KR102614394B1 - Method for arranging array plane of phase array antenna - Google Patents

Abstract

The present invention includes a process of radiating an electric field from a probe to an area of an active phased array antenna in which a plurality of radiation elements are arranged, a process of calculating a digital input of the radiation element, and the amplitude and phase of the electric field input to the radiation element. A process of compensating, a process of compensating for an electric field value received by a radiation element due to the pattern of the probe, and a radiation element using the electric field value radiated from the probe and received by the array antenna and the electric field value received from each radiation element. We present a method for aligning the array surface of an active phased array antenna that includes a process to exclude mutual interference.

Description

{Method for arranging array plane of phase array antenna}

The present invention relates to an active phased array antenna, and particularly to a method for aligning the array surface of an active phased array antenna using proximity electric field data.

Recent radars are being developed in the form of multi-function radars that can simultaneously search and track multiple targets. To perform the functions required for a multi-function radar, the antenna is implemented in the form of an active phased array antenna. The active phased array antenna has features that enable digital beam formation, such as real-time beam steering, forming multiple beams at the same time, and removing received beams in a specific direction.

Active phased array antennas are being developed into various forms as processing of a relatively small number of transmission and reception channels is required to process multiple multi-channels. For these active phased array antennas, it is important to prevent mismatch by correcting the gain and phase between each channel in a close electric field or a nuclear electric field. In addition, with the development of radar, it is evolving from mechanical beam steering to electronic beam steering (Active Electronically Scanned Array; AESA), and various beam formation and beam steering are required according to the operating concept. For this purpose, alignment of the array surface to align the amplitude and phase of all elements is essential.

Array plane alignment is an essential process for the operation of array antennas and radars using them, and is performed to secure the performance of the antenna before radar operation. Conventional array plane alignment using proximity electric field data often uses the back projection method and the point to point (P2P) method. The back projection method is a method of measuring the proximity electric field and then measuring the amplitude and phase of each radiation element, while the point-to-point method is a method of measuring all radiation elements sequentially using a probe to obtain the amplitude and phase of all radiation elements.

However, the conventional back projection and point-to-point methods have the disadvantage that the measurement time is very long. In addition, in the case of back projection, the electric field value must be measured for an area 4 to 5 times the area of the antenna array surface to be measured, and there is a disadvantage that the calculated phase of the element may have an error due to mutual coupling. . In addition, the point-to-point method is a method of measuring the electric field value at the center position of each radiating element in the proximity electric field measurement area. Although the phase error is smaller than that of back projection, the point-to-point method also requires the number of measurements equal to the number of radiating elements. The downside is that it takes a long time.

Korean Patent No. 10-1564729 Korean Patent No. 10-1564730

Hee-min Lee, Do-hoon Kim, Il-tak Han "Design of Active Phased Array Radar Sub-Array Receiver" Journal of the Korea Institute of Information and Communications Technology Vol. 23, no. 5: 568-573, May 2019.

The present invention proposes a method for aligning the array plane of an active phased array antenna that can shorten the array plane alignment time.

The present invention proposes a method for aligning the array surface of an active phased array antenna, which can radiate an electric field to one area of the active phased array antenna and shorten the array plane alignment time through processes such as amplitude and phase compensation.

The method of aligning the array surface of an active phased array antenna according to embodiments of the present invention includes a process of radiating an electric field from a probe to an area of an active phased array antenna where a plurality of radiation elements are arranged, and calculating a digital input of the radiation elements. A process of compensating the amplitude and phase of an electric field input to the radiation element, a process of compensating an electric field value received by the radiation element due to the pattern of the probe, and an electric field value radiated from the probe and received by the array antenna. and a process of excluding mutual interference of the radiation elements using the electric field value received from each radiation element.

The array antenna has a plurality of radiation elements arranged in the .

The probe has a hemispherical pattern on a radiation surface that radiates an electric field opposite the active phased array antenna.

The process of calculating the digital input of the radiation element converts the analog electric field radiated from the probe into a digital value using an analog-to-digital converter connected to the array antenna.

The difference in amplitude and phase of the electric field input to the radiation element, which occurs depending on the position of the radiation element in the array antenna, is compensated using [Equation 1], and a matrix as in [Equation 2] It is displayed as

The process of compensating the electric field value received by the radiation element due to the pattern of the probe includes calculating the raw electric field E plane value and H plane value of the probe, and using the raw electric field E plane value and H plane value of the probe. spherical coordinate system considering the probe pattern The electric field value of the probe at It includes the process of calculating .

The probe's E-plane value and H-plane value are calculated using [Equation 3] and [Equation 4].

Spherical coordinate system considering the probe pattern The electric field value of the probe at is calculated as in [Equation 5] to calculate the electric field value of the probe received by each radiation element.

