KR102089545B1 - Thermal radiating apparatus having single channel for free space active antenna, and active antenna - Google Patents

Abstract

According to the present invention, suggested are a radiation apparatus for a free-space active antenna with a single flow path, capable of increasing thermal reliability, and an active antenna thereof. The apparatus includes: a plurality of plate parts arranged in a first direction, extended in a second direction and coming in thermal contact with transmission and reception elements of an active antenna; an inlet header part extended in the first direction, and connected to an end of the plate parts; an outlet header part extended in the first direction, and connected to the other end of the plate parts; and a cooling fluid circulation part supplying cooling fluids to the plate parts and collecting cooling fluids from the plate parts through the inlet header part and the outlet header part. With respect to the flow of the cooling fluids, the cross-sectional area of an upstream section of the inlet header part is smaller than the cross-sectional area of a downstream section thereof, and the cross-sectional area of an upstream section of the outlet header part is larger than the cross-sectional area of a downstream section thereof. Also, when the size of a reference cross-sectional area of the inlet and outlet header parts is defined as D, the size of the cross-sectional area of the upstream section is equal to D, the size of the cross-sectional area of the downstream section is larger than D, the plate parts include a single flow path extended and bent a number of times in second and third directions, the transmission and reception elements are placed on both sides of the plate parts in the first direction, and the transmission and reception elements are arranged on both the sides in a grid form, respectively.

Description

The radiator and active antenna of a free space active antenna equipped with a single flow path {THERMAL RADIATING APPARATUS HAVING SINGLE CHANNEL FOR FREE SPACE ACTIVE ANTENNA, AND ACTIVE ANTENNA}

The present invention relates to a heat dissipation device and an active antenna of a free space active antenna equipped with a single flow path, and more specifically, a heat dissipation device of a free space active antenna with a single flow path capable of increasing the thermal reliability of the active antenna, and the same. It relates to an active antenna.

In the military system, the antenna is the core weapon system for land, sea, and aviation power, performing missions from battlefield surveillance to target strikes. Antenna antennas for weapon systems require high-performance specifications for improved detection distance, precise detection and strike.

With the development of semiconductor technology, antennas are also becoming high-performance and small-sized. Antennas for weapon systems have recently evolved from passive passive scanned array antennas to active electrically scanned array antennas.

Active phased array antennas (referred to as 'active antennas') can transmit and receive modules using semiconductor technology to improve performance and reduce size compared to conventional passive phased array antennas. In the active antenna, high-performance and high-heat transmission / reception elements are present in the transmission / reception module. Therefore, compared to the conventional passive phased array antenna, the recent active antenna has a large amount of heat generated per unit area of the transmission / reception module.

In order to maintain the performance of the active antenna, it is necessary to effectively remove heat generated from the transceiver elements through a heat dissipation design, and to allow the transceiver elements to operate in an appropriate temperature range.

The technology underlying the present invention is published in the following patent documents.

KR 10-1909684 B1 KR 10-1586794 B1 KR 10-1174637 B1

The present invention provides a heat dissipation device of a free space active antenna equipped with a single channel capable of increasing the thermal reliability of the active antenna and an active antenna having the same.

A heat dissipation device of a free-space active antenna provided with a single flow path according to an embodiment of the present invention is arranged in a first direction, extends in a second direction, and includes a plurality of plate portions that are in thermal contact with transmission / reception elements of the active antenna. ; An inlet header portion extending in the first direction and communicating with one end of the plate portion; An outlet header portion extending in the first direction and communicating with the other end portion of the plate portion; Including, through the inlet header portion and the outlet header portion, a cooling fluid circulation unit for supplying a cooling fluid to the plate portion, and recovering the cooling fluid from the plate portion, including, based on the flow of the cooling fluid, the inlet header portion When the cross-sectional area of the upstream section is smaller than the cross-sectional area of the downstream section, the exit header section has a larger cross-sectional area of the upstream section, and the size of the reference cross-sectional area of the inlet header section and the exit header section is D. The size of the cross-sectional area is equal to D, and the size of the cross-sectional area of the downstream section is greater than D, and the plate portion is formed with a single flow path extending and refracting a plurality of times in the second direction and the third direction, and the plate portion is the first. The transmission / reception elements are arranged on both sides of the direction, and the transmission / reception elements are arranged in a lattice form on both sides.

Assuming that the cross-sectional areas of the inlet header portion and the outlet header portion are constant in the first direction, if the plate portion whose flow rate value of the cooling fluid flowing therein is closest to the intermediate value is the reference plate, the upstream section and the downstream section are the reference Can be defined on a plate basis.

The reference plate communicates with the upstream section, and the reference plate can introduce and discharge cooling fluid through the upstream section.

The lattice shape is a two-dimensional lattice shape for the second direction and the third direction, and along the lattice shape, a single flow path may be formed inside the plate portion.

The inlet header portion and the outlet header portion may be spaced apart in a second direction, and the plate portion may connect the inlet header portion and the outlet header portion in a second direction between the inlet header portion and the outlet header portion.

With respect to the first direction, the flow of the cooling fluid of the inlet header portion and the flow of the cooling fluid of the outlet header portion may be formed in the same direction.

The plate portion may have a length in the second direction greater than the width in the third direction and a width in the third direction greater than the thickness in the first direction.

Each of the inlet header portion and the outlet header portion may have a length in a first direction greater than a diameter in the second and third directions.

The diameter of the inlet header portion and the outlet header portion may be smaller than the width of the plate portion and greater than the thickness of the plate portion.

The single flow path includes at least three or more extension sections and at least two or more refraction sections, the number of extension sections increases in an odd number, the number of refraction sections increases in an even number, and the flow cross section has a rectangular shape. It can contain.

The size of the cross-sectional area of the downstream section may be 1.6D.

Active antenna according to an embodiment of the present invention, a plurality of radiation elements for transmitting and receiving electromagnetic waves; A plurality of transmission / reception elements for controlling the magnitude and phase of the electromagnetic wave fed to the radiation element; It includes; the heat dissipation device in thermal contact with the transceiver element.

