A calibration method for amplitude and phase consistency of the transmitting channels of a digital phased array

Abstract

The present invention discloses a method for calibrating the amplitude-phase consistency of the transmitting channels of a digital phased array, including: S1. Generating a transmitting calibration signal, and after passing through N transmitting channels of the digital phased array respectively, detecting the amplitude information and phase information of the output signals of each transmitting channel; S2. Selecting the first transmitting channel of the digital phased array as the reference transmitting channel, and calculating the amplitude difference and phase difference of the 2nd to Nth transmitting channels relative to the reference transmitting channel; S3. Fitting the relationship functions of the amplitude difference and phase difference between the 2nd to Nth transmitting channels and the reference transmitting channel changing with temperature in each temperature segmentation interval; S4. According to the actual temperature, calculating the phase difference and amplitude difference of the 2nd to Nth transmitting channels relative to the reference channel, and performing amplitude-phase consistency calibration of the transmitting channels accordingly. The present invention can fit the relationship functions of the amplitude difference and phase difference between each transmitting channel and the reference transmitting channel changing with temperature in each temperature segmentation interval, improving the calibration accuracy in actual applications.

Description

Technical Field

[0001] The present invention relates to a digital phased array, and in particular to a method for calibrating the amplitude-phase consistency of the transmission channels of a digital phased array. Background Art

[0002] A digital phased array precisely controls the beam pointing and formation of an antenna in a digital manner. Compared with traditional phased array antennas, it has the advantages of small size and low cost. However, due to factors such as differences in device performance between array channels, differences in clock and synchronization signal transmission paths, actual position errors of array antenna elements, and mutual coupling effects between array antenna elements, there are inconsistencies in the initial phase and amplitude between array channels, which will cause distortion of the array beam pattern.

[0003] Therefore, it is necessary to calibrate the amplitude-phase consistency of the transmission channels of a digital phased array. However, most traditional calibration methods do not consider the influence of temperature. Although temperature compensation has been considered in recent years, it is generally through a look-up table method. The temperature information involved in the look-up table method is discrete. If it is between two discrete temperatures, compensation can often only be carried out by taking the temperature closest to it, which has a certain impact on the calibration accuracy. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for calibrating the amplitude-phase consistency of the transmission channels of a digital phased array, which can fit the relationship functions of the amplitude difference and phase difference between each transmission channel and the reference transmission channel with temperature change in each temperature segmentation interval, so that the amplitude difference and phase difference between each transmission channel and the reference transmission channel can be obtained according to the actual ambient temperature during application, improving the calibration accuracy.

[0005] The purpose of the present invention is achieved through the following technical solutions: A method for calibrating the amplitude-phase consistency of the transmission channels of a digital phased array includes:

[0006] S1. Generate a transmission calibration signal, and after passing through N transmission channels of the digital phased array respectively, detect the amplitude information and phase information of the output signals of each transmission channel;

[0007] S2. Select the first transmission channel of the digital phased array as the reference transmission channel, and calculate the amplitude difference and phase difference of the 2nd to Nth transmission channels relative to the reference transmission channel;

[0008] S3. In a given temperature range, gradually increase the temperature step by step at a fixed temperature step, and repeat steps S1 to S2 at each temperature. Then segment the temperature range to obtain multiple temperature segmentation intervals, and fit the relationship functions of the amplitude difference and phase difference between the 2nd to Nth transmission channels and the reference transmission channel with temperature change in each temperature segmentation interval;

[0009] S4. When transmitting through a digital phased array, according to the temperature segment interval where the actual temperature is located, obtain the relationship functions of the amplitude difference and phase difference between the 2nd to Nth transmitting channels and the reference channel changing with temperature, calculate the phase difference and amplitude difference of the 2nd to Nth transmitting channels relative to the reference channel, and perform amplitude-phase consistency calibration of the transmitting channels accordingly.

[0010] The beneficial effects of the present invention are as follows: The present invention takes into account the complexity of the amplitude difference and phase difference between each transmitting channel and the reference transmitting channel changing with temperature. If within a large temperature range, it is difficult to describe with a single function relationship. Therefore, the temperature range is segmented, and within each segment, the function relationship can be determined by fitting. Thus, the present invention fits the relationship functions of the amplitude difference and phase difference between each transmitting channel and the reference transmitting channel changing with temperature in each temperature segment interval, so that the amplitude difference and phase difference between each transmitting channel and the reference transmitting channel can be obtained according to the actual ambient temperature during application, improving the calibration accuracy. Description of the Drawings

[0011] Figure 1 It is a flowchart of the method of the present invention. Detailed Embodiment

[0012] The technical solution of the present invention will be further described in detail below with reference to the drawings, but the protection scope of the present invention is not limited to the following.