The electric field value of the probe received by each radiation element in the array antenna calculated using [Equation 5] is expressed as an electric field value matrix (E _probe ) as shown in [Equation 6].

The process of excluding mutual interference of the radiation elements includes a first process of calculating a matrix (M) of the mutual combination value of each of the radiation elements, and an electric field value matrix (E _RX ) radiated from the probe and received by the array antenna. A second process of calculating, a third process of calculating an electric field value matrix (E _R ) according to the distance between the probe and the radiation element, an electric field value matrix (E _RX ) received by the array antenna, the probe and the radiation element Copy using the electric field value conjugate matrix (E _R *) according to the distance between the two, the electric field value conjugate matrix (E _probe *) received from the radiation elements in [Equation 6], and the mutual coupling value matrix (M) of each radiation element. It includes a fourth process to exclude mutual interference of elements.

The first process of calculating the mutual combination value matrix (M) of each of the radiation elements includes supplying a signal to any first radiation element among a plurality of radiation elements connected to the network analyzer, and A process of calculating the sum of the returning signal and the signal radiated from the first radiation element to a plurality of radiation elements and then returned to the network analyzer from the remaining radiation elements except the first radiation element as in [Equation 7], and the [ A process of expressing Equation 7] as [Equation 8] from compensation of the amplitude and phase of the electric field input to the radiation element calculated from [Equation 1], and [Equation 7] or [Equation 8] It includes the process of displaying the mutual combination value of each radiation element using ] as a matrix as shown in [Equation 9].

The electric field value matrix (E _RX ) radiated from the probe and received by the array antenna is calculated as [Equation 10].

Multiply _the electric field value matrix (E _R By multiplying the conjugate matrix (E _probe *) by elements and subtracting the mutual coupling value matrix (M) of each radiating element, mutual interference of the radiating elements is excluded as shown in [Equation 11].

A method of aligning the array surface of an active phased array antenna according to an embodiment of the present invention includes a process of radiating an electric field to one area of the active phased array antenna, a process of calculating digital inputs of all radiation elements, and a plurality of array antennas. It may include a process of compensating the amplitude and phase of the electric field input to the radiation element, a process of compensating a measurement probe pattern, and a process of excluding mutual interference of the radiation elements. That is, the present invention radiates an electric field to one area, for example, the center area, of an active phased array antenna, compensates for the amplitude and phase of the electric field input to the radiation element, and compensates for the measurement probe pattern, and excludes mutual coupling of the radiation elements. It can be implemented by doing.

Therefore, the present invention can efficiently align the array surface of an active phased array antenna with multiple channels with a single measurement, and has the effect of reducing time and cost.

1 is a flowchart illustrating a method for aligning the array surface of an active phased array antenna according to an embodiment of the present invention.
Figure 2 is a configuration diagram of a device for implementing a method for aligning the array surface of an active phased array antenna according to an embodiment of the present invention.
Figure 3 is a conceptual diagram for explaining an electric field radiated by an active phased array antenna according to an embodiment of the present invention.
Figure 4 is a conceptual diagram for explaining the field radiation method of a probe according to an embodiment of the present invention.
Figure 5 is a conceptual diagram when an electric field is radiated from a probe to an area of an active phased array antenna in which a plurality of radiation elements are arranged according to an embodiment of the present invention.
Figure 6 is a schematic diagram explaining the structure of a probe according to an embodiment of the present invention.
Figure 7 is a schematic diagram illustrating mutual interference exclusion of radiation elements according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. These embodiments only serve to ensure that the disclosure of the present invention is complete and to convey the scope of the invention to those skilled in the art. It is provided for complete information.

Figure 1 is a flowchart for explaining a method for aligning the array surface of an active phased array antenna according to an embodiment of the present invention, and Figure 2 is a flowchart for implementing a method for aligning the array surface of an active phased array antenna according to an embodiment of the present invention. This is the configuration diagram of the device. In addition, FIG. 3 is a conceptual diagram for explaining an electric field radiated to one area of an active phased array antenna according to an embodiment of the present invention, and FIG. 4 is a conceptual diagram for explaining an electric field radiation method of a probe. And, FIG. 5 is a conceptual diagram when an electric field is radiated from a probe to an area of an antenna where a plurality of radiation elements are arranged, and FIG. 6 is a schematic diagram for explaining the structure of a probe according to an embodiment of the present invention, and FIG. 7 is a schematic diagram to explain the exclusion of mutual interference of radiation elements.