According to the embodiment of the present invention, the transmitting and receiving elements of the active antenna can be smoothly cooled to a desired temperature. Specifically, the cooling fluid can be smoothly cooled to a desired temperature by appropriately concentrating the cooling fluid in the plate part while properly supplying the cooling fluid to a plurality of plate parts for cooling the transmitting and receiving devices. . That is, it is possible to minimize the flow rate variation of the cooling fluid between the plurality of plate parts, and maximize the flow rate of the cooling fluid allocated to each transmitting and receiving element in the plate part. Therefore, it is possible to smoothly cool the temperature of the transmitting and receiving elements to a desired temperature by supplying a large amount of cooling fluid to the transmitting and receiving elements as uniformly as possible.

From this, when the active antenna is operated, the temperature of the transmitting and receiving elements can be maintained at a temperature at which the transmitting and receiving elements can stably operate. That is, it is possible to increase the thermal reliability of the active antenna, and it is possible to perform a stable task of the active antenna.

1 is a schematic diagram of an active antenna according to an embodiment of the present invention.
2 is a schematic diagram of a heat dissipation device of an active antenna according to an embodiment of the present invention.
3 is a schematic view of a plate portion according to an embodiment of the present invention.
4 is a schematic diagram of an entrance header according to an embodiment of the present invention.
5 is a schematic diagram of an outlet header portion according to an embodiment of the present invention.
6 is a schematic diagram of a single flow path according to an embodiment of the present invention.
7 to 23 are views for explaining a design method of a heat dissipation device according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and will be implemented in various different forms. Only the embodiments of the present invention are provided to make the disclosure of the present invention complete, and to fully inform the scope of the invention to those skilled in the art. The drawings may be exaggerated to describe embodiments of the present invention, and the same reference numerals in the drawings refer to the same elements.

The heat dissipation device of an active antenna according to an embodiment of the present invention (hereinafter referred to as a 'heat dissipation device') can appropriately branch and distribute the cooling fluid so as to effectively cool the high-performance and high heat transmission / reception elements provided in the active antenna. . Therefore, the heat dissipation device can maintain the temperature of the transmitting and receiving elements at a temperature at which the transmitting and receiving elements can stably operate. That is, the heat dissipation device can increase the thermal reliability of the active antenna. From this, it is possible to perform a stable task of the active antenna. Meanwhile, the heat dissipation device of an active antenna may be referred to as a heat dissipation device of a free space active antenna provided with a single flow path.

1 is a schematic view of an active antenna according to an embodiment of the present invention, FIG. 2 is a schematic view of a heat dissipation device according to an embodiment of the present invention, and FIG. 3 is a schematic view of a plate portion according to an embodiment of the present invention. In addition, FIG. 4 is a schematic diagram of an inlet header portion according to an embodiment of the present invention, FIG. 5 is a schematic diagram of an outlet header portion according to an embodiment of the invention, and FIG. 6 is a schematic diagram of a single flow path according to an embodiment of the invention.

An active antenna according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

The active antenna 1 according to an embodiment of the present invention includes a plurality of radiation elements 10 for transmitting and receiving RF signals through free space, and a plurality of transmission and reception modules 20 for performing electronic beam steering of the radiation elements 10 , And a heat dissipation device 300 for cooling the transmission / reception module 20.

The radiation element 10 may be tens to tens of thousands. The radiation element 10 may be arranged in a predetermined pattern. The radiation element 10 can emit RF signals into free space. In addition, the radiation element 10 may receive an RF signal radiated to free space. RF signals may be referred to as electromagnetic waves or radio waves.

The transceiver module 20 may be tens to tens of thousands. The transmission / reception module 20 is arranged in a checkerboard or grid form to perform its function. The transmission / reception module 20 may be connected to the radiation element 10. The transmission / reception module 20 may correspond one-to-one with the radiation element 10. The transmission / reception module 20 may contact the heat dissipation device 300. The transmission / reception module 20 may be cooled by the heat dissipation device 300.

The transmission / reception module 20 may include a plurality of transmission / reception elements 21 for controlling the size and phase of the RF signal fed to the radiation element 10, and a housing 22 in which the transmission / reception elements 21 are accommodated.

The transmission / reception device 21 may be implemented as a semiconductor device. The transmitting / receiving element 21 may receive the RF signal, electronically control the magnitude and phase of the RF signal, and transmit the RF signal to the radiation element 10. Accordingly, electronic beam steering of the RF signal emitted from the radiation element 10 to free space may be performed. The transmitting / receiving element 21 may be mounted on a circuit board. The circuit board can be accommodated in the inner space of the housing 22.

The transmitting / receiving element 21 may generate heat. The transceiving element 21 may be referred to as a heat source or a heat source. If the heat generated in the transmitting / receiving element 21 is not removed, the heat density of the transmitting / receiving element 21 becomes high, a malfunction of the transmitting / receiving element 21 may occur, or the transmitting / receiving element 21 may be damaged.

The housing 22 may be, for example, a hexahedral shape. Of course, the shape of the housing 22 may vary. The housing 22 may contact the heat dissipation device 300. Through the housing 22, heat from the transmission / reception element 21 may be transferred to the heat dissipation device 300.

The heat dissipation device 300 may be in thermal contact with the housing 22 and the transceiving element 21. Specifically, the heat dissipation device 300 may thermally contact the transceiving element 21 through the housing 22. The heat dissipation device 300 can effectively dissipate heat from the high-heat-receiving element 21 as a cooling fluid by using a cooling fluid, and satisfy the thermal performance of the active antenna 1. The cooling fluid can be in a liquid state. That is, the heat dissipation device 300 can smoothly dissipate heat from the transmission / reception elements 21 by a liquid cooling method. The heat dissipation device 300 may be referred to as a liquid cooling system of an active antenna.

It is expressed that the thermal performance of the active antenna 1 is good that the active antenna 1 satisfies the thermal requirements. The thermal requirement of the active antenna 1 is a condition in which the temperature of the transmitting / receiving elements 21 in operation is lower than a reference temperature, a condition in which the temperature deviation of the transmitting / receiving elements 21 in operation is lower than a reference temperature deviation, the operating transmitting / receiving element 21 ), The temperature distribution of which corresponds to the shape of a negative parabola.

The reference temperature means the highest temperature among the temperatures of the transmission / reception elements 21 capable of normal operation of the active antenna 1. In addition, the reference temperature deviation means a temperature deviation between the highest temperature and the lowest temperature among the temperatures of the transmitting and receiving elements 21 capable of normal operation of the active antenna 1.

In addition, the temperature distribution of the transmission / reception elements 21 means the temperature distribution of the transmission / reception elements 21 in a direction in which a plurality of plate portions 310 to be described later are listed.

