A digital phased array antenna noise power spectral density real-time monitoring method

Abstract

The present application relates to the field of phased array antenna, disclose a kind of digital phased array antenna noise power spectral density real-time monitoring method, based on Parseval theorem to time domain signal integration, then according to ADC peak voltage, quantization bit, impedance and signal bandwidth, noise power spectral density is calculated, and setting alarm threshold, achieve the purpose of low noise on-line real-time monitoring of digital phased array antenna.The present application first to a certain amount of continuous sampling time domain signal square sum is normalized, calculate noise energy statistics value;Second, according to ADC peak voltage, quantization bit, impedance and signal bandwidth, calculate noise power spectral density;Finally, set alarm threshold, when monitoring noise power spectral density is higher than the set threshold value, system sends alarm prompt.The present application is under the background of large-scale digital phased array antenna state management, effectively solve the real-time monitoring problem of noise power spectral density, can be applied to phased array antenna state monitoring and other fields.

Description

Technical Field

[0001] This invention relates to the field of phased array antennas, and in particular to a method for real-time monitoring of the noise power spectral density of a digital phased array antenna. Background Technology

[0002] Phased array antennas, with their flexible beam scanning capabilities, are widely used in communication, telemetry, and radar. The noise power spectral density (HPSD) of a phased array antenna is a crucial indicator of its performance; whether the HPSD is within acceptable limits directly impacts system performance. Therefore, monitoring the HPSD of a phased array antenna is essential.

[0003] Phased array antennas are generally classified into two categories: analog phased array antennas and digital phased array antennas. The noise power spectral density of analog phased array antennas can be monitored using instruments such as spectrum analyzers. Unlike traditional analog phased array antennas, digital phased array antennas perform analog-to-digital conversion (ADC) internally, offering advantages such as easy reconfiguration and expansion of digital beamforming. However, because the antenna components output digital signals, their noise power spectral density is no longer convenient to monitor directly using instruments like spectrum analyzers. One approach is to acquire the digital signals of the digital phased array antenna using a dedicated development tool and perform noise power spectral density analysis based on the Fourier transform method. However, this method requires a large amount of data, especially for large-scale phased array antennas with numerous channels, making online real-time monitoring inconvenient.

[0004] Therefore, a method for real-time monitoring of the noise power spectral density of digital phased array antennas is needed. Summary of the Invention

[0005] In view of this, in order to avoid the problems mentioned in the background art, the present invention discloses a method for real-time monitoring of the noise power spectral density of a digital phased array antenna.

[0006] The technical solution adopted in this invention is as follows:

[0007] A method for real-time monitoring of the noise power spectral density of a digital phased array antenna includes the following steps:

[0008] (1) Based on Passevar's theorem, the normalized sum of squares of multiple consecutively sampled time-domain signals is calculated to obtain the statistical value of noise energy;

[0009] (2) Calculate the noise voltage value corresponding to the noise energy statistics based on the ADC peak voltage and quantization bit depth;

[0010] (3) Calculate the noise power value based on the noise voltage value and impedance;

[0011] (4) Divide the noise power value by the signal bandwidth to calculate the noise power spectral density;

[0012] (5) Set alarm threshold. When the noise power spectral density is detected to be higher than the set threshold value, an alarm will be triggered.

[0013] Furthermore, the calculation method for the noise energy statistics in step (1) is as follows:

[0014]

[0015] In the formula, E n s(t) represents the noise energy statistics, t = 0, ..., N-1, and N is the number of consecutive sampling points.

[0016] Furthermore, the noise voltage value in step (2) is calculated as follows:

[0017]

[0018] In the formula, V n The noise voltage value, V pp Where is the peak voltage of the ADC, M is the quantization bit depth of the ADC, and E is the peak voltage of the ADC. n This represents the statistical value of noise energy.

[0019] Furthermore, the noise power value in step (3) is calculated as follows:

[0020]

[0021] In the formula, P n The noise power value is Ω, the impedance is V. n This is the noise voltage value.

