阅读说明：本技术 一种减小暗室反射性能测量误差的方法 (Method for reducing measurement error of reflection performance of darkroom ) 是由 康宁 付子豪 黄承祖 彭博 成永杰 代明珍 崔腾林 赵鹏 于 2020-12-09 设计创作，主要内容包括：本发明公开一种减小暗室反射性能测量误差的方法,包括：提供一被测暗室,在所述被测暗室内设置天线支架台,将发射天线与接收天线置于所述天线支架台上,保持收发天线及天线支架台相对位置固定；将所述天线支架台正对暗室墙面进行测量,获取被测暗室墙面的第一反射信号；在被测暗室墙面位置处放置参考金属板,将所述天线支架台正对暗室墙面进行测量,获取参考金属板的第一反射信号；将所述天线支架台背对暗室墙面进行测量,获取被测暗室墙面的第二反射信号；在被测暗室墙面位置处放置参考金属板,将所述天线支架台背对暗室墙面进行测量,获取参考金属板的第二反射信号；计算得到被测暗室墙面反射性能。本发明的优点是：实现简单,减小测量误差。(The invention discloses a method for reducing the measurement error of the reflection performance of a darkroom, which comprises the following steps: providing a tested darkroom, arranging an antenna support stand in the tested darkroom, placing a transmitting antenna and a receiving antenna on the antenna support stand, and keeping the relative positions of the transmitting antenna and the receiving antenna and the antenna support stand fixed; the antenna support platform is directly opposite to the wall surface of the darkroom to be measured, and a first reflection signal of the wall surface of the darkroom to be measured is obtained; placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the antenna support stand right opposite to the wall surface of the darkroom to obtain a first reflection signal of the reference metal plate; measuring the wall surface of the darkroom by the back of the antenna bracket to obtain a second reflected signal of the wall surface of the darkroom to be measured; placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the back of the antenna bracket to the wall surface of the darkroom to obtain a second reflected signal of the reference metal plate; and calculating to obtain the reflection performance of the wall surface of the tested darkroom. The invention has the advantages that: the method is simple to implement and reduces measurement errors.)

1. A method of reducing darkroom reflectance measurement errors, comprising:

providing a tested darkroom, arranging an antenna support stand in the tested darkroom, placing a transmitting antenna and a receiving antenna on the antenna support stand, and keeping the relative positions of the transmitting antenna and the receiving antenna and the antenna support stand fixed;

the antenna support platform is directly opposite to the wall surface of the darkroom to be measured, and a first reflection signal of the wall surface of the darkroom to be measured is obtained;

placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the antenna support stand right opposite to the wall surface of the darkroom to obtain a first reflection signal of the reference metal plate;

measuring the wall surface of the darkroom by the back of the antenna bracket to obtain a second reflected signal of the wall surface of the darkroom to be measured;

placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the back of the antenna bracket to the wall surface of the darkroom to obtain a second reflected signal of the reference metal plate;

and calculating the reflection performance of the wall surface of the tested darkroom according to the correlation among the first reflection signal of the wall surface of the tested darkroom, the first reflection signal of the reference metal plate, the second reflection signal of the wall surface of the tested darkroom and the second reflection signal of the reference metal plate.

2. The method of reducing darkroom reflectance measurement errors in accordance with claim 1, wherein: will antenna support platform just measures darkroom wall, includes: the antenna support stand is directly opposite to the wall surface of a darkroom for measurement, a signal generator generates a signal, the signal is radiated to the space through a transmitting antenna, and the signal is received by a receiving antenna.

3. The method of reducing darkroom reflectance measurement errors in accordance with claim 2, wherein: place reference metal sheet in surveyed darkroom wall position department, will antenna support platform just measures the darkroom wall, includes: the relative positions of the transmitting and receiving antenna and the antenna support stand are kept fixed.

4. The method of reducing darkroom reflectance measurement errors in accordance with claim 1, wherein: will antenna boom bench back of the body is measured darkroom wall, includes: and rotating the whole antenna support platform by 180 degrees along the horizontal direction to enable the transmitting and receiving antenna to face back to the wall surface of the darkroom to be detected and face the space of the darkroom.

5. The method of reducing darkroom reflectance measurement errors in accordance with claim 4, wherein: place reference metal sheet in surveyed darkroom wall position department, will antenna boom bench back of the body measures the darkroom wall, includes: the relative positions of the transmitting and receiving antenna and the antenna support stand are kept fixed.