Specifically, the main element among the transmitting and receiving elements 21 is selected for each plate portion 310, the order of the plurality of plate portions 310 is the horizontal axis of the graph, and the temperature of the main element is the vertical axis of the graph. , When a two-dimensional graph is shown, the shape of the graph is referred to as a temperature distribution of the transmitting and receiving elements 21.

The negative parabolic shape means a shape in which the center of the graph is generally symmetrical from side to side, and its center portion is convex upward and its peripheral portion is convex downward.

The active antenna 1 can operate most smoothly when all the above-mentioned thermal requirements are satisfied. Working smoothly means that the error between the desired beam emission angle and the actual beam emission angle of the active antenna 1 can be minimized.

1 to 6, the heat dissipation device 300 according to an embodiment of the present invention will be described in detail.

The heat dissipation device 300 according to an embodiment of the present invention is arranged in the first direction (X), extends in the second direction (Y), and thermally contacts the transceiver elements 21 of the active antenna 1 A plurality of plate portion 310, extending in the first direction (X), the inlet header portion 320 communicating with one end of the plate portion 310, extending in the second direction (Y), the plate portion ( Through the outlet header portion 330, the inlet header portion 320 and the outlet header portion 330 communicating with the other end of 310, the cooling fluid is supplied to the plate portion 310, and cooled in the plate portion 310. It includes a cooling fluid circulation unit 340 for recovering the fluid.

As the cooling fluid flows inside the inlet header part 320 and the outlet header part 330, based on the flow of the cooling fluid, as it goes from the upstream section (Du) to the downstream section (Dd), friction and flow distribution, gravity, etc. Energy is lost and pressure is reduced. Therefore, the inlet header part 320 and the outlet header part 330 are not provided in the flow distribution optimization structure described later, for example, the cross-sectional area of the inlet header part 320 and the outlet header part 330 is the first direction (X). If it is constant, the cooling fluid is linearly differentiated and distributed to the plurality of plate parts 310. In this case, the cooling fluid does not cool the transmission / reception elements 21 smoothly, and cannot satisfy the thermal performance of the active antenna 1.

Accordingly, based on the flow of the cooling fluid of the inlet header portion 320 and the outlet header portion 330, the inlet header portion 320 has a cross-sectional area of the upstream section Du smaller than that of the downstream section Dd. The header portion 330 may have a cross-sectional area of the upstream section Du that is larger than that of the downstream section Dd. The structures of the inlet header part 320 and the outlet header part 330 are referred to as a flow distribution optimization structure. Meanwhile, in order to be distinguished from the above-described flow distribution optimization structure, a structure in which the cross-sectional areas of the inlet header part 320 and the outlet header part 330 are constant along the first direction X is referred to as a flow rate distribution linear increase / decrease structure.

By the flow distribution optimization structure, it is possible to supply the cooling fluid relatively uniformly to each of the plurality of plate parts 310 to smoothly cool the transmission / reception elements 21 as a whole, and to improve the thermal performance of the active antenna 1. have.

Here, the relatively uniform, when the cross-sectional area of at least one of the inlet header portion 320 and the outlet header portion 330 is constant, a plurality of plate portions through the inlet header portion 320 and the outlet header portion 330 ( 310) means that the cooling fluid is uniform compared to the differential distribution.

That is, in the embodiment of the present invention, by the above-described structure of the inlet header portion 320 and the outlet header portion 330, the cooling fluid circulation portion 340 and the plate portion 310 of the upstream section (Du) The cooling fluid at a suitable temperature can be relatively evenly distributed to the plate sections 310 of the downstream section Dd. Through this, a plurality of plate parts 310 can perform heat dissipation of the transmitting and receiving elements 21 in consideration of the thermal performance of the active antenna 1.

Meanwhile, the flow of the cooling fluid in the inlet header portion 320 and the flow of the cooling fluid in the outlet header portion 330 with respect to the first direction X may be formed in the same direction. That is, when the cooling fluid flows from left to right in the inlet header part 320, the cooling fluid may flow from left to right in the outlet header part 330 as well.

The direction is defined as follows to facilitate describing the embodiment of the present invention. The first direction X, the second direction Y, and the third direction may be directions intersecting each other. The first direction X may be a left-right direction, and the second direction Y may be a vertical direction. The third direction Z may be a front-rear direction. Of course, these directions can be defined in various ways.

The terms are defined as follows to facilitate describing the embodiments of the present invention. Upstream means the point or portion where the cooling fluid passes relatively first. And downstream means the point or part where the cooling fluid passes relatively later.

Hereinafter, the components of the heat dissipation device 300 will be described in detail in order.

A plurality of plate portions 310 may be provided. The plate portion 310 may be arranged in the first direction (X). The plate portion 310 may extend in the second direction (Y). The plate portion 310 may be in thermal contact with the transmitting and receiving elements 21 of the active antenna 1.

The plate part 310 may be provided with transceiving elements 21 on both sides of the first direction X. Specifically, a plurality of housings 22 are disposed on both sides of the plate 310 described above, and a plurality of transmission / reception elements 21 can be accommodated in each housing 22. As described above, a plurality of transmission / reception modules 20 per one plate portion 310 may be in thermal contact.

Here, a plurality of housings 22 are disposed on each of the above-described both side surfaces of the plate portion 31 and may be arranged in the second direction (Y). The transmitting / receiving elements 21 may be arranged in the form of a lattice, respectively, on each of the above-described both side surfaces of the plate portion 31. At this time, the lattice shape may be a two-dimensional lattice shape for the second direction (Y) and the third direction.

The above-described both side surfaces of the plate portion 310 refer to surfaces facing each other in the first direction (X). The above-described both side surfaces of the plate portion 310 may be referred to as left and right side surfaces of the plate portion 310.

The plate portion 310 may connect the inlet header portion 320 and the outlet header portion 330 between the inlet header portion 320 and the outlet header portion 330 in the second direction (Y). One end portion of the plate portion 310 connected to the inlet header portion 320 is referred to as an inlet end portion or an upper end portion, and the other end portion of the plate portion 310 connected to the outlet header portion 330 is called an outlet side end portion or a lower end portion. .

The plate portion 310 has a cooling plate 311 in which the length of the second direction Y is greater than the width of the third direction Z, and the width Z of the third direction is greater than the thickness of the first direction X. ), And a single flow path 312 formed inside the cooling plate 331 along a grid shape in which the transmitting and receiving elements 21 are arranged.

