A wet antenna attenuation evaluation method based on radome water film thickness model

Abstract

The present invention provides a wet antenna attenuation evaluation method based on a radome water film thickness model, comprising: obtaining structural parameters of a target radome; determining a pair of microwave signal transmitting devices and receiving devices under a preset frequency and a preset polarization mode to form a line-of-sight microwave link, and respectively equipping the target radome at the transmitting end and the receiving end of the line-of-sight microwave link; based on the line-of-sight microwave link, using a natural precipitation observation experiment to determine multiple groups of wet antenna attenuation and rain intensity samples; based on the wet antenna attenuation and rain intensity samples, optimizing and determining the radome water film thickness model according to a multi-layer medium transmission model; applying the radome water film thickness model to calculate the corresponding wet antenna attenuation value of the target radome at a preset rain intensity under any other microwave frequency and polarization mode. The present invention has the advantages of low cost, strong scalability, etc., and has extremely high practical application value.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communication system performance evaluation, and in particular to a wet antenna attenuation evaluation method based on a radome water film thickness model. Background Art

[0002] Wireless communication signals are often seriously affected by various meteorological elements in the atmosphere during propagation, among which precipitation is one of the important factors. Precipitation particles will cause scattering effects on electromagnetic waves, which will cause serious attenuation of communication signals along the path. There are existing models for the scattering attenuation of raindrops on the path that can be quantitatively described well. For example, the International Radio Union ITU-R P.838–3 recommendation gives an empirical power law relationship between rain-induced attenuation rate and rain intensity in the frequency range of 1 to 1000 GHz. In addition, under precipitation conditions, accumulated water will adhere to the antenna cover of the wireless communication system, causing additional wet antenna attenuation. Under certain conditions, the wet antenna attenuation value may even exceed the attenuation value caused by precipitation on the path. Therefore, effective evaluation of the wet antenna attenuation value is of great significance for the stable and efficient operation of wireless communication systems.

[0003] However, the quantitative evaluation of the wet antenna attenuation effect has not been widely studied so far. The main reason is that the wet antenna attenuation is not only related to the communication radome system, but also to factors such as the electromagnetic frequency and polarization mode of the communication signal. Some existing studies have statistically analyzed the wet antenna attenuation information based on individual observations of specific communication links and radome systems. Due to the diversity of communication system configurations, the wet antenna attenuation values ​​obtained from different studies often show great differences, and the statistical results are difficult to apply to the quantitative evaluation of wet antenna attenuation under other electromagnetic configurations. In fact, the essence of wet antenna attenuation is the additional attenuation of transmission caused by the attached water film on the radome. In theory, based on the known radome dielectric properties, the wet antenna attenuation value under any electromagnetic configuration can be calculated according to the water film thickness. Therefore, for a specific style of radome, by determining its radome water film thickness model, the wet antenna attenuation value of the communication system equipped with this style of radome can be effectively evaluated. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, an object of the present invention is to provide a wet antenna attenuation evaluation method based on a radome water film thickness model.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A wet antenna attenuation evaluation method based on a radome water film thickness model comprises:

[0007] Obtain the structural parameters of the target radome;

[0008] Determining a pair of microwave signal transmitting devices and receiving devices at a preset frequency and a preset polarization mode to form a line-of-sight microwave link, and equipping the transmitting end and the receiving end of the line-of-sight microwave link with target antenna covers respectively;

[0009] Based on the line-of-sight microwave link, multiple groups of wet antenna attenuation and rain intensity samples are determined using natural precipitation observation experiments;

[0010] Based on the wet antenna attenuation and the rain intensity sample, a radome water film thickness model is optimized and determined according to a multi-layer medium transmission model;

[0011] The radome water film thickness model is applied to calculate the wet antenna attenuation value corresponding to the target radome at a preset rain intensity under any other microwave frequency and polarization mode.

[0012] Preferably, the structural parameters include the number of structural layers M, the thickness of each layer medium D 1 ,D 2 ,…,D M And the complex refractive index n of each layer of medium 1 ,n 2 ,…,n M .