Referring to FIG. 1, the method for aligning the array surface of an active phased array antenna according to an embodiment of the present invention includes a process (S100) of radiating an electric field to one area of the active phased array antenna where a plurality of radiation elements are arranged, and a plurality of A process of calculating the digital input of the radiation element (S200), a process of compensating the amplitude and phase of the electric field simultaneously input to a plurality of radiation elements (S300), a process of compensating the probe pattern (S400), and A process for excluding mutual interference (S500) may be included. In order to implement this array plane alignment method, as shown in FIG. 2, an active phased array antenna 100 in which a plurality of radiation elements are arranged, and one of the array antennas 100 are spaced a predetermined distance apart from the array antenna 100. A probe 200 that radiates an electric field to an area, an analog-digital converter (ADC) 300 that converts the electric field energy radiated from the probe 100 and input to a plurality of radiation elements into digital values, and , a first compensation unit 400 that compensates for the amplitude and phase of an electric field simultaneously entering a plurality of elements, a second compensation unit 500 that compensates for the probe pattern, and an interference exclusion unit that excludes mutual interference of radiation elements ( 600). The method of aligning the array surface of the active phased array antenna according to an embodiment of the present invention will be described in more detail for each process as follows.

S100: An electric field is radiated from the active phased array antenna 100 in which a plurality of radiation elements are arranged and the probe 200 spaced apart by a predetermined distance to one area of the array antenna 100. At this time, the probe 200 may radiate an electric field toward the center of the array antenna 100, for example. Of course, the probe 200 may radiate an electric field to an area off the center of the array antenna 100, but in the present invention, unlike the prior art, it is important to radiate the electric field to one area of the array antenna 100. At this time, the area where the electric field is radiated may be a radiation element or an area corresponding to the gap between the radiation elements.

As shown in FIG. 3, the array antenna 100 has a plurality of radiation elements arranged in one direction and another direction orthogonal thereto. For example, the array antenna 100 is implemented as an approximately square in which N radiation elements are arranged in the horizontal direction (y direction) and M radiation elements are arranged in the vertical direction (x direction). Additionally, an electric field may be radiated from the probe 200 to the exact center of the array antenna 100. Here, N and M, which represent the number of radiation elements in the horizontal and vertical directions, are each integers of 1 or more, and N and M may be the same number or different numbers. At this time, the N radiation elements in the horizontal direction may be arranged at equal intervals, the M radiation elements in the vertical direction may also be arranged at equal intervals, and the radiation elements arranged in the horizontal direction and the radiation elements arranged in the vertical direction may be arranged at equal intervals. The same spacing can be maintained. That is, a plurality of radiation elements can be arranged horizontally and vertically while maintaining equal spacing. However, the horizontal radiation elements and the vertical radiation elements may be arranged at different intervals. Therefore, if N and M are the same number and the radiation elements are kept at equal intervals, the array antenna 100 can be implemented as a square, and if N and M are different numbers and the radiation elements are kept at different intervals, the array antenna 100 can be implemented as a rectangle.

Meanwhile, the probe 200 as shown in FIG. 4 can be used to radiate an electric field. That is, as shown in FIG. 4(a), the signal generator 210 may be connected to the probe 200 to radiate an electric field to the center of the array antenna 100, and as shown in FIG. 4(b) As shown, the array antenna 100 and the probe 200 may be connected. As shown in FIG. 4(b), when the signal generator 210 is not used, the role of the signal generator 210 can be replaced by using the digital transmitting and receiving device of the array antenna 100. That is, rather than connecting the probe 200 and the radiation elements to obtain the electric field values of the plurality of radiation elements, the probe 200 only radiates electric field energy. Meanwhile, the probe 200 may have a predetermined pattern. That is, one surface of the probe 200 that faces the array antenna 100 and radiates an electric field, that is, the electric field radiation surface of the probe 200, may have a predetermined pattern. At this time, the radiation surface of the probe 200 may be formed in a hemispherical shape, that is, round.

As described above, the present invention radiates an electric field using a probe 200 to an area, for example, the center area, of the array antenna 100 in which a plurality of radiation elements are arranged at predetermined intervals in one direction and the other direction. can do.

S200: When an electric field is radiated toward an area of the array antenna 100 where a plurality of radiation elements are arranged, the electric field energy radiated from the probe 200 is transmitted through the space between the probe 200 and the array antenna 100. It is input as a copy element. The electric field energy input to the radiation element is RF (Analog), and is converted to a digital value through the analog-digital converter (ADC) 300 of the digital transmission and reception device connected to the array antenna 100. Through this process, the digital electric field value input to the radiation element can be obtained. That is, analog electric field energy is radiated to N × M radiation elements of the array antenna 100 through the probe 200, and the electric field values input to the plurality of radiation elements are converted to digital values through the ADC 300. The digital values of the plurality of radiation elements are obtained for each radiation element. That is, the digital input x[n, m] of the electric field input from the probe 200 of the N×M radiation element is calculated.