[0013] As Figure 1 shown, a method for calibrating the amplitude-phase consistency of the transmitting channels of a digital phased array includes:

[0014] S1. Generate a transmission calibration signal. After passing through the N transmitting channels of the digital phased array respectively, detect the amplitude information and phase information of the output signals of each transmitting channel.

[0015] The step S1 includes:

[0016] S101. Generate a transmission calibration signal and transmit it to each transmitting channel of the digital phased array; the digital phased array includes a total of N transmitting channels;

[0017] S102. After the transmission calibration signal passes through the transmitting channel, detect the output signals of each transmitting channel to obtain the amplitude and phase information of the output signals of each transmitting channel.

[0018] S2. Select the first transmitting channel of the digital phased array as the reference transmitting channel, and calculate the amplitude difference and phase difference of the 2nd to Nth transmitting channels relative to the reference transmitting channel.

[0019] The step S2 includes:

[0020] Let the amplitude information of the output signal of the reference transmission channel be A 1 , and the phase information be θ 1 ; the amplitude information of the output signals of the 2nd to Nth transmission channels is A 2 , A 3 ,..., A N , and the phase information of the output signals of the 2nd to Nth transmission channels is θ 2 , θ 3 ,..., θ N ;

[0021] The amplitude differences of the 2nd to Nth transmission channels relative to the reference transmission channel are respectively ΔA 2 , ΔA 3 ,..., ΔA N :

[0022] ΔA 2 = A 2 - A 1 ;

[0023] ΔA 3 = A 3 - A 1 ...

[0024] ΔA N = A N - A 1

[0025] The phase differences of the 2nd to Nth transmission channels relative to the reference transmission channel are respectively Δθ 2 , Δθ 3 ,..., Δθ N

[0026]

[0027] S3. In a given temperature range, gradually increase the temperature step by step at a fixed temperature step, and repeat steps S1 to S2 at each temperature. Then, segment the temperature range to obtain multiple temperature segment ranges, and fit the relationship functions of the amplitude differences and phase differences between the 2nd to Nth transmission channels and the reference transmission channel with respect to temperature in each temperature segment range;

[0028] The said step S3 includes:

[0029] S301. Let the given temperature range be [T MIN , T MAX , the fixed temperature step be ΔT, where T MAX - T MIN is an integer multiple of ΔT; in the embodiment of the present application, [T MIN,T MAX The range of [temperature] is -40°C to +60°C; in the embodiments of the present application, the temperature step ΔT is 0.1 or 0.2°C;

[0030] At an ambient temperature of T MIN ,T MIN +ΔT,T MIN +2ΔT,....,T MAX Steps S1 to S2 are repeatedly executed to obtain the amplitude difference and phase difference of the output signals of each emission channel relative to the output signal of the reference emission channel at each temperature; in the embodiments of the present application, the temperature adjustment method can be achieved by placing the test environment indoors and adjusting the indoor temperature.

[0031] S302. Uniformly segment the temperature range to obtain a plurality of temperature segmentation ranges, and each temperature segmentation range includes at least M ambient temperatures, where M is not less than 5; in the embodiments of the present application, the difference between the maximum temperature and the minimum temperature of each temperature range is 1°C.

[0032] S302. For any one temperature segmentation range, fit the relationship functions of the amplitude difference and phase difference between each emission channel and the reference channel changing with temperature:

[0033] (1) For the first emission channel, since the first emission channel is the reference channel, the amplitude difference and phase difference between it and the reference channel are both 0 and do not change with the ambient temperature;

[0034] (2) For any one of the second to Nth emission channels:

[0035] There are M ambient temperatures T1, T2,..., TM in the current temperature segmentation range, and the amplitude differences corresponding to the M ambient temperatures are denoted as ΔA T1 ,ΔA T2 ,...ΔA TM , where ΔA Tj represents the amplitude difference corresponding to the jth ambient temperature, and the phase differences corresponding to the M ambient temperatures are denoted as Δθ T1 ,Δθ T2 ,...Δθ TM , where Δθ Tj represents the phase difference corresponding to the jth ambient temperature, and j = 1, 2,..., M

[0036] Construct a quadratic polynomial regression model:

[0037] y = ax 2 + bx + c

[0038] where a, b, and c are model parameters to be solved, and x and y represent the independent variable and dependent variable of the model;

[0039] Using the set {T1, T2,..., TM} composed of M ambient temperatures as the set of independent variable values of the model, and the corresponding set of amplitude differences {ΔA T1 , ΔA T2 ,... ΔA TM} as the set of dependent variable values of the model, fitting the quadratic polynomial regression model, solving for the model parameters a, b, and c, and obtaining the relationship between the amplitude difference between the current transmission channel and the reference channel and temperature change;