[0013] Preferably, based on the line-of-sight microwave link, multiple groups of wet antenna attenuation and rain intensity samples are determined by using natural precipitation observation experiments, including:

[0014] A rain intensity sensor is set in the middle of the line-of-sight microwave link to record the rain intensity R with a time resolution of T, and the corresponding theoretical rain attenuation value A is calculated according to the rain attenuation theoretical model. rain ;

[0015] Recording the transmission signal level TSL and the reception signal level RSL with a time resolution T, and calculating the attenuation value A of the line-of-sight microwave link; wherein A=TSL-RSL;

[0016] Extracting the attenuation baseline value Baseline of the line-of-sight microwave link;

[0017] Extract the wet antenna attenuation value WWA when it rains; where WWA = max(A-Baseline-A rain ,0).

[0018] Preferably, based on the wet antenna attenuation and the rain intensity sample, the radome water film thickness model is optimized and determined according to the multi-layer medium transmission model, including:

[0019] Calculate the theoretical transmittance T(f,P,D) of the target radome with M layers of dielectric under dry conditions 1 ,D 2 ,…,D M ,n1 ,n 2 ,…,n M ), f is the frequency, P is the polarization mode;

[0020] Calculate the theoretical transmittance T(f,P,D) of the target radome with M layers of dielectric under wet conditions 1 ,D 2 ,…,D M ,D water ,n 1 ,n 2 ,…,n M ,n water );n water is the complex refractive index of water; D water =αR β is the radome water film thickness model, α and β are empirical coefficients to be determined;

[0021] According to the wet antenna attenuation and rain intensity samples, combined with the optimization method, α = α 0 and β = β 0 ; The solution formula is: Among them, WWA i is the i-th wet antenna attenuation sample, α 0 and β 0 is the optimized value of the empirical coefficient of the radome water film thickness model, R i is the i-th rainfall intensity sample; f 0 and P 0 The frequency and polarization mode of a preset pair of microwave signal transmitting device and receiving device.

[0022] Preferably, the wet antenna attenuation value WWA corresponding to the target antenna cover at a preset rain intensity under any other microwave frequency and polarization mode is calculated. other The formula is:

[0023] f other is any microwave frequency, P other Any polarization mode.

[0024] Preferably, the target radome comprises a flat panel radome.

[0025] Preferably, the rainfall intensity sensor comprises a rain gauge.

[0026] Preferably, the rain attenuation theoretical model comprises an ITU-R rain attenuation model.

[0027] Preferably, the method for extracting the attenuation baseline value of the line-of-sight microwave link includes a dynamic baseline method.

[0028] Preferably, the multi-layer medium transmission model includes a Fresnel multi-layer medium propagation model.

[0029] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0030] The present invention provides a wet antenna attenuation evaluation method based on a radome water film thickness model, comprising: obtaining structural parameters of a target radome; determining a pair of microwave signal transmitting devices and receiving devices under a preset frequency and a preset polarization mode to form a line-of-sight microwave link, and equipping the target radome at the transmitting end and the receiving end of the line-of-sight microwave link respectively; based on the line-of-sight microwave link, determining multiple groups of wet antenna attenuation and rain intensity samples by using a natural precipitation observation experiment; based on the wet antenna attenuation and the rain intensity samples, determining a radome water film thickness model according to a multi-layer medium transmission model optimization; and applying the radome water film thickness model to calculate the wet antenna attenuation value corresponding to the target radome at a preset rain intensity under any other microwave frequency and polarization mode. Based on the microwave link precipitation observation test, the present invention establishes a wet antenna attenuation and rain intensity sample set, and optimizes the antenna cover water film thickness model parameters in combination with the multi-layer dielectric transmission model, thereby establishing the relationship between the fixed style antenna cover water film thickness and rain intensity; at the same time, the method only requires a single observation experiment to effectively evaluate the wet antenna attenuation value of any frequency and polarization wireless communication system under the same style antenna cover, which has the advantages of low cost and strong scalability, and has extremely high practical application value. The method can be applied to actual business as a new method for evaluating the wet antenna attenuation of wireless communication systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 A flow chart of a method provided by an embodiment of the present invention;