The material of the cooling plate 311 may include a metal material. At this time, the metal may include aluminum. Of course, the material of the cooling plate 311 may include various metals and alloy materials thereof. The cooling plate 311 may transfer heat generated from the transmitting / receiving element 21 to a cooling fluid flowing inside the single flow path 312.

The thickness of the cooling plate 311 may be smaller than the diameter of the inlet header portion 320 and the outlet header portion 330. The width of the cooling plate 311 may be greater than the diameter of the inlet header portion 320 and the outlet header portion 330. The diameter can be a maximum, minimum or average diameter. The cooling plate 311 may have a thickness of several tens of millimeters, a width of several hundred mm, and a length of several meters.

The single flow path 312 may be formed to penetrate the inside of the cooling plate 311, or a separate cooling tube may be inserted into the cooling plate 311. As such, the single flow path 312 may be integral with the cooling plate 311, or the cooling plate 311 and the single flow path 312 may be formed with separate members coupled to each other. When the single flow path 312 is a separate cooling tube, the material of the single flow path 312 may be the same as that of the cooling plate 311.

The single flow path 312 has one end, for example, an inlet port through the inlet side end of the cooling plate 311 to communicate with the inlet header portion 320, and the other end, for example, an outlet port, through the outlet side end of the cooling plate 311. The outlet header unit 330 may be in communication. The single flow path 312 may receive the cooling fluid from the inlet header portion 320 and discharge the cooling fluid to the outlet header portion 330.

Meanwhile, 내부 may be provided on the inner surface of the single flow path 312. For example, 휜 may protrude on the inner surface of the single flow path 312, and 휜 may extend along the direction in which the single flow path 312 extends. Of course, the shape of the pin may be various, such as a spiral.

The single flow path 312 may extend and bend a plurality of times in the second direction (Y) and the third direction (Z) inside the cooling plate 311. For example, the single flow path 312 may be formed in an S shape. The single flow path 312 includes a plurality of extension sections 312a extending in the second direction Y and a plurality of refractive sections 312b refracted in the third direction Z at the ends of the extension section 312a. can do.

The single flow path 312 may include at least three or more extension sections 312a and at least two or more refraction sections 312b. The number of extension sections 312a may increase oddly, and the number of refraction sections 312b may increase evenly. The single flow path 312 may have a rectangular cross-section.

By the structure of the single flow path 312 described above, in the cooling plate 311, the transmission / reception elements in the cooling plate 311 by appropriately concentrating the cooling fluid along the lattice form in which the transmission / reception elements 21 are arranged ( 21) It is possible to maximize the flow rate of the cooling fluid allocated to each. Accordingly, the temperature of the transmitting and receiving elements 21 can be cooled to a desired temperature.

In an embodiment of the present invention, the number of plate portions 310 is N, and among them, the number of plate portions 310 located in the upstream section Du is K. That is, K plate parts 310 are listed in the upstream section Du, and N-K plate parts 310 are listed in the downstream section Dd.

The order of the plate portion 310 is based on the direction from the upstream section (Du) to the downstream section (Dd), and the first plate section (# 1) through which the cooling fluid first passes in the upstream section (Du) ), And in the upstream section (Du), the K-th plate part (#K) through which the cooling fluid passes last is called the K-th plate part (#K). In the downstream section Dd, the K + 1th plate part through which the cooling fluid first passes is referred to as a K + 1 plate part ## K + 1, and in the downstream section Dd, the cooling fluid is N-1-Kth. The plate portion passing through is referred to as an N-1 plate portion (# N-1), and an Nth plate portion passing through the cooling fluid at the downstream in the downstream section Dd is referred to as an N plate portion (#N). The K-plate part #K is a reference plate to be described later, which communicates with the upstream section Du, and allows cooling fluid to flow in and out through the upstream section Du.

The inlet header portion 320 may extend in the first direction (X). The inlet header part 320 may have a length in the first direction X larger than the diameters in the second direction Y and the third direction Z. In addition, the inlet header portion 320 may have a diameter smaller than the width of the plate portion 310 and larger than the thickness of the plate portion 310. At this time, the length of the inlet header portion 320 may be several meters, and the diameter may be several tens of millimeters.

The inlet header part 320 may be located above the plurality of plate parts 310. The inlet header part 320 may contact and communicate with one end of the plate parts 310. The inlet header portion 320 may have an upstream end connected to the cooling fluid circulation portion 340. The upstream end may also be referred to as the left end.

The inlet header part 320 may receive cooling fluid from the cooling fluid circulation part 340 and supply it to the plurality of plate parts 310. Here, based on the flow of the cooling fluid, the inlet header portion 320 has a smaller cross-sectional area of the upstream section Du than that of the downstream section Dd. Due to this structure, the cooling fluid flowing inside the inlet header portion 320 may lower the flow pressure somewhat in the upstream section Du and recover the flow pressure somewhat in the downstream section Dd. On the other hand, the cross-sectional area means a cross-sectional flow area of a cross-section, for example, a cross section crossing the first direction X, which is a direction in which the cooling fluid flows inside the inlet header part 320.

The outlet header portion 330 may extend in the first direction (X). The outlet header portion 330 may have a length in the first direction X larger than the diameters in the second direction Y and the third direction Z. In addition, the outlet header portion 330 may have a diameter smaller than the width of the plate portion 310 and larger than the thickness of the plate portion 310. At this time, the length of the outlet header portion 320 may be several meters, and the diameter may be several tens of millimeters.

The outlet header portion 330 may be spaced apart from each other in the inlet header portion 320 and the second direction (Y). The outlet header portion 330 may be located below the plurality of plate portions 310. The outlet header portion 330 may contact and communicate with the other end of the plate portions 310. The outlet header portion 330 may have a downstream end connected to the cooling fluid circulation portion 340. The downstream end may be referred to as the right end.

The outlet header part 330 may recover the cooling fluid discharged from the plurality of plate parts 310 and supply it to the cooling fluid circulation part 340. At this time, based on the flow of the cooling fluid, the outlet header portion 330 has a larger cross-sectional area of the upstream section Du than the downstream section Dd. In this case, the cross-sectional area refers to a cross-sectional flow cross-sectional area that crosses the first direction X, which is a direction in which the cooling fluid flows inside the outlet header portion 330.