S300: FIG. 5 is a conceptual diagram when an electric field is radiated from the probe 200 to an area of the array antenna 100 where a plurality of radiation elements are arranged in the x and y directions. As shown in Figure 5, M radiation elements are arranged in the x direction and N radiation elements are arranged in the y direction to form an array antenna 100. If these radiation elements are expressed as (x, y, z) coordinates, M radiation elements are arranged in the x direction, so the radiation elements arranged in the x axis range from (x ₁ , y ₁ , z ₁ ) to (x _M , y ₁ , z ₁ ), and since N radiation elements are arranged in the y direction, the radiation elements arranged in the y axis range from (x ₁ , y ₁ , z ₁ ) to (x _M , y _N , z ₁ ) It is expressed as coordinates. An electric field is radiated from the probe 200 spaced apart from the array antenna 100 in the z direction to one area of the array antenna 100. Here, the distance between the probe 200 and an area of the array antenna 100 where the electric field is radiated is denoted as B, the closest distance between the probe 200 and the array antenna 100 is denoted as C, and B and The angle between C is θ. In addition, the distance between one area of the array antenna 100 from which the electric field is radiated from the (x ₁ , y ₁ , z ₁ ) coordinates is and the distance from the (x ₁ , y ₁ , z ₁ ) coordinates to the probe 200 is It is indicated as .

However, differences in the amplitude and phase of the electric field occur depending on the location of the radiation element in the array antenna 100, and compensation for this occurs. That is, differences in the amplitude and phase of the electric field coming from a region of the array antenna 100 where the electric field is radiated from the probe 200 to the radiation element are generated depending on the position of the radiation element. This is because a plurality of radiation elements of the array antenna 100 have different distances from the electric field radiation area, so all radiation elements do not receive the same electric field energy. Since the electric field energy received by the radiation element is different for each radiation element, the mutual value also varies. As the distance from the center of the array antenna 100 from which the electric field is radiated increases, the electric field value of the radiation element decreases, and differences in the amplitude and phase of the electric field occur depending on the distance from the center. At this time, since the amplitude of the electric field is inversely proportional to the square of the distance, this is used to compensate for the change in amplitude according to the distance. Additionally, since the phase value according to the distance can be obtained using the wavelength, the phase is compensated using this. That is, the first compensation unit 400 compensates for the amplitude and phase of the electric field input to the plurality of radiation elements constituting the array antenna 100 using [Equation 1] below.

Here, A ₀ is the amplitude of the electric field radiating from the probe, is the distance between an area of the array antenna from which the electric field is radiated from the radiation element at the coordinates (x ₁ , y ₁ , z ₁ ), is the distance from the radiation element at coordinates (x ₁ , y ₁ , z ₁ ) to the probe, and λ is the wavelength of the electric field radiated from the probe. λ is defined as c/f, where c is the speed of light and f is the operating frequency.

Compensation of the phase and amplitude of the radiation element according to [Equation 1] can be expressed as a matrix as in [Equation 2]. That is, [Equation 2] is a matrix (E _R ) of electric field values according to the distance between the probe and the radiation element calculated by [Equation 1]. Here, for example is the electric field value according to the distance from the probe of the radiation element at the (1,1) position. in other words, is the electric field value according to the distance from the probe of the first radiation element in the x and y directions.

S400: When an electric field is radiated from the probe 200 to one area of the array antenna 100, the electric field energy radiated from the probe 200 is received by the array antenna 100 consisting of a plurality of radiation elements. At this time, compensation of the probe 200 pattern is necessary for accurate compensation of the digital electric field value input to the radiation element. That is, the probe pattern may have a hemispherical shape, that is, a round pattern, on one side of the probe 200 facing the array antenna 100 where the electric field is radiated, that is, the electric field radiation surface of the probe 200. You can. Since the probe 200 is formed in a hemispherical pattern, the electric field can reach all areas of the array antenna 100. At this time, because the probe 200 has a hemispherical pattern, the electric field reaches the radiating elements close to the probe 200 quickly, but the electric field reaches the radiating elements far from the probe 200 late. Therefore, compensation of the probe 200 pattern is necessary, and for this, the raw field value of the probe pattern must be calculated. The nuclear field value of the probe pattern can be calculated using [Equation 3] and [Equation 4], respectively. That is, the second compensation unit 500 can calculate the E-plane value and H-plane value of the probe pattern's raw field using [Equation 3] and [Equation 4], respectively. there is. A typical probe is made of a waveguide, and calculates the nuclear field value and atomic field value according to the waveguide mode. Meanwhile, to explain the structure of the probe pattern for deriving [Equation 3] and [Equation 4], the structure of the probe is shown in FIG. 6. That is, Figure 6 is a schematic diagram for explaining the structure of a probe according to an embodiment of the present invention. As shown in FIG. 6, the probe has an approximately rectangular shape consisting of two long sides opposing each other and two short sides perpendicular to the long sides and opposing each other. At this time, the radiation surface of the probe has a hemispherical pattern. In addition, the length of the long side is a, and the length of the short side is b, and the x-axis can be said to be from a point on the probe radiation surface in the long side direction, the y-axis to be from a point to the short side, and the vertical direction to be the z-axis. Additionally, the direction of electric field radiation from the probe to the array antenna is , z-axis and radial direction ( ) is the angle with θ, the radial direction ( ) and the line segment between the x and y axes that form an angle of 90°, the angle formed between the x axis and the line segment is called ϕ.

