

[0135] When receiving using a CDMA receiver, the signals emitted by all the excitation units are received simultaneously, and thus the received signal may be expressed as

[0136] (21)

[0137] wherein, is the equivalent admittance of the antenna array to the first path excitation, and not only contains the radiation characteristic of the antenna array, but also is related to the signal transmission path.

[0138] As can be seen from equation (21), if the excitation of the antenna array and the electric wave transmission characteristic between the transmitting point and the receiving point are known, as long as each path excitation The generated radiation signal The equivalent excitation radiation admittance parameters of the test point can be solved .

[0139] Due to the use of the multi-channel CDMA signal excitation, the CDMA receiver can not only separate the received signals at the receiving end , but also can detect the amplitude difference and phase difference between and with high precision. Combined with the mature high-precision positioning technology, through multi-point testing, the equation group is established, and the radiation admittance of the antenna array is solved, and then the comprehensive amplitude and phase characteristics of each array element , , .

[0140] (4) The equivalent radiation power is calculated according to the equivalent radiation power formula.

[0141] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application and are not limited. Although the embodiments of the present application have been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that the technical solutions of the embodiments of the present application can be modified or replaced without departing from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A three-section method for measuring the power of the ultra-short wave space radiation, for measuring the power of the synthesized electromagnetic signal radiated into space by a space power synthesis system, characterized in that, The method comprises: Step 1, the spatial power synthesis system is divided into: excitation section, amplification section and radiation section; wherein the excitation section comprises: signal splitter and a plurality of phase shifters; wherein the signal splitter divides the input signal into a plurality of channels, each channel has at least one phase shifter, the amplification section has a plurality of amplifiers, each amplifier amplifies the output signal of the phase shifter of one channel; the output end of each amplifier is connected with an antenna unit; the radiation section comprises a plurality of antenna units; Step 2, the excitation signal is divided into a plurality of channels of the same frequency excitation signal through the signal splitter and injected into the phase shifter, the amplitude and phase of the excitation signal output by each channel of the excitation section are measured, and the amplitude variation and phase offset of each channel of the excitation section are obtained; Step 3, the amplitude and phase of the output signal of each channel amplifier of the amplification section are measured, and the amplitude variation and phase offset of each channel of the amplification section are obtained; Step 4, the amplitude and phase characteristics of each array element in the antenna array of the radiation section are measured; Step 5, based on the measurement results of steps 2-4, the equivalent radiation power formula is used to calculate the radiation power of the antenna array in the radiation section radiated to the space; Wherein, the amplitude and phase of the excitation signal in step 2 are measured in detail as follows: Step 2.1, directly use the power meter to measure the amplitude of the excitation signal at the input end and the output end of the phase shifter; Step 2.2, perform synchronous receiving, collection and then demodulation on the excitation signal output from the output end of each channel of the phase shifter, extract the noise baseband signal therefrom, and calculate the relative time delay between the channels through the correlation calculation between the noises of different channels; Step 2.3, calculate the maximum relative time delay between any two channels to obtain the phase delay of the excitation section; Wherein, the amplitude and phase of the output signal in step 3 are measured in detail as follows: Step 3.1, connect the power calibration signal source at the input end of the amplifier, connect the high-power attenuator at the output end, and finally connect the power meter, measure the input power and output power of the amplifier, and calculate the ratio of the input power and the output power to determine the gain of the power amplifier; Step 3.2, directly read the time delay of each channel by using a digital wideband storage oscilloscope; eliminate the additional error from the directly read time delay to obtain the real time delay of each channel of the amplification section; Wherein, the amplitude and phase characteristics of each array element in step 4 are measured in detail as follows: Step 4.1, use multiple CDMA signals as excitation signals to provide each array element of the antenna array, and adjacent array elements provide different excitation signals; Step 4.2, simultaneously receive the multiple CDMA signals at the test point in the far field by using a multi-channel CDMA receiver, separate the multiple CDMA signals to obtain the relative amplitude-frequency characteristics and phase characteristics of the signals generated by the multiple CDMA signals at the test point, and determine the amplitude-frequency characteristics and phase characteristics of each array element of the antenna array in combination with the position and composition structure of each array element of the antenna array and the position information of the test point; Step 4.3, determine the radiation parameters of each array element of the antenna array according to the position and composition structure of each array element of the antenna array and the test point.

2. The method of claim 1, wherein, The phase shifter of the excitation section, the amplifier of the amplification section and the antenna unit of the radiation section are connected in series.

3. The method of claim 2, wherein, The radiation parameters of each array element of the antenna array include radiation admittance of each array element of the antenna array and comprehensive amplitude-frequency and phase parameters of each array element of the antenna array.

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