By such a structure, the cooling fluid flowing inside the outlet header portion 330 can relatively increase the flow pressure in the upstream section Du and relatively lower the flow pressure in the downstream section Dd.

As the structures of the inlet header portion 320 and the outlet header portion 330 are formed as described above, through the inlet header portion 320 and the outlet header portion 330, a plurality of plate portions 310 for cooling fluid is provided. It can be supplied by branching relatively uniformly. Therefore, it is possible to minimize the flow rate variation between the plurality of plate parts 310.

When the flow rate deviation between the plurality of plate parts 310 is minimized, the temperature distribution of the transmitting and receiving elements 21 cooled by the plurality of plate parts 310 may correspond to a negative parabolic shape, and the transmitting and receiving elements 21 may The temperature may be lower than the reference temperature, and the temperature deviation of the transmitting and receiving elements 21 may be lower than the reference temperature deviation. Accordingly, the plurality of transmitting and receiving elements 21 are stably operated, so that the actual beam emission angle of the radiation elements 10 can be stably controlled to a desired beam emission angle.

The above-described upstream section Du and downstream section Dd may be defined based on a reference plate. First, the process of determining the reference plate is as follows.

It is assumed that the cross-sectional areas of the inlet header portion 320 and the outlet header portion 330 are constant in the first direction X. While supplying cooling fluid to the plurality of plate parts 310 through the inlet header part 320 and the outlet header part 330, a flow rate value of the cooling fluid flowing inside each of the plurality of plate parts 310 is obtained. Specifically, after modeling the heat dissipation device according to the comparative example in which the cross-sectional areas of the inlet header part 320 and the outlet header part 330 are constant in the first direction X, input predetermined analysis conditions, and then compute computational fluid dynamics. By using, the flow rate value of the cooling fluid flowing inside each of the plurality of plate parts 310 is obtained. Then, the plate portion having the obtained flow rate value closest to the intermediate value is determined as a reference plate.

As described above, in the exemplary embodiment of the present invention, the center plate portion is not merely structurally or geometrically defined as the reference plate, but the reference plate is determined in consideration of the flow of the cooling fluid. Accordingly, the structural design of the inlet header portion 320 and the outlet header portion 330 for distributing the cooling fluid as uniformly as possible can be performed smoothly.

When the reference plate is determined, an upstream section (Du) and a downstream section (Dd) can be defined. Specifically, a predetermined section between the reference plate and the next plate is defined as a midstream section (Dm). At this time, the next plate means the plate portion closest to the reference plate among the plate portions spaced in the direction in which the cooling fluid flows from the reference plate.

Subsequently, the upstream section (Du) is determined from the upstream ends of the inlet header section (320) and the outlet header section (330) to before the middle section (Dm). In addition, a downstream section Dd is defined from the middle section Dm to the downstream ends of the inlet header section 320 and the outlet header section 330. The midstream section Dm may have a diffuser shape. Of course, the shape can vary.

According to the size relationship between the cross-sectional area of the upstream section (Du) and the cross-sectional area of the downstream section (Dd) of each of the inlet header part (320) and the outlet header part (330), the degree of flow distribution described later to the plurality of plate parts (310) May vary.

For example, if the size of the reference cross-sectional area of the inlet header portion 320 and the outlet header portion 330 is D, the size of the cross-sectional area of the upstream section Du of the inlet header portion 320 and the outlet header portion 330 is D and Same, and the size of the cross-sectional area of the downstream section Dd may be greater than D. More specifically, the size of the cross-sectional area of the downstream section Dd may be 1.6D.

Alternatively, when the size of the aforementioned reference cross-sectional area is D, the cross-sectional area of the upstream section Du may be smaller than D, and the cross-sectional area of the downstream section Dd may be larger than D. Specifically, the size of each cross-sectional area may be 0.8D and 1.6D.

Here, the size D of the reference cross-sectional area may be equal to a value calculated by summing the flow cross-sectional areas of each of the single flow paths 320 of the plurality of plate parts 310. For example, the size D of the reference cross-sectional area is equal to the sum of the flow cross-sectional areas of the single flow paths 320 respectively provided in the plurality of plate parts 310.

Due to the size relationship described above, the degree of flow distribution between the plurality of plate parts 310 may be close to zero. At this time, as the cooling fluid is uniformly distributed to the plurality of plate parts 310, the degree of flow rate distribution approaches 0, and as the cooling fluid is linearly differentially distributed to the plurality of plate parts 310, the degree of flow rate distribution is 0. Away from That is, the cooling fluid may be uniformly distributed to the plurality of plate parts 310 as much as possible.

The cooling fluid circulation part 340 may supply the cooling fluid to the plate part 310 through the inlet header part 320 and the outlet header part 330, and recover the cooling fluid from the plate part 310. The cooling fluid circulation unit 340 receives the cooling fluid, cools it to a desired temperature, and supplies a cooler 341 capable of discharging it again, and cooling fluid discharged from the cooler 341 to the inlet header part 320 The supply unit 342, the recovery unit 343 for recovering the cooling fluid from the outlet header 330 and flowing into the cooler 341, the cooler 341 and the supply unit 342 and the recovery unit 343 are connected, and It may include a rotary joint 344 to control the overall flow. The configuration and method of the cooling fluid circulation unit 340 may be various other than this.

The cooling fluid may include various refrigerants capable of smoothly cooling the transceiving element 21. The components of the cooling fluid may include antifreeze. At this time, the antifreeze may include ethylene glycol. That is, the cooling fluid may be an aqueous solution of ethylene glycol.

According to an embodiment of the present invention, after the cooling fluid flows into the inlet header part 320 through the cooling fluid circulation part 340, it is appropriately branched from the inlet header part 320 to each plate part 310, and a single Heat is recovered from the transmission / reception element 21 through the flow path 312. Then, the cooling fluid is recovered to the cooling fluid circulation part 340 through the outlet header part 330, cooled, and then introduced into the inlet header part 320 again. The heat dissipation device 300 may repeat this to perform a heat dissipation function.

7 to 23 are views for explaining a design method of a heat dissipation device according to an embodiment of the present invention.

7 to 15 are views for explaining a preliminary design process of a heat dissipation device according to an embodiment of the present invention, and FIGS. 16 to 18 are views for explaining an optimization design process of a heat dissipation device according to an embodiment of the present invention to be. In addition, FIGS. 19 to 23 are views for explaining a thermal analysis process according to an embodiment of the present invention.