각도에서 프로브의 원전계 E 평면값이고, 는 프로브의 원전계 H 평면값이다. 여기서, 는 정규화 전파 상수(normalized propagation constant), 는 TE₁₀ 모드의 반사 계수(reflection coefficient of TE₁₀ mode), 는 입사 TE₁₀ 모드의 임의 진폭(arbitrary amplitude of the incident TE₁₀ mode)이다. 또한, 이고 이다. Is

It is the E plane value of the probe's original electric field at an angle, is the probe's original field H plane value. here, is the normalized propagation constant, is _{the reflection coefficient of TE 10 mode} , is the arbitrary amplitude of _{the incident TE 10 mode} . also, ego am.

When electric field energy is transmitted to the array antenna 100 without considering the probe pattern, the distance between the probe 200 and the array antenna 100 becomes a straight line distance. However, considering the probe pattern, a time delay occurs depending on the position of the array antenna 100, which changes the amplitude and phase depending on the distance. Taking this into account, the amplitude and phase of the probe pattern Compensate for phase.

Therefore, a spherical coordinate system considering the pattern of the probe 200 having a hemispherical shape Electric field value of the probe 200 at can be calculated as in [Equation 5]. That is, the second compensation unit 500 calculates the raw field E-plane value and H-plane value of the probe pattern using [Equation 3] and [Equation 4], respectively, and then uses them to calculate [Equation 5] ] Spherical coordinate system considering the pattern of the probe 200 Electric field value of the probe 200 at can be calculated.

Here, r is the distance between the probe and the array antenna in the radiation direction of the probe, θ is the angle between z and the radiation direction (r), and ϕ is the line segment between x and y forming an angle of 90° with the radiation direction (r). The angle formed by the x-axis and the line segment, is a unit vector in the direction of the θ, is a unit vector in the direction of the ϕ.

Using Equation 5, the electric field value of each of the plurality of radiation elements of the array antenna 100 can be obtained. That is, the electric field value of the probe 200 received by each radiation element in the array antenna 100 can be calculated using [Equation 5]. In this way, the electric field value received from each radiation element can be expressed as a matrix, which is shown in [Equation 6]. For example, in [Equation 6] is the electric field value of the probe at the radiation element at the (1,1) position. in other words, is the electric field value of the probe received by the first radiation element in the x and y directions.

S500: Mutual interference between radiation elements is excluded using the interference exclusion unit 600. The interference exclusion unit 600 may calculate a mutual interference exclusion matrix (E _comp ) of the radiation elements. The mutual interference exclusion matrix (E _comp ) of the radiating elements is the conjugate of the electric field (E-field) value matrix (E _RX ) transmitted once from the probe and received by the array antenna and the electric field value according to the distance between the probe and the radiating element. ) It can be calculated by element-multiplying the matrix (E _R *), element-multiplying the electric field value conjugate matrix (E _probe *) received from each radiation element, and then subtracting the mutual coupling value matrix (M) of each radiation element. That is, the interference exclusion unit 600 includes an electric field ₍ E-field) value matrix (E _R Calculate the mutual coupling value matrix (M) of each _element , and calculate the electric field (E-field) value matrix (E _R *) is element-multiplied by the electric field value conjugate matrix (E _probe *) received from the radiation element in [Equation 6], and then the mutual coupling value matrix (M) of each radiation element is subtracted to obtain the mutual interference exclusion matrix of the radiation elements ( E _comp ) can be calculated. Therefore, the radiating element mutual interference exclusion process includes the first process of calculating the mutual coupling value matrix (M) of each radiating element, and the electric field (E-field) value matrix (E _RX ) transmitted once from the probe and received by the array antenna. A second process of calculating , a third process of calculating an electric field value matrix (E _R ) according to the distance between the probe and the radiation element, an electric field (E-field) value matrix (E _RX ) received by the array antenna, and [ After element-multiplying the electric field value conjugate matrix (E _R *) according to the distance between the radiation element and the probe in [Equation 1] and element-multiplying the electric field value conjugate matrix (E _probe *) received from the radiation element in [Equation 6], the radiation element A fourth process of subtracting each mutual combination value matrix (M) may be included.