[0022] The noise power spectral density in step (4) is calculated as follows:

[0023] N0 = 10log(P) n / B)+30

[0024] In the formula, N0 is the noise power spectral density, P n B is the noise power value, and B is the signal bandwidth.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] (i) The present invention proposes a method for real-time monitoring of noise power spectral density of digital phased array antennas, which has a small data transmission volume and is particularly convenient for online real-time monitoring of noise power spectral density of large-scale digital phased array antennas.

[0027] (ii) The present invention proposes a real-time monitoring method for the noise power spectral density of a digital phased array antenna. The display results are intuitive, close to the real noise power spectral density, and easy for operators to understand.

[0028] (iii) The present invention proposes a method for real-time monitoring of noise power spectral density of digital phased array antenna, which has an alarm prompt function. When the monitored noise power spectral density is higher than the set threshold value, the system can actively issue an alarm prompt. Attached Figure Description

[0029] Figure 1 This is a flowchart of the process of the present invention. Detailed Implementation

[0030] The present invention will be further described below with reference to specific implementation steps:

[0031] This invention provides a method for real-time monitoring of the noise power spectral density of a digital phased array antenna, referring to... Figure 1 The specific steps include:

[0032] ① Calculate the normalized sum of squares of N consecutively sampled time-domain signals s(t), and then calculate the noise energy statistical value E. n for

[0033]

[0034] In the formula, the number of sampling points N is 2048 for example.

[0035] ②Based on the ADC peak voltage V pp And the quantization bit depth M, calculate the noise energy statistics E. n The corresponding noise voltage value V n for

[0036]

[0037] In the formula, for example, V pp =1.75V, ADC quantization bit depth is 14 bits.

[0038] ③ Based on the noise voltage value V n Given the impedance Ω, calculate the noise power value P. n

[0039]

[0040] In the formula, the impedance Ω is 50 ohms for example.

[0041] ④ The noise power value P n Divide by the signal bandwidth B, and calculate the noise power spectral density N0 as follows:

[0042] N0 = 10log(P) n / B)+30

[0043] In the formula, the signal bandwidth B is 120MHz for example, and N0 is in dBm / Hz.

[0044] Furthermore, by integrating the formulas from steps ① to ④ and substituting the specific values ​​from the example, the expression for the noise power spectral density N0 is:

[0045] N0 = -141.1886 + 10log(E) n dBm / Hz

[0046] ⑤ Set an alarm threshold. When the noise power spectral density is detected to be higher than the set threshold value, the system will issue an alarm. For example, the alarm threshold value can be set to be 6dB higher than the average measured value of the noise power spectral density.

[0047] According to actual measurements, the noise energy statistics value E reported by the phased array antenna at a certain moment is... n =1020. If this value alone cannot intuitively represent the noise power spectral density of the phased array antenna, the system monitoring software converts the noise energy statistics into noise power spectral density using the formulas in steps ① to ④. The displayed result is N0 = -111.1025 dBm / Hz, which is intuitive and easy for operators to understand.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for real-time monitoring of noise power spectral density of a digital phased array antenna, characterized in that, Comprise the following steps: (1) Based on Parseval theorem, the normalized square sum of a plurality of continuous sampling time domain signals is calculated to obtain a noise energy statistical value; (2) According to the ADC peak voltage and the quantization bit number, the noise voltage value corresponding to the noise energy statistical value is calculated; (3) According to the noise voltage value and the impedance, the noise power value is calculated; (4) The noise power spectral density is calculated by dividing the noise power value by the signal bandwidth; (5) The alarm threshold is set, and when the monitored noise power spectral density is higher than the set threshold value, the alarm is given; Wherein, the calculation method of the noise voltage value in step (2) is: In the formula, is a noise voltage value, is an ADC peak voltage, is a quantization bit number of the ADC, is a noise energy statistical value; Wherein, the calculation method of the noise power value in step (3) is: wherein is a noise power value, is an impedance, is a noise voltage value; Wherein, the calculation method of the noise power spectral density in step (4) is: wherein is the noise power spectral density, is the noise power value, is the signal bandwidth.

2. The method of claim 1, wherein, The calculation method of the noise energy statistical value in step (1) is: In the formula, is a noise energy statistical value, is a time domain signal, , is the number of continuous sampling points.

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