[0033] Figure 2 A flowchart of the embodiment of the present invention;

[0034] Figure 3 A schematic diagram of a precipitation observation experiment provided by an embodiment of the present invention;

[0035] Figure 4 The embodiment of the present invention provides other Schematic diagram of wet antenna attenuation results in the range of 10 to 100 GHz, vertical polarization, and rain intensity of 0 to 100 mm / h. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Figure 1 A flow chart of a method provided by an embodiment of the present invention, such as Figure 1 As shown, the present invention provides a wet antenna attenuation evaluation method based on a radome water film thickness model, comprising:

[0039] Step 100: Obtaining structural parameters of the target radome;

[0040] Step 200: determining a pair of microwave signal transmitting devices and receiving devices at a preset frequency and a preset polarization mode to form a line-of-sight microwave link, and equipping a target antenna cover at a transmitting end and a receiving end of the line-of-sight microwave link respectively;

[0041] Step 300: Based on the line-of-sight microwave link, a plurality of groups of wet antenna attenuation and rain intensity samples are determined by using a natural precipitation observation experiment;

[0042] Step 400: Based on the wet antenna attenuation and the rain intensity sample, determine the radome water film thickness model according to the multi-layer medium transmission model optimization;

[0043] Step 500: Apply the radome water film thickness model to calculate the wet antenna attenuation value corresponding to the target radome at a preset rain intensity under any other microwave frequency and polarization mode.

[0044] like Figure 2 As shown, the workflow of this embodiment includes the following steps:

[0045] (1) For a fixed-style radome (target radome), obtain the number of structural layers M and the dielectric thickness D of each layer. 1 , D 2 , …, D M (mm), the complex refractive index of each layer of medium n 1 , n 2 ,…,n M ;

[0046] (2) Figure 3 As shown, a fixed frequency f is selected 0 (GHz), polarization mode P0 A pair of microwave signal transmitting devices and receiving devices are provided under the antenna to form a line-of-sight microwave link with a distance of L (km), and fixed antenna covers are provided at the transmitting end and the receiving end respectively;

[0047] (3) Determine N groups of wet antenna attenuation and rainfall intensity samples through a natural precipitation observation experiment over a period of time, including executing steps (3-1) to (3-4):

[0048] (3-1) A rainfall intensity sensor is set in the middle of the link to record the rainfall intensity R (mm / h) with a time resolution of T (min) and calculate the corresponding theoretical rain attenuation value A according to the rain attenuation theoretical model. rain (dB);

[0049] (3-2) Record the transmission signal level TSL (dBm) and the reception signal level RSL (dBm) with a time resolution T (min), and calculate the link attenuation value A = TSL-RSL (dB);

[0050] (3-3) Extract the link attenuation baseline value Baseline (dB);

[0051] (3-4) Extract the wet antenna attenuation value WWA (dB) when it rains:

[0052] WWA=max(A-Baseline-A rain ,0)

[0053] (4) Optimizing and determining the radome water film thickness model according to the multi-layer medium transmission model, including executing steps (4-1) to (4-3):

[0054] (4-1) Calculate the theoretical transmittance T(f, P, D) of the M-layer dielectric fixed style radome under dry conditions 1 , D 2 , …, D M , n 1 , n 2 ,…,n M );

[0055] (4-2) Calculate the theoretical transmittance T(f, P, D) of the M-layer dielectric fixed style antenna cover under wet conditions 1 , D 2 , …, D M , D water , n 1 , n 2 ,…,n M , n water ), n water is the complex refractive index of water, D water =αR βis the radome water film thickness model, α and β are empirical coefficients to be determined;

[0056] (4-3) According to the wet antenna attenuation and rain intensity samples, combined with the optimization method, we can solve α = α 0 and β = β 0 :

[0057]

[0058] (5) The constant coefficient radome water film thickness model is applied to calculate the fixed style radome system at any other microwave frequency f other (GHz), polarization mode P other The corresponding wet antenna attenuation value when the rain intensity is R is:

[0059]

[0060] Furthermore, the fixed-style radome includes but is not limited to a flat-panel radome.