Figure 7 is a schematic diagram for explaining mutual interference exclusion of radiation elements, in which a plurality of radiation elements are arranged in one direction and the other direction. That is, N radiation elements are arranged in one direction from the first radiation element (#11) to form a 1N radiation element (#1N), and M radiation elements are arranged in the other direction from the first radiation element (#11). The first MN radiation element (#MN) is arranged. In other words, N radiation elements in one direction and M radiation elements in the other direction are arranged two-dimensionally, each spaced at a predetermined distance. A plurality of radiation elements are connected to the network analyzer 610, and the network analyzer 610 transmits a signal (S ₁₁ ) to the first radiation element (#11). When the first radiation element (#11) receives the signal (S11), the first radiation element (#11) transmits the signal ( _S11 ) to the network analyzer (610). At this time, when the first radiation element (#11) transmits the signal (S ₁₁ ), the signal (S ₁₁ ) is radiated to the other plurality of radiation elements. When the plurality of radiation elements receive the radiated signal, they transmit the signal to the network analyzer 610. In FIG. 7, the signal received and radiated from the network analyzer 610 by the first radiation element (#11) is indicated as S ₁₁ , and the signal transmitted from the remaining plurality of radiation elements to the network analyzer 610 is denoted as M ₁₂ . , M ₁₃ , … ,M _1N , M _M1 , M _M2 ,… It is denoted as ,M _MN . In this way, the signal that transmits electric field energy to one radiation element and is exchanged by the remaining radiation elements through space and enters the network analyzer 610 is a mutual signal. The signal input to the network analyzer 610 is expressed as the sum of the signal returning from the network analyzer 610 from the first radiation element (#11) and the signal returning after being radiated to the plurality of radiation elements, using [Equation 7] can be expressed as follows.

Here, S _11,A is a signal input to the network analyzer 610, S _11,P is a signal input to the network analyzer 610 from the first radiating element, M ₁₂ , M ₁₃ , ??,M _1N , M _M1 , M _M2 ,?? M _MN is a signal input to the network analyzer 610 from the remaining radiation elements other than the first radiation element (#11). That is, the signal input to the network analyzer 610 is a signal input to the network analyzer 610 from the first copying element, and a signal input to the network analyzer 610 from the remaining copying elements excluding the first copying element. It may be the sum of .

Meanwhile, [Equation 7] can be expressed again as [Equation 8]. That is, [Equation 7] can be expressed as [Equation 8] from the compensation of the amplitude and phase of the electric field input to the radiation element, which can be calculated from [Equation 1].

As described above, the mutual coupling value of each radiation element can be calculated using [Equation 7] or [Equation 8]. Additionally, the mutual coupling value of each radiation element can be expressed as a matrix as shown in [Equation 9].

Here, M is a matrix of mutual coupling values between radiating elements, and EM ₁₁ , EM ₁₂ and EM _1N are the mutual couplings received from radiating elements at positions (1,1), (1,2) and (1,N), respectively. It is the sum of values. Similarly, EM _21, EM ₂₂ and EM _2N are the sum of the mutual coupling values received from the radiating elements at positions (1,2), (2,2) and (2,N) respectively, EM _M1, EM _M2 and EM _MN is the sum of the mutual coupling values received from the radiation elements at (M,1), (M,2), and (M,N) positions, respectively.

Meanwhile, the data received when the probe radiates, that is, the electric field (E-field) value (E _RX ) transmitted once from the probe and received by the array antenna 100 can be expressed in a matrix as shown in [Equation 10].

_{Here , E R} This is the electric field value received from the radiation elements at (1,1), (1,2), and (1,N) positions. Similarly, E _R2,1 , E _R2,2 and E _R2,N are the electric field values received at the radiating elements at positions (2,1), (2,2) and (2,N), respectively, and E _RM,1 , E _RM,2 and E _RM,N are the electric field values received from the radiation elements at the (M,1), (M,2) and (M,N) positions, respectively.

Therefore, the electric field (E-field) value matrix (E _RX ) transmitted once from the probe and received by the array antenna, the electric field value matrix (E _probe ) received from each radiation element, and the mutual coupling value matrix of each radiation element ( Using M), mutual interference of radiation elements can be excluded as shown in [Equation 10].

_{Here ,} and element-multiply the conjugate matrix (E _R *) of the electric field value according to the radiation element distance, and element-multiply the conjugate matrix (E _probe *) of the probe electric field value at each radiation element location, then [mathematics It can be calculated by subtracting the mutual coupling value matrix (M) of each radiation element in [Equation 9]. The element product can be defined as [Equation 12]. In other words, it can be expressed as AXB by multiplying the elements of matrix A and matrix B.

As described above, the method for aligning the array surface of an active phased array antenna according to an embodiment of the present invention includes a process of radiating an electric field to one area of the active phased array antenna (S100) and a process of calculating digital inputs of all radiation elements. (S200), a process of compensating the amplitude and phase of the electric field input to the plurality of radiation elements of the array antenna (S300), a process of compensating the measurement probe pattern (S400), and a process of excluding mutual interference of the radiation elements. (S500) may be included.