[0040] Using the set {T1, T2,..., TM} composed of M ambient temperatures as the set of independent variable values of the model, and the corresponding set of phase differences {Δθ T1 , Δθ T2 ,... Δθ TM} as the set of dependent variable values of the model, fitting the quadratic polynomial regression model, solving for the parameters a, b, and c, and obtaining the relationship between the phase difference between the current transmission channel and the reference channel and temperature change;

[0041] (3) For each transmission channel among the 2nd to Nth transmission channels, repeat step (2) to obtain the relationship functions of the amplitude difference and phase difference between the 2nd to Nth transmission channels and the reference channel with respect to temperature change in the current temperature segmentation interval;

[0042] S303. For each temperature segmentation interval, repeat step S302 to obtain the relationship functions of the amplitude difference and phase difference between the 2nd to Nth transmission channels and the reference channel with respect to temperature change in each temperature segmentation interval.

[0043] S4. When transmitting through a digital phased array, according to the temperature segmentation interval where the actual temperature is located, obtain the relationship functions of the amplitude difference and phase difference between the 2nd to Nth transmission channels and the reference channel with respect to temperature change, calculate the phase difference and amplitude difference of the 2nd to Nth transmission channels relative to the reference channel, and perform amplitude-phase consistency calibration for the transmission channels accordingly.

[0044] The said step S4 includes:

[0045] S401. When transmitting through a digital phased array, measure the actual ambient temperature, judge the temperature segmentation interval where the actual ambient temperature is located, and then obtain the relationship functions of the amplitude difference and phase difference between each transmission channel among the 2nd to Nth transmission channels and the reference channel with respect to temperature change in this temperature segmentation interval;

[0046] S402. For each transmission channel among the 2nd to Nth transmission channels, substitute the actual ambient temperature into the relationship function of the amplitude difference between the transmission channel and the reference channel with respect to temperature change to obtain the amplitude difference between this transmission channel and the reference channel;

[0047] S403. For each of the second to Nth transmission channels, substitute the actual ambient temperature into the relationship function of the amplitude difference between the transmission channel and the reference channel varying with temperature, to obtain the amplitude difference between this transmission channel and the reference channel.

[0048] S404. When transmitting through a digital phased array, utilize the amplitude difference and phase difference between each of the second to Nth transmission channels and the reference channel to compensate the second to Nth transmission channels, so that their output signals maintain amplitude-phase consistency with the reference transmission channel.

[0049] In the embodiments of the present application, the amplitude and phase consistency here means that: the signal amplitudes and phases output by the second to Nth transmission channels are kept consistent with those of the first transmission channel. The calibration method can be achieved by adjusting the attenuators / amplifiers and phase shifters within the second to Nth transmission channels according to the calculated amplitude difference and phase difference; or by pre-adjusting the amplitudes and phases of the input signals of the second to Nth transmission channels according to the calculated amplitude difference and phase difference.

[0050] It should be noted that the calibration of the receiving channels can also be achieved by using the method of the present application. The calibration method is the same and will not be elaborated here.