6. The method of reducing darkroom reflectance measurement errors in accordance with claim 1, wherein: the reflection performance of the wall surface of the darkroom to be measured is calculated according to the following algorithm:

wherein S is₁Is the first reflected signal of the wall surface of the darkroom to be measured, M₁Is a first reflected signal of the reference metal plate, S₂For the second reflected signal of the wall of the darkroom to be measured, M₂Is the second reflected signal of the reference metal plate.

Technical Field

The invention belongs to the technical field of communication, and particularly relates to a method for reducing reflection performance measurement errors of a darkroom.

Background

The anechoic chamber is built by coating wave-absorbing materials on the inner surface of a metal shielding shell, the coated wave-absorbing materials are mainly used for absorbing electromagnetic waves irradiated on the surface of the metal shielding shell and reducing reflection signals, and the performance of different wave-absorbing materials is generally expressed by adopting reflectivity due to different absorption and reflection capacities of the different wave-absorbing materials on the electromagnetic waves. Because the reflection performance of the wall surface of the darkroom is mainly determined by the performance of the wave-absorbing material, the reflection performance of the darkroom is generally represented by the reflection performance of the wave-absorbing darkroom of the darkroom. The general method for measuring the reflection performance of the wave-absorbing darkroom is a transmitting-receiving antenna irradiation method, and the principle of the method is that the reflection performance of the wave-absorbing darkroom is calculated by comparing a reflection signal of a measured wave-absorbing material with a reflection signal of a reference metal plate and utilizing two reflection signals obtained by two times of measurement.

A method for measuring reflection performance of a reference wave-absorbing darkroom for measuring reflection performance of a darkroom wall surface comprises the steps of measuring the reflection performance of the darkroom twice according to the principle of a measuring method, wherein one time is a signal of electromagnetic waves reflected by the wall surface of the darkroom to be measured, the other time is a signal of the electromagnetic waves reflected by a reference metal plate, firstly, a receiving and transmitting antenna is aligned to the wall surface of the darkroom to be measured, the signal generated by a signal generator radiates the electromagnetic waves to the space through a transmitting antenna, and a receiving antenna receives the electromagnetic waves reflected by the wall surface of the darkroom to be measured and sends the electromagnetic waves to a signal receiving device; and (4) placing a reference metal plate at the wall surface position of the darkroom to be measured, and repeating the measuring steps. In order to calculate the reflection performance of the wall surface of the measured darkroom, a reflected signal of the wall surface of the measured darkroom and a reflected signal of the reference metal plate need to be obtained.

Analyzing the above-mentioned measuring method, in the measuring process, the signal sent into the signal receiving device by the receiving antenna includes three parts: a transmitting antenna directly coupled to a signal of a receiving antenna; the transmitting antenna radiates to the wall surface of the tested darkroom or the reference metal plate, and the signal of the receiving antenna is reflected by the wall surface of the tested darkroom or the reference metal plate; and measuring stray signals generated by other reflectors in the space, wherein the second part, the measured darkroom wall surface or the reference metal plate reflected signal is a signal required for calculating the reflection performance of the darkroom, and therefore the signal of the second part needs to be separated. A common signal processing method is to convert a frequency domain signal into a time domain, separate three signals from time according to different times of the time domain signal, and then convert the time domain signal into the frequency domain again to obtain a measurement result. Firstly, in the process of converting a frequency domain signal into a time domain and then converting the frequency domain signal into the frequency domain, data truncation exists, and truncation errors can be introduced into a measurement result; secondly, when signals are separated in time, different positions of a time window can cause difference of measurement results; in addition, because the coupling path of the transmitting and receiving antenna is closer, compared with the reflected signal, the amplitude of the direct coupling signal of the transmitting and receiving antenna is equivalent to or larger than that of the reflected signal, and the smaller reflected signal is completely separated from the larger direct coupling signal, which is difficult to realize; meanwhile, due to the existence of the antenna measuring bracket and the space reflector, the space stray signal is difficult to completely eliminate, and the amplitude of the space stray signal is small, so that the space stray signal is easy to mix into a wall surface reflection signal or a reference metal plate reflection signal of a tested darkroom. In the existing darkroom reflection performance measuring method, two antennas are respectively adopted as a transmitting antenna and a receiving antenna, wherein the transmitting antenna is connected with a signal generator, the receiving antenna is connected with receiving equipment, reflection signals of a darkroom wall surface and a reference metal plate are respectively obtained by measuring the darkroom wall surface and the reference metal plate twice, and the darkroom wall surface reflection performance is obtained by calculation. The existing measuring method is easy to introduce larger measuring errors, so that the measuring result of the reflection performance of a darkroom is influenced.