Hereinafter, a design method of a heat dissipation device according to an embodiment of the present invention (also referred to as a 'heat dissipation design method for an active antenna') will be described with reference to FIGS. 1 to 23.

In the method of designing a heat dissipation device according to an embodiment of the present invention, a process of determining a design target, shape designing a plate portion for heat source heat dissipation, numerically analyzing the performance of the shape-designed plate portion, and determining the shape of the plate portion according to the result The preliminary design process, the shape design of the header for cooling fluid circulation, numerical analysis of the performance of the shape-designed header, and the optimization design process to determine the shape of the header according to the result, and the performance of the shaped plate and header Includes a process of numerical analysis and thermal analysis to compare the results with design goals.

Determine design goals. Specifically, the thermal requirements for smooth performance of the active antenna 1 are determined as design goals.

In the case of the liquid cooling method, since the heat dissipation temperature of the heat generating source is sensitively reacted according to physical characteristics such as temperature and flow rate of the cooling fluid, the thermal requirements must be correct.

Examples of thermal requirements are listed in Table 1 below.

Requirements Remarks Max. Temp. <T ℃ Max. Temp. of Chips ΔT <ΔT ℃ Max. Temp. － Min. Temp. Temperature distribution Shape Negative Parabola

Referring to Table 1, the condition in which the temperature of the transmitting and receiving elements 21 is lower than the reference temperature, the condition in which the temperature deviation of the transmitting and receiving elements 21 is lower than the reference temperature deviation, and the temperature distribution of the transmitting and receiving elements 21 are in a negative parabolic shape. Determining matching conditions is a design goal.

The heat dissipation device 300 is designed to satisfy these thermal requirements.

The reference temperature means the highest temperature among the temperatures of the transmitting and receiving elements 21 capable of operating normally. The reference temperature is also called the required temperature. The reference temperature deviation means a deviation between the highest temperature and the lowest temperature among the temperatures of the transmitting and receiving elements 21 capable of normal operation. The reference temperature range is also referred to as a required temperature range.

In the temperature distribution, the order of the plurality of plate parts 310 is the horizontal axis, and the temperature of the selected main elements among the plurality of transmitting / receiving elements 21 in each plate part 310 is the vertical axis, and the two-dimensional graph When shown, it means the shape of the graph.

That is, the shape of the graph when the temperature of the selected main elements among the plurality of transmitting and receiving elements 21 is shown in a two-dimensional graph along the direction in which the plate portion 310 is listed is the temperature distribution.

The negative parabolic shape means that the shape of the graph is generally symmetrical from side to side, its central portion is convex upward, and its peripheral portion is convex downward.

Then, the shape of the plate portion for heat dissipation is designed, the performance of the shape-designed plate portion is numerically analyzed, and the shape of the plate portion is determined according to the result.

The active antenna 1 may be arranged in a transmission / reception module 20 to suit a predetermined task. Based on the arrangement of the predetermined transmission / reception module 20, the shape of the plate portion 310 is designed. For example, the plate portion 310 is designed into a rectangular plate shape having a thickness of several tens of mm, a width of several hundred mm, and a length of several meters.

In addition, when the arrangement of the transmission / reception module 20 is predetermined, and the shape of the outer shape of the plate portion 310 is designed, the heating temperature of the transmission / reception module 20 in thermal contact with the plate portion 310 and the plate portion 310 radiate heat. It is possible to know the amount of heat to be performed and the flow rate of the cooling fluid required for heat dissipation. The flow path of the plate part 310 is designed based on the flow rate of the cooling fluid required for the arrangement and heat dissipation of the transmission / reception module 20. For example, various shapes of flow paths having a predetermined flow cross-sectional area and passing through a plurality of rows are arranged along the arrangement pattern of the transmission / reception elements 21.

The performance of the shape-designed plate portion 310 is numerically analyzed. In this case, FLOW-3D v11, a 3D commercial computational fluid analysis code, may be used for numerical analysis. In the numerical analysis, the thermal and pressure characteristics of the plate portion 310 can be analyzed. At this time, the following analysis conditions are used.

7 is a view showing a heat dissipation path. The heat dissipation path between the transceiver element 21 and the plate portion 310 includes a circuit board 23, a thermally conductive grease (not shown), a high power amplifier board carrier (24), a thermally conductive grease (not shown), and It may be formed of a housing 22.

The total heat resistance of the heat dissipation path can be obtained by summing the heat resistance of each of the circuit board 23, the thermally conductive grease, the high power amplifier board carrier (24), the thermally conductive grease, and the housing 22.

At this time, the thermal resistance of the thermally conductive grease is inversely proportional to the thermal conductivity of the thermally conductive grease and the area to which the thermally conductive grease is applied, and is proportional to the thickness of the thermally conductive grease.

On the other hand, the contact heat resistance between the housing 22 and the plate portion 310 is inversely proportional to the heat transfer coefficient and the contact area, and is proportional to the contact surface gap (thickness). At this time, it can be assumed that the thermal resistance of the thermally conductive grease has a smaller value than the contact thermal resistance between the housing 22 and the plate portion 310.

For accurate numerical analysis, the contact heat resistance was experimentally derived by reflecting the roughness and the contact pressure of the contact surface between the housing 22 and the plate portion 310.

The total thermal resistance of the heat dissipation path is obtained in the manner described above and used for numerical analysis.

FIG. 8 (a) is a diagram showing a part of a transmission / reception module of a computational fluid dynamics model (hereinafter referred to as a “model”) for numerical analysis, and FIG. 8 (b) shows a part of the flow path of the model as an example. 8 (c) is a view showing a part of the plate portion of the model by way of example. In the drawings, the grid of the model is omitted.

The computational fluid dynamics model for numerical analysis is modeled as in (a), (b) and (c) of FIG. 8. At this time, in order to confirm the number of lattices suitable for numerical analysis, the model was thermally analyzed while changing the number of lattices of the model, and the maximum temperature of the resulting model was illustrated graphically as shown in FIG. 9.

Referring to FIG. 9, the results of thermal analysis converge to a constant value in a grid number of 7 million or more. Accordingly, in the embodiment of the present invention, modeling and numerical analysis are performed using 8 million hexagonal grids.

10 is a view showing boundary conditions to be used for numerical analysis. Numerical analysis uses normal analysis, and turbulence model uses κ-ε model. The κ-ε model is widely used in commercial heat transfer analysis fields with relatively accurate analysis results and fast calculation speed.