[0061] Furthermore, the rainfall intensity sensor includes but is not limited to a rain gauge.

[0062] Furthermore, the theoretical rain-induced attenuation calculation model includes but is not limited to the ITU-R rain attenuation model.

[0063] Furthermore, the link attenuation baseline extraction method includes but is not limited to a dynamic baseline method.

[0064] Furthermore, the multi-layer medium transmission model includes but is not limited to the Fresnel multi-layer medium propagation model.

[0065] Furthermore, the optimization method includes but is not limited to the least squares method.

[0066] Specifically, the present invention uses a microwave link precipitation observation test configured with a fixed style radome to obtain a wet antenna attenuation and rain intensity sample set, uses a multi-layer dielectric transmission model to calculate the theoretical wet antenna attenuation, and optimizes and solves the radome water film thickness model on this basis, thereby realizing an effective evaluation of the wet antenna attenuation of a wireless communication system with any frequency and polarization under the same style radome configuration, which mainly includes the following steps:

[0067] 1. For fixed style radome, it is made of single layer fiberglass material with thickness D 1 =1mm, medium complex refractive index n 1 =1.96-0.020i;

[0068] 2. Select a pair of microwave signal transmitters and receivers with a frequency of 26 GHz and vertical polarization to form a line-of-sight microwave link with a distance of L = 1 km, and equip the transmitter and receiver with fixed antenna covers respectively;

[0069] 3. Determine 1000 sets of wet antenna attenuation and rainfall intensity samples through a period of natural precipitation observation experiments:

[0070] (1) A rain gauge is set in the middle of the link to record the rainfall intensity R (mm / h) with a time resolution of T = 1 min, and the corresponding theoretical rain attenuation value A is calculated according to the ITU-R rain attenuation theoretical model. rain =aR b L (dB), where a = 0.17, b = 0.94;

[0071] (2) Record the transmit signal level TSL (dBm) and the receive signal level RSL (dBm) with a time resolution of T = 1 min, and calculate the link attenuation value A = TSL-RSL (dB);

[0072] (3) Extract the attenuation baseline value of the link at the tminth time using the dynamic baseline method:

[0073] Baseline(t)=max{A(t-30),A(t-29),...,A(t-1)};

[0074] (4) Extract the wet antenna attenuation value WWA (dB) when it rains:

[0075] WWA=max(A-Baseline-A rain ,0);

[0076] 4. According to the Fresnel multi-layer medium propagation model, optimize and determine the radome water film thickness model:

[0077] (1) Calculate the theoretical transmittance T of a single-layer dielectric fixed-type radome under dry conditions (f = 26 GHz, P = vertical polarization, D 1 =1mm, n 1 =1.96-0.020i);

[0078] (2) Calculation of the theoretical transmittance T (f = 26 GHz, P = vertical polarization, D) of a single-layer dielectric fixed-type radome under wet conditions 1 =1mm, D water , n 1 =1.96-0.020i,n water =9.05-0.029i), D water =aR b is the radome water film thickness model, a and b are undetermined empirical coefficients;

[0079] (3) According to the wet antenna attenuation and rain intensity samples, combined with the least squares method, we can solve α = 0.02 and β = 0.24:

[0080]

[0081] 5. Apply the constant coefficient radome water film thickness model to calculate the fixed style radome system at any other microwave frequency f other (GHz), polarization mode P other The corresponding wet antenna attenuation value when the rain intensity is R is:

[0082]

[0083] When f other The results of wet antenna attenuation values ​​in the range of 10 to 100 GHz, vertical polarization, and rain intensity of 0 to 100 mm / h are shown as follows: Figure 4 shown.

[0084] The beneficial effects of the present invention are as follows:

[0085] The present invention proposes a radome water film thickness model and a wet antenna attenuation assessment method. Based on the microwave link precipitation observation test, a wet antenna attenuation and rain intensity sample set is established. At the same time, the radome water film thickness model parameters are optimized in combination with the multi-layer dielectric transmission model, and the relationship between the water film thickness and rain intensity of a fixed-style radome is established. At the same time, this method only requires a single observation experiment to effectively assess the wet antenna attenuation value of any frequency and polarization wireless communication system under the same style radome. It has the advantages of low cost and strong scalability, and has extremely high practical application value. This method can be applied to actual business as a new method for wet antenna attenuation assessment of wireless communication systems.