Disclosure of Invention

The invention aims to provide a method for reducing the measurement error of the reflection performance of a darkroom, and solves the problems of how to improve the measurement accuracy of the reflection performance of the darkroom and reduce the measurement error.

In view of the above, the present invention provides a method for reducing measurement error of reflection performance of a darkroom, comprising:

providing a tested darkroom, arranging an antenna support stand in the tested darkroom, placing a transmitting antenna and a receiving antenna on the antenna support stand, and keeping the relative positions of the transmitting antenna and the receiving antenna and the antenna support stand fixed;

the antenna support platform is directly opposite to the wall surface of the darkroom to be measured, and a first reflection signal of the wall surface of the darkroom to be measured is obtained;

placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the antenna support stand right opposite to the wall surface of the darkroom to obtain a first reflection signal of the reference metal plate;

measuring the wall surface of the darkroom by the back of the antenna bracket to obtain a second reflected signal of the wall surface of the darkroom to be measured;

placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the back of the antenna bracket to the wall surface of the darkroom to obtain a second reflected signal of the reference metal plate;

and calculating the reflection performance of the wall surface of the tested darkroom according to the correlation among the first reflection signal of the wall surface of the tested darkroom, the first reflection signal of the reference metal plate, the second reflection signal of the wall surface of the tested darkroom and the second reflection signal of the reference metal plate.

Further, with the antenna support platform just to measuring darkroom wall, include: the antenna support stand is directly opposite to the wall surface of a darkroom for measurement, a signal generator generates a signal, the signal is radiated to the space through a transmitting antenna, and the signal is received by a receiving antenna.

Further, place the reference metal sheet in surveyed darkroom wall position department, will antenna support platform just measures the darkroom wall, includes: the relative positions of the transmitting and receiving antenna and the antenna support stand are kept fixed.

Further, will antenna boom bench back of the body is measured darkroom wall, includes: and rotating the whole antenna support platform by 180 degrees along the horizontal direction to enable the transmitting and receiving antenna to face back to the wall surface of the darkroom to be detected and face the space of the darkroom.

Further, place the reference metal sheet in surveyed darkroom wall position department, will antenna boom bench back of the body measures the darkroom wall, includes: the relative positions of the transmitting and receiving antenna and the antenna support stand are kept fixed.

Further, the reflection performance of the wall surface of the tested darkroom is calculated according to the following algorithm:

wherein S is₁Is the first reflected signal of the wall surface of the darkroom to be measured, M₁Is a first reflected signal of the reference metal plate, S₂For the second reflected signal of the wall of the darkroom to be measured, M₂Is the second reflected signal of the reference metal plate.

The invention achieves the following significant beneficial effects:

the realization is simple, include: providing a tested darkroom, arranging an antenna support stand in the tested darkroom, placing a transmitting antenna and a receiving antenna on the antenna support stand, and keeping the relative positions of the transmitting antenna and the receiving antenna and the antenna support stand fixed; the antenna support platform is directly opposite to the wall surface of the darkroom to be measured, and a first reflection signal of the wall surface of the darkroom to be measured is obtained; placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the antenna support stand right opposite to the wall surface of the darkroom to obtain a first reflection signal of the reference metal plate; measuring the wall surface of the darkroom by the back of the antenna bracket to obtain a second reflected signal of the wall surface of the darkroom to be measured; placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the back of the antenna bracket to the wall surface of the darkroom to obtain a second reflected signal of the reference metal plate; and calculating the reflection performance of the wall surface of the tested darkroom according to the correlation among the first reflection signal of the wall surface of the tested darkroom, the first reflection signal of the reference metal plate, the second reflection signal of the wall surface of the tested darkroom and the second reflection signal of the reference metal plate. The reflection performance of the wall surface of the tested darkroom is calculated by changing the measurement direction and selecting a reasonable measurement method while the wall surface of the darkroom or the reference metal plate reflection signal does not need to be separated. By using the method, the truncation error in the signal time-frequency domain conversion process can be reduced, the influence of the direct coupling signal of the receiving and transmitting antenna and the space stray signal on the reflection signal can be effectively reduced, the measurement accuracy of the reflection performance of the darkroom is improved, and the measurement error is reduced.