In an embodiment of the present invention, a comparatively accurate analysis result in a wide three-dimensional analysis domain, various case analysis, and a turbulence model suitable for excellent convergence are selected to perform analysis.

11 is a view showing a flow path shape used in numerical analysis. 2Row is a two-column branch, 3Row is a three-column branch, and S is an S-type single channel. In cases 4 and 5, a value of 15 mm indicates a position change. Numerical analysis is performed with the same boundary conditions other than the flow path shape. At this time, the influence of the type of cooling fluid and the change in the position of the flow path is examined. Here, the types of cooling fluid used in the numerical analysis are two types of EGW 60% solution and PAO.

12 to 15 are diagrams showing the results of the numerical analysis described above.

12 is a view exemplarily showing the temperature distribution of the transmitting and receiving elements 21 on the plate portion 310. 13 and 14 are graphs showing the temperature difference between the highest temperature, the highest temperature, and the lowest temperature among the temperatures of the transmitting and receiving elements 21 on the plate portion 310 according to the type, flow path type, and location of the cooling fluid, respectively. It is one drawing.

FIG. 14 is a graph illustrating pressure loss of a flow path according to a type of cooling fluid, a flow path shape, and a position.

Looking at the thermal characteristics and pressure characteristics of the plate portion 310 derived from the numerical analysis, first, the single channel has the largest pressure loss. However, despite the pressure loss, the heat dissipation performance is best for the S-type single channel. And it can be seen that the type of cooling fluid is superior to PAO in EGW 60% solution with high specific heat. In addition, it can be seen that the change in the position of the cooling passage does not significantly affect the heat dissipation performance.

Accordingly, the shape of the plate portion 310 determines that a single plate having a thickness of several tens of millimeters, a width of several hundred mm, and a length of several meters, and an S-shaped single channel having a predetermined flow cross-section is formed therein.

Thereafter, the header portion for cooling fluid circulation is shape-designed, the performance of the shape-designed header portion is numerically analyzed, and the shape of the header portion is determined according to the result.

Since the temperature distribution of the transmitting / receiving element 21 and the temperature distribution of the transmitting / receiving element 21 in the direction in which the plate portion 310 is listed directly affects the performance of the active antenna 1, the cooling fluid to the plate portion 310 Flow distribution is important.

The flow resistance of the plate portion 310 for flow distribution analysis is analyzed by three-dimensional computational fluid dynamics, and one-dimensional analysis is applied to the flow path system analysis. For the one-dimensional analysis, FLOW MASTER v8, a commercial computational fluid analysis code, is used.

16 is an analysis model for one-dimensional analysis. Reference numeral 41 is an analysis element representing pressure loss due to the shape and flow rate distribution of the inlet header portion, and reference numeral 42 is an analysis element representing pressure loss of the cooling fluid due to friction and flow resistance while passing through a single flow path of the plate portion. Reference numeral 43 is an analysis element indicating pressure loss due to confluence of flow at the outlet header. The flow resistance in the plate section is analyzed by applying the 3D analysis results.

The flow rate of the cooling fluid flowing into the plate portion is determined by the inlet and outlet pressure of a single flow path of the plate portion. In order to determine the shape of the header portion capable of uniformly distributing the flow rate in consideration of the inlet and outlet pressures of the single flow path of the plate portion, the header portion is designed in four ways shown in FIG. 17. D in the drawing refers to a reference cross-sectional area, basic design and case 1 correspond to comparative examples of the present invention, case 2 and case 3 correspond to embodiments of the present invention. In the shape design, the design factor is the cross-sectional area of the header. The cross-sectional area of the header portion is different from that of the minimum cross-sectional area of 0.8D to 1.6D, based on the value D of the reference cross-sectional area described above.

The objective function for determining the shape of the header is as shown in [Equation 1] below.

[Equation 1]

는 입구 헤더부(320)를 통하여 복수개의 플레이트부(310)로 공급되는 냉각유체의 총 유량을 플레이트부(310)의 개수로 나눈 평균 유량이다.Here, Φ is a value indicating the degree of flow distribution, N is the number of the plate portion 310, i is the order of the plate portion 310, Q is the flow rate of the cooling fluid,

Is an average flow rate obtained by dividing the total flow rate of the cooling fluid supplied to the plurality of plate parts 310 through the inlet header part 320 by the number of plate parts 310.

Here, the closer the value of the objective function is to 0, the more uniform the flow distribution is.

18 is a result of numerical analysis of a model of comparative examples and examples of the present invention, the horizontal side represents the order of the plate portion, and the vertical side represents the flow rate.

18, it can be seen that in the case of the comparative examples, the flow rate is linearly changed according to the order of the plate portion. In this case, since the temperature of the transmitting / receiving element also varies linearly according to the order of the plate portion, a large error in the beam emission angle of the active antenna 1 may be caused.

On the other hand, in the case of the embodiments, it can be seen that the difference between the flow rate of the first plate portion and the flow rate of the last plate portion is greatly narrowed. That is, it can be seen that the flow distribution is relatively uniform. Based on the results of the analysis, in the embodiment of the present invention, the shape of the header is determined as Case 2 and Case 3 shown in FIG. 17.

Thereafter, the performance of the plate portion and the header portion having the shape determined is numerically analyzed, and the result is compared with a design target.

19 and 20 are diagrams showing a numerical analysis model for performing thermal analysis of an active antenna to which a shape plate and a header portion are applied.

Numerical analysis is performed using the model shape derived from the above-described series of processes and the analysis conditions such as the optimized flow rate conditions in the above-described series of processes, and the results are compared to the design goals to be active. Check the thermal performance of the antenna. The computational grid used for the numerical analysis is a hexagonal alignment grid and the number is about 53.5 million.

21 is a result of numerical analysis using model shape and analysis conditions according to comparative examples. Rows 1 to 7 of FIG. 21 respectively indicate a main element selected from the transmitting and receiving elements. Referring to FIG. 21, it can be seen that the temperature of the main elements linearly changes according to the order of the plate portions expressed on the horizontal sides. This is because the header portion structure of the comparative example does not uniformly distribute the cooling fluid to each plate portion.

That is, in the comparative example, the temperature distribution of the main elements does not form a negative parabolic shape, but forms a linear growth shape. Accordingly, the error between the desired beam emission angle of the active antenna 1 and the actual beam emission angle can be greatly increased.