In addition, the process of excluding mutual interference of the radiation elements (S500) includes the first process of calculating the mutual combination value matrix (M) of each radiation element, and transmitting once from the probe and receiving it with the array antenna. A second process of calculating the electric field (E-field) value matrix (E _RX ), a third process of calculating the electric field value matrix (E _R ) according to the distance between the probe and the radiation element, and the electric field received by the array antenna ₍ E-field) Value matrix (E _R It may include a fourth process of element multiplying the conjugate matrix (E _probe *) and then subtracting the mutual coupling value matrix (M) of each radiation element. Ultimately, the present invention is a method of aligning the array surface of an active phased array antenna, which includes a process of radiating an electric field to one area of the active phased array antenna (S100), a process of calculating digital inputs of all radiation elements (S200), and an array antenna. A process of compensating the amplitude and phase of the electric field input to a plurality of radiation elements (S300), a process of compensating the measurement probe pattern (S400), and a process of calculating the mutual coupling value matrix (M) of each radiation element. , a process of calculating an electric field ₍ E-field) value matrix (E _R Multiply _the electric field (E-field) value matrix (E _R A process of excluding mutual interference between radiating elements can be included by element multiplying the conjugate matrix (E _probe *) of the electric field values received from the radiating elements and then subtracting the mutual coupling value matrix (M) of each radiating element.

That is, the present invention radiates an electric field to one area, for example, the center area, of an active phased array antenna, compensates for the amplitude and phase of the electric field input to the radiation element, and compensates for the measurement probe pattern, and excludes mutual coupling of the radiation elements. It can be implemented by doing. Therefore, the present invention can efficiently align the array surface of an active phased array antenna with multiple channels with a single measurement, and has the effect of reducing time and cost.

The technical idea of the present invention as described above has been described in detail according to the above-mentioned embodiments, but it should be noted that the above-described embodiments are for explanation and not limitation. Additionally, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

100: Active phased array antenna 200: Probe
300: ADC 400: First compensation unit
500: second compensation unit 600: interference exclusion unit

Claims (14)

A process of radiating an electric field from a probe to an area of an active phased array antenna in which a plurality of radiation elements are arranged,
A process of calculating a digital input of the radiation element,
A process of compensating the amplitude and phase of the electric field input to the radiation element,
A process of compensating the electric field value received by the radiation element due to the pattern of the probe,
A process of excluding mutual interference of radiation elements using the electric field value radiated from the probe and received by the array antenna and the electric field value received from each radiation element,
The difference in amplitude and phase of the electric field input to the radiation element, which occurs depending on the position of the radiation element in the array antenna, is compensated using [Equation 1], and a matrix as in [Equation 2] Method for aligning the array surface of an active phased array antenna, represented by (E _R ).
[Equation 1]

Here, A ₀ is the amplitude of the electric field radiating from the probe, is the distance between an area of the array antenna from which the electric field is radiated from the radiation element at the coordinates (x ₁ , y ₁ , z ₁ ), is the distance from the radiation element at coordinates (x ₁ , y ₁ , z ₁ ) to the probe, and λ is the wavelength of the electric field radiated from the probe. λ is defined as c/f, where c is the speed of light and f is the operating frequency.
[Equation 2]

Here, for example , ,… is the electric field value according to the distance from the probe at each location of the radiation element.
The method according to claim 1, wherein the array antenna has a plurality of radiation elements arranged in the A method of aligning the array surface of an active phased array antenna that radiates an electric field toward the target.
The method of claim 2, wherein the probe has a radiation surface that radiates an electric field opposite the active phased array antenna and has a hemispherical pattern.
The method of claim 3, wherein the process of calculating the digital input of the radiation element includes,
A method of aligning the array surface of an active phased array antenna that converts the analog electric field radiated from the probe into a digital value by using an analog-to-digital converter connected to the array antenna.
delete The method of claim 4, wherein the process of compensating for the electric field value received by the radiation element due to the pattern of the probe includes,
A process of calculating the raw field E plane value and H plane value of the probe,
A spherical coordinate system considering the probe pattern using the original E plane value and H plane value of the probe The electric field value of the probe at Array plane alignment method of an active phased array antenna including the process of calculating .
The method of claim 6, wherein the raw field E plane value and H plane value of the probe are calculated using [Equation 3] and [Equation 4].
[Equation 3]

[Equation 4]

is the electric field (E-field) value of the probe at the θ angle, is the magnetic field (H-field) value of the probe. here, is the normalized propagation constant, is _{the reflection coefficient of TE 10 mode} , is _{the arbitrary amplitude of the incident TE 10 mode} , is the arbitrary amplitude of _{the incident TE 10 mode} . also, ego am.
The method of claim 7, wherein a spherical coordinate system considering the probe pattern The electric field value of the probe at is a method of aligning the array surface of an active phased array antenna that calculates the electric field value of the probe received by each radiation element by calculating as in [Equation 5].
[Equation 5]