[0086] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0087] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A wet antenna attenuation evaluation method based on a radome water film thickness model, characterized in that: include: Obtain the structural parameters of the target radome; Determining a pair of microwave signal transmitting devices and receiving devices at a preset frequency and a preset polarization mode to form a line-of-sight microwave link, and equipping the transmitting end and the receiving end of the line-of-sight microwave link with target antenna covers respectively; Based on the line-of-sight microwave link, multiple groups of wet antenna attenuation and rain intensity samples are determined using natural precipitation observation experiments; Based on the wet antenna attenuation and the rain intensity sample, a radome water film thickness model is optimized and determined according to a multi-layer medium transmission model; The radome water film thickness model is applied to calculate the wet antenna attenuation value corresponding to the target radome at a preset rain intensity under any other microwave frequency and polarization mode; The structural parameters include the number of structural layers M , the thickness of each dielectric layer D 1, D 2,…, D M And the complex refractive index of each layer of medium n 1, n 2,…, n M ; Based on the line-of-sight microwave link, multiple groups of wet antenna attenuation and rain intensity samples are determined using natural precipitation observation experiments, including: A rainfall intensity sensor is set in the middle of the line-of-sight microwave link, with a recording time resolution of T Rainfall R , and calculate the corresponding theoretical rain attenuation value according to the rain attenuation theoretical model A rain ; With time resolution T Recording the transmit signal level TSL and received signal level RSL , and calculate the attenuation value of the line-of-sight microwave link A ;in, A = TSL - RSL ; Extract the attenuation baseline value of the line-of-sight microwave link Baseline ; Extract the wet antenna attenuation value when it rains WWA ;in, ; Based on the wet antenna attenuation and the rain intensity sample, a radome water film thickness model is optimized and determined according to a multi-layer medium transmission model, including: Calculation under dry conditions M Theoretical transmittance of target radome with layer dielectric T ( f , P , D 1, D 2,…, D M , n 1, n 2,…, n M ); f is the frequency, P is the polarization mode; Calculation under wet conditions M Theoretical transmittance of target radome with layer dielectric T ( f , P , D 1, D 2,…, D M , D water , n 1, n 2,…, n M , n water ); n water is the complex refractive index of water; D water = αR β is the radome water film thickness model, α and β is the undetermined empirical coefficient; Based on the wet antenna attenuation and rain intensity samples, combined with the optimization method, we can solve ; The solution formula is: ; in, WWA i For the i wet antenna attenuation samples, α 0 and β 0 is the optimized value of the empirical coefficient of the radome water film thickness model, R i For the i Rainfall intensity samples; f 0 and P 0 The frequency and polarization mode of a preset pair of microwave signal transmitting device and receiving device; Calculate the wet antenna attenuation value corresponding to the target antenna cover at a preset rain intensity under any other microwave frequency and polarization mode WWA other The formula is: ; f other For any microwave frequency, P other Any polarization mode.

2. The wet antenna attenuation evaluation method based on the radome water film thickness model according to claim 1 is characterized in that: The target radome includes a flat panel radome.

3. The wet antenna attenuation evaluation method based on the radome water film thickness model according to claim 1 is characterized in that: The rain intensity sensor comprises a rain gauge.

4. The wet antenna attenuation evaluation method based on the radome water film thickness model according to claim 1 is characterized in that: The rain attenuation theoretical model includes the ITU-R rain attenuation model.

5. The wet antenna attenuation evaluation method based on the radome water film thickness model according to claim 1 is characterized in that: The method for extracting the attenuation baseline value of the line-of-sight microwave link includes a dynamic baseline method.

6. The wet antenna attenuation evaluation method based on the radome water film thickness model according to claim 1 is characterized in that: The multi-layer medium transmission model includes a Fresnel multi-layer medium propagation model.

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