On the other hand, Figure 22 is a result of numerical analysis using the model shape and analysis conditions according to the embodiments. Rows 1 to 7 of FIG. 22 respectively indicate a main element selected from the transmitting and receiving elements. 22, it can be seen that the temperature distribution forms a negative parabolic shape. From this, it can be seen that in the header portion structure of the embodiment of the present invention, the cooling fluid is distributed as uniformly as possible in each plate portion. In this case, an error between a desired beam emission angle of the active antenna 1 and an actual beam emission angle can be minimized.

23 is a diagram showing the results of the numerical analysis described above in a table in comparison with the design goals. In Fig. 23, the initial design shows a comparative example, and the final design shows an example. 23, the comparative example satisfies the condition in which the temperature of the transmitting and receiving elements 21 is lower than the reference temperature, and the condition in which the temperature deviation of the transmitting and receiving elements 21 is lower than the reference temperature deviation, but the temperature distribution of the transmitting and receiving elements 21 is It can be seen that it does not conform to the negative parabolic shape. On the other hand, in the embodiment, the conditions of the temperature of the transmitting and receiving elements 21 are lower than the reference temperature, the conditions of the temperature deviation of the transmitting and receiving elements 21 are lower than the reference temperature deviation, and the temperature distribution of the transmitting and receiving elements 21 conforms to the negative parabolic shape. It can be seen that all the conditions described above are satisfied.

As described above, according to an embodiment of the present invention, considering the requirements for the normal operation of the active antenna 1, each header portion and the plate portion are designed, and the suitability of the design results can be confirmed through numerical analysis. . In addition, a liquid cooling type heat dissipation device 300 for dissipating heat of the transmitting / receiving element by circulating the cooling fluid through a single flow path of the cooling plate in the header part whose shape is improved by reflecting the design result having confirmed conformity may be provided. In addition, the thermal reliability of the active antenna 1 may be increased by using the heat dissipation device 300, and stable mission performance may be performed.

The above embodiments of the present invention are for the purpose of describing the present invention and not for the limitation of the present invention. It should be noted that the configurations and methods disclosed in the above embodiments of the present invention may be modified in various forms by combining or crossing each other, and such modified examples can be seen as the scope of the present invention. That is, the present invention will be implemented in a variety of different forms within the scope of the claims and equivalent technical spirit, and various embodiments are possible within the scope of the technical spirit of the present invention. Will be able to understand.

10: radiation element
20: sending and receiving module
21: transceiver element
22: housing
300: heat dissipation device
310: plate portion
320: entrance header
330: exit header
340: cooling fluid circulation unit
Du: upstream section
Dd: downstream section

Claims (12)

As a heat dissipation device of a free space active antenna with a single flow path,
A plurality of plate parts arranged in the first direction, extending in the second direction, and in thermal contact with the transmitting and receiving elements of the active antenna;
An inlet header portion extending in the first direction and communicating with one end of the plate portion;
An outlet header portion extending in the first direction and communicating with the other end portion of the plate portion;
Includes; through the inlet header portion and the outlet header portion, a cooling fluid circulation unit for supplying cooling fluid to the plate portion, and recovering the cooling fluid from the plate portion
Based on the flow of cooling fluid,
The inlet header portion has a cross-sectional area of the upstream section smaller than that of the downstream section, and the outlet header portion has a cross-sectional area of the upstream section larger than that of the downstream section,
When the size of the reference cross-sectional area of the inlet header part and the outlet header part is D, the cross-sectional area of the upstream section is equal to D, and the cross-sectional area of the downstream section is greater than D,
A single flow path extending and refracting a plurality of times in the second direction and the third direction is formed in the plate portion,
The transmitting and receiving elements are disposed on both sides of the plate portion in the first direction,
The transmitting / receiving elements are arranged in a lattice form on both sides, respectively, and a heat dissipation device of a free space active antenna provided with a single flow path. The method according to claim 1,
Assuming that the cross-sectional areas of the inlet header portion and the outlet header portion are constant in the first direction, if the flow rate value of the cooling fluid flowing therein is closest to the intermediate value, the plate portion is the reference plate,
The upstream section and the downstream section are defined with reference to the reference plate, a heat dissipation device of a free space active antenna with a single flow path. The method according to claim 2,
The reference plate is in communication with the upstream section, and the reference plate is a heat dissipation device of a free space active antenna equipped with a single flow path through which the cooling fluid is introduced and discharged through the upstream section. The method according to claim 1,
The lattice shape is a two-dimensional lattice shape for the second direction and the third direction,
A heat dissipation device of a free space active antenna equipped with a single flow path, wherein a single flow path is formed inside the plate portion along the grid shape. The method according to claim 1,
The inlet header portion and the outlet header portion are spaced apart in the second direction,
The plate portion between the inlet header portion and the outlet header portion, connecting the inlet header portion and the outlet header portion in a second direction, a heat dissipation device of a free space active antenna having a single flow path. The method according to claim 5,
With respect to the first direction, the flow of cooling fluid in the inlet header portion and the flow of cooling fluid in the outlet header portion are formed in the same direction. The method according to claim 1,
The plate portion, the length of the second direction is greater than the width in the third direction, the width of the third direction is greater than the thickness in the first direction, the heat sink of the free space active antenna provided with a single flow path. The method according to claim 7,
Each of the inlet header portion and the outlet header portion, the length of the first direction is greater than the diameter of the second and third directions, a free space active antenna heat dissipation device with a single flow path. The method according to claim 8,
The diameter of the inlet header portion and the outlet header portion is smaller than the width of the plate portion, greater than the thickness of the plate portion, a heat dissipation device of a free space active antenna with a single flow path. The method according to claim 1,
The single flow path includes at least three or more extension sections and at least two or more refraction sections, the number of extension sections increases oddly, the number of refraction sections increases evenly, and the flow cross section has a rectangular shape. Including, heat dissipation device of a free space active antenna equipped with a single flow path. The method according to claim 1,
The size of the cross-sectional area of the downstream section is 1.6D, a heat dissipation device of a free space active antenna equipped with a single flow path. A plurality of radiating elements for transmitting and receiving electromagnetic waves;
A plurality of transmission / reception elements for controlling the magnitude and phase of the electromagnetic wave fed to the radiation element;
An active antenna comprising a; heat dissipation device according to claim 1 in thermal contact with the transceiver element.

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