Drawings

FIG. 1 is a flow chart of a method of reducing darkroom reflectance measurement errors in accordance with the present invention;

FIG. 2 is a schematic diagram of the measurement of the wall reflection signal of the darkroom under test according to the present invention;

FIG. 3 is a schematic diagram of the present invention showing the measurement of the reflected signal of the reference metal plate;

FIG. 4 is a schematic diagram of back-to-back measurement of the reflection signal of the wall of the darkroom under test according to the present invention;

FIG. 5 is a schematic diagram of back-to-back measurement of a reference metal plate reflection signal according to the present invention.

Detailed Description

The advantages and features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings and detailed description of specific embodiments of the invention. It is to be noted that the drawings are in a very simplified form and are not to scale, which is intended merely for convenience and clarity in describing embodiments of the invention.

It should be noted that, for clarity of description of the present invention, various embodiments are specifically described to further illustrate different implementations of the present invention, wherein the embodiments are illustrative and not exhaustive. In addition, for simplicity of description, the contents mentioned in the previous embodiments are often omitted in the following embodiments, and therefore, the contents not mentioned in the following embodiments may be referred to the previous embodiments accordingly.

While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood that the inventors do not intend to limit the invention to the particular embodiments described, but intend to protect all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims. The same meta-module part number may be used throughout the drawings to represent the same or similar parts.

Referring to fig. 1 to 5, the present invention provides a method for reducing measurement errors of reflection performance of a darkroom, comprising:

step S101, providing a darkroom to be tested, arranging an antenna support stand in the darkroom to be tested, placing a transmitting antenna and a receiving antenna on the antenna support stand, and keeping the relative positions of the transmitting antenna, the receiving antenna and the antenna support stand fixed;

step S102, the antenna support platform is measured right opposite to the wall surface of the darkroom, and a first reflection signal of the wall surface of the darkroom to be measured is obtained;

step S103, placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the antenna support stand right against the wall surface of the darkroom to obtain a first reflection signal of the reference metal plate;

step S104, measuring the wall surface of the darkroom by the back of the antenna bracket to obtain a second reflected signal of the wall surface of the darkroom to be measured;

s105, placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the back of the antenna bracket to the wall surface of the darkroom to obtain a second reflection signal of the reference metal plate;

and step S106, calculating the reflection performance of the wall surface of the tested darkroom according to the correlation among the first reflection signal of the wall surface of the tested darkroom, the first reflection signal of the reference metal plate, the second reflection signal of the wall surface of the tested darkroom and the second reflection signal of the reference metal plate.

In one embodiment, measuring the antenna mount table against a wall of a darkroom includes: the antenna support stand is directly opposite to the wall surface of a darkroom for measurement, a signal generator generates a signal, the signal is radiated to the space through a transmitting antenna, and the signal is received by a receiving antenna.

In one embodiment, placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the antenna support stand against the wall surface of the darkroom comprises the following steps: the relative positions of the transmitting and receiving antenna and the antenna support stand are kept fixed.

In one embodiment, measuring the antenna mount table against a wall of a darkroom includes: and rotating the whole antenna support platform by 180 degrees along the horizontal direction to enable the transmitting and receiving antenna to face back to the wall surface of the darkroom to be detected and face the space of the darkroom.

In one embodiment, placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the antenna bracket table back to the wall surface of the darkroom comprises the following steps: the relative positions of the transmitting and receiving antenna and the antenna support stand are kept fixed.

In one embodiment, the measured darkroom wall reflection performance is calculated according to the following algorithm:

wherein S is₁Is the first reflected signal of the wall surface of the darkroom to be measured, M₁Is a first reflected signal of the reference metal plate, S₂For the second reflected signal of the wall of the darkroom to be measured, M₂Is the second reflected signal of the reference metal plate.

As a specific example, the darkroom reflection performance measurement of the present invention uses the measurement method shown in fig. 2, fig. 3, fig. 4 and fig. 5, in which a measurement system composed of a signal generator, a signal receiving device, a transmitting antenna, a receiving antenna and an antenna support stand is used, and the measurement of the darkroom reflection performance can be realized by the system.

As a specific embodiment, as shown in fig. 3, firstly, the transmitting and receiving antenna is directed to the wall surface of the darkroom to be measured, the distance is measured as d, the signal generated by the signal generator radiates electromagnetic waves to the space through the transmitting antenna, the receiving antenna receives the electromagnetic waves reflected by the wall surface of the darkroom to be measured, and the electromagnetic waves are sent to the signal receiving device; as shown in FIG. 3, a reference metal plate is placed on the wall surface of the darkroom to be measured, and the above measurement steps are repeated. According to the calculation formula (1), in order to calculate the reflection performance of the darkroom, a wall surface reflection signal of the darkroom to be measured and a reference metal plate reflection signal need to be obtained.