Here, r is the distance between the probe and the array antenna in the radiation direction of the probe, θ is the angle between the probe and the vertical direction (z-axis) and the radiation direction (r), and ϕ forms an angle of 90° with the radiation direction (r). The angle formed between the x-axis and the line segment between the long side direction (x-axis) and the short side direction (y-axis) of the probe, is a unit vector in the direction of the θ, is a unit vector in the direction of the ϕ.
The method of claim 8, wherein the electric field value of the probe received by each radiation element in the array antenna calculated using [Equation 5] is expressed as an electric field value matrix (E _probe ) as in [Equation 6]. Active phased array antenna. Array surface sorting method.
[Equation 6]

here, is the electric field value of the probe at the radiation element at the (1,1) position.
The method of claim 9, wherein the process of excluding mutual interference of the radiation elements includes,
A first process of calculating the mutual coupling value of each of the radiation elements and displaying it as a matrix (M),
A second process of calculating the electric field value radiated from the probe and received by the array antenna and displaying it as a matrix (E _RX );
A third process of calculating an electric field value matrix (E _R ) according to the distance between the probe and the radiation element,
_The electric field value matrix ( _{E R} A method of aligning the array surface of an active phased array antenna including a fourth process of excluding mutual interference of radiation elements using a mutual coupling value matrix (M).
The method of claim 10, wherein the first process of calculating the mutual combination value matrix (M) of each of the radiation elements includes,
A process of supplying a signal to any first radiation element among a plurality of radiation elements connected to a network analyzer;
The sum of the signal returning from the first radiation element and the signal radiated from the first radiation element to a plurality of radiation elements and then returning to the network analyzer from the remaining radiation elements excluding the first radiation element is expressed as [Equation 7] The process of seeking,
A process of expressing [Equation 7] as [Equation 8] from compensation of the amplitude and phase of the electric field input to the radiation element that can be calculated from [Equation 1],
A method of aligning the array surface of an active phased array antenna, including the process of displaying the mutual coupling value of each radiation element using [Equation 7] or [Equation 8] as a matrix as in [Equation 9].
[Equation 7]

Here, S _11,A is a signal input to the network analyzer, S _11,P is a signal input from the first radiating element, M ₁₂ , M ₁₃ , … ,M _1N , M _M1 , M _M2 ,… M _MN is a signal input from the remaining radiation elements other than the first radiation element (#11).
[Equation 8]

[Equation 9]

Here, M is a matrix of mutual coupling values between radiating elements, and EM ₁₁ , EM ₁₂ and EM _1N are the mutual couplings received from radiating elements at positions (1,1), (1,2) and (1,N), respectively. It is the sum of values. Similarly, EM _{21 ,} EM ₂₂ and EM _2N are the sum of the mutual coupling values received from the radiating elements at positions (1,2), (2,2) and (2,N) respectively, EM _{M1 ,} EM _M2 and EM _MN is the sum of the mutual coupling values received from the radiation elements at (M,1), (M,2), and (M,N) positions, respectively.
The method of claim 11, wherein the electric field value matrix (E _RX ) radiated from the probe and received by the array antenna is expressed as [Equation 10].
[Equation 10]

Here, E _RX is the electric field value matrix radiated from the probe and received by the array antenna, and E _R1,1 , E _R1,2 and E _R1,N are (1,1), (1,2) and (1, N) is the electric field value received from the radiating element at the position, and E _R2,1 , E _R2,2 and E _R2,N are the radiating element at the (2,1), (2,2) and (2,N) positions, respectively. is the electric field value received at, and E _RM,1 , E _RM,2 and E _RM,N are the electric field values received at the radiation elements at (M,1), (M,2) and (M,N) positions, respectively. .
The method of claim 12, wherein _the electric field value matrix ( _{E R} A method of aligning the array surface of an active phased array antenna that excludes mutual interference of radiating elements as shown in [Equation 11] by multiplying *) by elements and then subtracting the mutual coupling value matrix (M) of each radiating element.
[Equation 11]

Here, X is the conjugate.
A device for aligning the array surface of the active phased array antenna according to any one of claims 1 to 4 and claims 6 to 13, comprising:
an array antenna in which a plurality of radiation elements are arranged in one direction and another direction perpendicular thereto;
a probe spaced apart from the array antenna and radiating an electric field to an area of the array antenna;
an analog-to-digital converter that converts electric field energy radiated from the probe and input to a plurality of radiation elements into digital values;
a first compensation unit that compensates for the amplitude and phase of an electric field coming into a plurality of elements;
a second compensation unit that compensates for an electric field value received by the radiation element due to the pattern of the probe;
An array plane alignment device for an active phased array antenna, including an interference exclusion unit that excludes mutual interference between radiation elements using the electric field value radiated from the probe and received by the array antenna and the electric field value received from each radiation element.

Images