[0051] The above is the preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in other combinations, modifications and environments, and can be changed within the scope of the concept described herein through the above teachings or the techniques or knowledge in related fields. And any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for calibrating amplitude and phase consistency of a transmitting channel of a digital phased array, characterized by: include: S1. Generate a transmit calibration signal, pass it through the N transmit channels of the digital phased array, and detect the amplitude and phase information of the output signal of each transmit channel; S2. Select the first transmission channel of the digital phased array as the reference transmission channel, and calculate the amplitude difference and phase difference of the second to Nth transmission channels relative to the reference transmission channel; S3. In a given temperature range, gradually increase the temperature according to a fixed temperature step, and repeat steps S1 to S2 at each temperature, then segment the temperature range to obtain multiple temperature segment ranges, and fit the relationship function of the amplitude difference and phase difference between the 2nd to Nth transmission channels and the reference transmission channel with the temperature in each temperature segment range; The step S3 comprises: S301. Assume that the given temperature range is [T MIN ,T MAX ], the fixed temperature step is ΔT, where T MAX -T MIN is an integer multiple of ΔT; At an ambient temperature of T MIN ,T MIN +ΔT,T MIN +2ΔT,....,T MAX When the temperature is 0, the steps S1 to S2 are repeated to obtain the amplitude difference and phase difference of the output signals of the second to Nth transmission channels relative to the output signal of the reference transmission channel at each temperature; S302. Evenly segment the temperature interval to obtain multiple temperature segment intervals, each temperature segment interval contains at least M ambient temperatures, M is not less than 5; S303. For any temperature segment interval, fit the relationship function between the amplitude difference and phase difference between each transmission channel and the reference channel as the temperature changes: (1) For the first transmitting channel, since the first transmitting channel is the reference channel, the amplitude and phase difference between it and the reference channel are both 0 and do not change with the ambient temperature; (2) For any transmission channel from the 2nd to the Nth transmission channel: There are M ambient temperatures T1, T2, ..., TM in the current temperature segment. The amplitude difference corresponding to the M ambient temperatures is recorded as ΔA. T1 ,ΔA T2 ,...ΔA TM , where ΔA Tj The amplitude difference corresponding to the jth ambient temperature is represented by Δθ, and the phase difference corresponding to the Mth ambient temperature is represented by Δθ T1 ,Δθ T2 ,...Δθ TM , where Δθ Tj represents the phase difference corresponding to the jth ambient temperature, j = 1, 2, ..., M Construct a quadratic polynomial regression model: y=ax 2 +bx+c Among them, a, b, c are model parameters, x, y represent the independent and dependent variables of the model; The set of M ambient temperatures {T1, T2, ..., TM} is used as the independent variable value set of the model, and the corresponding amplitude difference set {ΔA T1 ,ΔA T2 ,...ΔA TM } As the dependent variable value set of the model, the quadratic polynomial regression model is fitted to solve the model parameters a, b, c, and obtain the relationship between the amplitude difference between the current transmission channel and the reference channel and the temperature change; The set {T1, T2, ..., TM} consisting of M ambient temperatures is used as the set of independent variable values ​​of the model, and the corresponding phase differences constitute the set {Δθ T1 ,Δθ T2 ,...Δθ TM } As the dependent variable value set of the model, the quadratic polynomial regression model is fitted to solve the model parameters a, b, c, and obtain the relationship between the phase difference between the current transmission channel and the reference channel and the temperature change; (3) For each of the second to Nth transmission channels, repeat step (2) to obtain a function of the relationship between the amplitude difference and the phase difference between the second to Nth transmission channels and the reference channel and the temperature under the current temperature segmentation interval; S304. For each temperature segmentation interval, repeat step S303 to obtain a relationship function of the amplitude difference and phase difference between the 2nd to Nth transmission channels and the reference channel with temperature in each temperature segmentation interval; S4. When transmitting through the digital phased array, obtain the relationship function of the amplitude difference and phase difference between the 2nd to Nth transmission channels and the reference channel as the temperature changes according to the temperature segment range where the actual temperature is located, calculate the phase difference and amplitude difference of the 2nd to Nth transmission channels relative to the reference channel, and perform the amplitude and phase consistency calibration of the transmission channels based on this.

2. The method for calibrating amplitude and phase consistency of a transmitting channel of a digital phased array according to claim 1, characterized in that: The step S1 comprises: S101. Generate a transmit calibration signal and transmit it to each transmit channel of the digital phased array; the digital phased array comprises a total of N transmit channels; S102. After the transmission calibration signal passes through the transmission channel, the output signal of each transmission channel is detected to obtain the amplitude and phase information of the output signal of each transmission channel.

3. The method for calibrating amplitude and phase consistency of a transmitting channel of a digital phased array according to claim 1, characterized in that: The step S2 comprises: Assume that the amplitude information of the output signal of the reference transmission channel is A1, and the phase information is θ1; the amplitude information of the output signals of the 2nd to Nth transmission channels are A2, A3, ..., A N , the phase information of the output signals of the 2nd to Nth transmission channels is θ2,θ3,...,θ N ; The amplitude differences of the 2nd to Nth transmission channels relative to the reference transmission channel are ΔA2, ΔA3, ..., ΔA respectively. N : ΔA2=A2-A1; ΔA3=A3-A1, ... ΔA N =A N -A1 The phase differences of the 2nd to Nth transmission channels relative to the reference transmission channel are Δθ2, Δθ3, ..., Δθ N :

4. The method for calibrating amplitude and phase consistency of a transmitting channel of a digital phased array according to claim 1, characterized in that: The step S4 comprises: S401. When transmitting through a digital phased array, measure the actual ambient temperature, determine the temperature segmentation interval in which the actual ambient temperature is located, and then obtain the relationship function between the amplitude difference and phase difference between each of the 2nd to Nth transmitting channels and the reference channel in the temperature segmentation interval as the temperature changes; S402. For each of the 2nd to Nth transmitting channels, the actual ambient temperature is introduced into the relationship function between the amplitude difference between the transmitting channel and the reference channel and the temperature change, and the amplitude difference between the transmitting channel and the reference channel is obtained; S403. For each of the 2nd to Nth transmitting channels, the actual ambient temperature is introduced into the relationship function between the amplitude difference between the transmitting channel and the reference channel and the temperature change, and the amplitude difference between the transmitting channel and the reference channel is obtained; S404. When transmitting through the digital phased array, the amplitude difference and phase difference between each of the 2nd to Nth transmitting channels and the reference channel are used to compensate the 2nd to Nth transmitting channels so that their output signals maintain amplitude and phase consistency with the reference transmitting channel.

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