As a specific example, in the measurement process shown in fig. 2, the signal sent from the receiving antenna to the signal receiving device is denoted as S₁The method comprises the following three parts: transmitting antenna directly coupled to groundReceiving the signal of the antenna, denoted S_oh1(ii) a The transmitting antenna radiates to the wall surface of the tested darkroom, and the signal reflected to the receiving antenna by the wall surface of the tested darkroom is recorded as S_fs1(ii) a Measuring stray signals produced by other reflectors in the space, and recording the stray signals as S_zs1. Wherein, the second part is the reflection signal S of the wall surface of the darkroom to be detected_fs1Is the signal required to calculate the reflection performance of the darkroom. The relationship between the signals of each part is as follows:

S₁＝S_oh1+S_fs1+S_zs1………………………………………(2)

as a specific example, in the measurement process shown in fig. 3, the signal sent from the receiving antenna to the signal receiving device is denoted as M₁The method comprises the following three parts: signals from transmitting antennas directly coupled to receiving antennas, denoted M_oh1(ii) a The signal radiated by the transmitting antenna to the reference metal plate and reflected by the reference metal plate to the receiving antenna is denoted as M_fs1(ii) a The stray signal produced by the rest of the reflectors in the measurement space is recorded as M_zs1. Wherein the second part, the reference metal plate, reflects the signal M_fs1Is the signal required to calculate the reflection performance of the darkroom. The relationship between the signals of each part is as follows:

M₁＝M_oh1+M_fs1+M_zs1………………………………………(3)

as a specific example, according to the measurement processes shown in fig. 2 and 3 and the method for measuring the reflection performance of the wall surface of the darkroom to be measured, the calculation formula of the reflection performance is as follows:

as a specific embodiment, after the measurement process shown in fig. 2 and 3 is completed, the relative position between the transceiving antenna and the antenna support stand is kept unchanged, the transceiving antenna and the antenna support stand are integrally rotated 180 degrees along the horizontal direction, and the rest of the measurement arrangements are kept unchanged, at this time, the transceiving antenna faces away from the wall surface of the darkroom to be measured and faces the darkroom space. As shown in fig. 4 and 5, the above measurement process is repeated,the signals received by the receiving antenna in the two measurements are obtained. Wherein during the measurement process shown in fig. 5, the signal sent from the receiving antenna to the signal receiving device is denoted as S₂(ii) a Because the receiving and transmitting antenna used in the darkroom reflection performance measurement has good directivity, when the receiving and transmitting antenna is opposite to the wall surface of the darkroom to be measured and is opposite to the darkroom space, the transmitting antenna radiates to the darkroom space, and the signal reflected to the receiving antenna through the darkroom space is longer in transmission path and larger in signal attenuation compared with other reflected signals, and the amplitude of the signal is small enough to be ignored, so that S₂The device mainly comprises two parts: signals, denoted S, with transmitting antennas directly coupled to receiving antennas_oh2(ii) a Measuring stray signals produced by other reflectors in the space, and recording the stray signals as S_zs2. The relationship between the signals of each part is as follows:

S₂＝S_oh2+S_zs2………………………………………(5)

as a specific example, in the measurement process shown in fig. 5, since the transmitting/receiving antenna faces away from the reference metal plate and faces the darkroom space, the signal sent into the signal receiving device by the receiving antenna is denoted as M₂The method comprises two parts: signals from transmitting antennas directly coupled to receiving antennas, denoted M_oh2(ii) a The stray signal produced by the rest of the reflectors in the measurement space is recorded as M_zs2. The relationship between the signals of each part is as follows:

M₂＝M_oh2+M_zs2………………………………………(6)

as a specific example, in the received signals obtained by the measurements in fig. 2 and 4, since the relative positions of the transmitting antenna and the receiving antenna are kept unchanged, the directly coupled signals of the transceiving antenna are kept unchanged in the two measurements; meanwhile, except that the receiving and transmitting antenna and the antenna support table change 180 degrees along the horizontal direction, the arrangement of the rest is unchanged, so that the spatial stray signals in the two measurement processes are basically kept unchanged; similarly, in the received signals obtained by the measurements of fig. 3 and 5, since the relative positions of the transmitting antenna and the receiving antenna are kept unchanged, the signals directly coupled by the transmitting and receiving antennas are kept unchanged in the two measurements; meanwhile, except that the transmitting and receiving antenna and the antenna support table change 180 degrees along the horizontal direction, the arrangement of the rest is unchanged, so that the spatial stray signals are basically kept unchanged in the two measurement processes. Therefore, in the above measurement process, the following relationship exists between the received signals:

S_oh1＝S_oh2………………………………………(7)

S_zs1＝S_zs2………………………………………(8)

M_oh1＝M_oh2………………………………………(9)

M_zs1＝M_zs2………………………………………(10)

from equations (2), (5), (7) and (8), it is possible to obtain:

S_fs1＝S₁-S₂………………………………………(11)

from equations (3), (6), (9) and (10), it is possible to obtain:

M_fs1＝M₁-M₂………………………………………(12)

from equations (4), (11) and (12), it is possible to obtain:

as can be seen from equation (13), after the measurement process shown in fig. 2, 3, 4, and 5 is completed, the signals S sent from the receiving antennas to the signal receiving apparatus are obtained respectively₁、M₁、S₂、M₂And calculating to obtain the reflection performance of the wall surface of the darkroom to be measured.

The specific measurement steps are as follows:

i) as shown in FIG. 2, the transmitting and receiving antenna is placed on the antenna stand to aim at the wall surface of the darkroom to be measured, the distance is measured to be d, the signal generator generates a signal, the signal is radiated to the space through the transmitting antenna, the signal is received by the receiving antenna, and S is obtained₁；

ii) keeping the transmitting-receiving antenna and the antenna support stand fixed, as shown in FIG. 3, placing a reference metal plate at the wall surface of the darkroom to be measured, repeating the above measurement steps to obtain a received signal M₁；

iii) as shown in FIG. 5, the transmitting/receiving antenna is placed on the antenna support stand, the whole is rotated 180 degrees along the horizontal direction, so that the transmitting/receiving antenna faces away from the wall surface of the darkroom to be measured and faces the space of the darkroom, and the relative positions of the transmitting/receiving antenna and the antenna support stand are kept consistent with those in FIG. 2, the measurement step is repeated, and the received signal S is obtained₂；

iv) keeping the transmitting-receiving antenna and the antenna support stand fixed, as shown in fig. 5, placing a reference metal plate at the wall position of the darkroom to be measured, and repeating the above measuring steps to obtain a received signal M2;

v) calculating according to the formula (13) to obtain the reflection performance of the wall surface of the tested darkroom.

The invention achieves the following significant beneficial effects:

the realization is simple, include: providing a tested darkroom, arranging an antenna support stand in the tested darkroom, placing a transmitting antenna and a receiving antenna on the antenna support stand, and keeping the relative positions of the transmitting antenna and the receiving antenna and the antenna support stand fixed; the antenna support platform is directly opposite to the wall surface of the darkroom to be measured, and a first reflection signal of the wall surface of the darkroom to be measured is obtained; placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the antenna support stand right opposite to the wall surface of the darkroom to obtain a first reflection signal of the reference metal plate; measuring the wall surface of the darkroom by the back of the antenna bracket to obtain a second reflected signal of the wall surface of the darkroom to be measured; placing a reference metal plate at the position of the wall surface of the darkroom to be measured, and measuring the back of the antenna bracket to the wall surface of the darkroom to obtain a second reflected signal of the reference metal plate; and calculating the reflection performance of the wall surface of the tested darkroom according to the correlation among the first reflection signal of the wall surface of the tested darkroom, the first reflection signal of the reference metal plate, the second reflection signal of the wall surface of the tested darkroom and the second reflection signal of the reference metal plate. The reflection performance of the wall surface of the tested darkroom is calculated by changing the measurement direction and selecting a reasonable measurement method while the wall surface of the darkroom or the reference metal plate reflection signal does not need to be separated. By using the method, the truncation error in the signal time-frequency domain conversion process can be reduced, the influence of the direct coupling signal of the receiving and transmitting antenna and the space stray signal on the reflection signal can be effectively reduced, the measurement accuracy of the reflection performance of the darkroom is improved, and the measurement error is reduced.

Any other suitable modifications can be made according to the technical scheme and the conception of the invention. All such alternatives, modifications and improvements as would be obvious to one skilled in the art are intended to be included within the scope of the invention as defined by the appended claims.