• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
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    • 专利摘要:
    Summary: The present invention relates to a controllable ratchet layer for electromagnetic straining, usable e.g. as a radom for example a radar antenna. The spar layer comprises a first frequency selective layer (4) of a certain geometric design, which frequency selective layer transmits straining of a certain polarization within a desired frequency range and reflects straining of another polarization and straining outside said range and at least a second similar frequency selective in connection to the first layer in the beam direction. The layers are designed to be placed in a first layer in relation to each other, so that together they have similar transmission properties as the first layer alone and in a second layer in relation to each other, so that together they reflect straining of said certain polarization within said desired frequency range.
    公开号:SE0600409A1
    申请号:SE0600409
    申请日:2006-02-23
    公开日:2015-07-15
    发明作者:Anders Grop
    申请人:Försvarets Materielverk；
    IPC主号:
    专利说明:

    Summary: The present invention relates to a controllable ratchet layer for electromagnetic straining, usable e.g. as a radom for example a radar antenna. The spar layer comprises a first frequency selective layer (4) of a certain geometric design, which frequency selective layer transmits straining of a certain polarization within a desired frequency range and reflects straining of another polarization and straining outside said range and at least a second similar frequency selective in connection to the first layer in the beam direction. The layers are designed to be placed in a first layer in relation to each other, so that together they have similar transmission properties as the first layer alone and in a second layer in relation to each other, so that together they reflect straining of said certain polarization within said desired frequency range. ink. The present invention relates to a controllable chimney layer for electromagnetic radiation, usable i.a. as a radom for, for example, a radar antenna.
    Radomers are normally used to provide physical and environmental protection for equipment, such as microwave antennas. At the same time, it is advantageous to shield such equipment from incident electromagnetic straining which can adversely affect its function and also often results in strong reflections in the equipment, which results in a higher radar painting area.
    An edge set to delimit straining outside the operating frequencies of an antenna is often to provide the radome with a so-called Frequency Selective Surface (FSS) layer. An FSS radome normally comprises one or more electromagnetically transparent materials, possibly with different dielectric constants. Furthermore, there are normally one or more electrically conductive layers that are sampled and exhibit team pass, hog pass or band pass filter characteristics and reflect incoming straining outside the radar's own working area. The reflection and transmission properties are controlled i.a. of the monster's formation. These can be etched from a thin copper layer laid on dielectric material.
    The conductive layer or layers are transparent for straining a certain polarization at the operating frequencies of the antenna, but reflective for straining another polarization (and, as stated above, for straining outside this frequency range). The transition between transmission and reflection is, of course, not stepwise, either in terms of frequency or polarization, but takes place gradually. FSS technology is the choice for professionals in the field. The less knowledgeable can take part in the technique, for example in the book "Frequency selective surfaces, Theory and design" by Ben A. Munk, ISBN 0-47137047-9, to which he is referred. Within the range of an antenna's operating frequencies, where an FSS radom transmits incident straining, an antenna often produces strong reflections, which is not Black from a radar malyte point of view. It would be better if all incident radiation is reflected in a controlled way in the radome, at least when the own radar does not transmit or receive radiation. nk t Want. odh Roolatreringaverket 111- 2 3 2 Fors & has been carried out to control a radom surface in different ways so that it transmits straining in the area of the antenna's operating frequencies only when the antenna is working and in between straining also reflects in this area. U.S. Patent 4,684,954 discusses such a proposal based on electrical switches in components of the radome layer. Different kanda row solutions all have different disadvantages.
    The present invention provides a quick solution to the present problem, which obviates many of the previous disadvantages. The invention has the object in that it is carried out in the manner set forth in the following independent patent claim.
    Other claims relate to advantageous embodiments of the invention.
    The invention will be described in more detail below with reference to the accompanying drawing, in which Fig. 1 shows a cross section of an embodiment of a controllable radiation barrier layer according to the invention and Fig. 2 shows an example of an edge FSS layer which can be used in the invention.
    The present invention operates with at least two FSS layers and a purely mechanical shutter function. The basic idea is to create a radiation barrier layer by using two, or more, FSS layers in layers in the radiation direction and mechanically move them in relation to each other. In a first age, with the layers adapted to each other, they together acquire similar transmission properties that a layer exhibits alone, which means that they transmit straining of a certain polarization around the operating frequencies of the antenna or corresponding equipment. In a second layer, the samples of the FSS layers are adapted for reflection of all straining. The transmission and reflection naturally change gradually at the Transition from the first team to the second team.
    The movement in the case of flat layers can take place by translation in the plane of the layers or rotation around the normal of the layers or a combination thereof. Even if the layers are curved rotationally symmetrical layers, the rotation can take place around the axis of rotation of the layers. If the layers are one-dimensionally curved, the pre-displacement can take place by means of a translation in the plane of the layers perpendicular to the plane of hooking.
    Ink. 233 If the asparagus layer is more or less flat, it can be placed within other ordinary transmitting radoms by other shells, for example aerodynamic views.
    In a studied example, the spar layer was flat and dimensioned to be transparent around the center frequency 10 GHz for vertically polarized straining in the first layer. The antenna behind was intended to illuminate the ridge layer with normal incidence and vertical polarization. The spar layer was assumed to be exposed to enemy lighting at the elevation angle in relation to the normal of the spar layer. The threat band was assumed to be 2-20 GHz. The spar layer would in the rod layer be reflective for all polarizations having the incident signal. In the open layer, the spar layer should be reflective of cross-polarization relative to the polarization of the own sensor, ie. for horizontal polarization.
    These assumptions led to a build-up on the ridge layer shown in Figure 1.
    The spar layer was designed as two flat polarization layers which could be rotated in relation to each other and which were of a so-called half-way design, ie. had a total thickness of the ridge layer / radom wall corresponding to half the wavelength at the frequency for which it is adapted. Such a layer should be about 7 mm thick at 10 GHz. In the present case, the spar layer consisted of two glass composite layers 1 of 2.8 mm each with FSS carrier 2 with glue 3 glued to the facing surfaces of the glass fiber composite layers. The FSS layers 4 were made of copper and mounted against the respective glass fiber composite layers 1 so that its carriers 2 protected them from damage during rotation. The thickness of the FSS layers with bare was 0.35 mm. Intermediate air gap 5 halls as thin as possible.
    In the example studied, an FSS pattern was chosen in the form of linear dipoles. Such a layer is reflective for signals that are polarized parallel to the dipoles and transparent for signals that are polarized perpendicular to the dipoles. To obtain bandwidth, the dipoles were extremely packed in a Gangbuster type 4 grid, see Figure 2. In the example, the dipoles were 6, 12 mm long and had a width of 0.3 mm. The periodicity was about 3 mm.
    Calculations showed that the desired savings effect was achieved. As soon as the layers were rotated from the first layer with parallel dipoles in the two layers, the transmission through the layers decreased and at ± 900 + n.180 ° the combined Ink reflected. t patent- a * RegletrerIngsverket 20116 V- 2 34 sparr layer at most. Depending on the flatness or cracking of the spar layer and the design of the straw sample, the desired spar effect in other examples can be obtained for other angles of rotation.
    Since there are two or more parts that are to be moved in relation to each other, special consideration must be given to the spruce surface or spruce surfaces that arise. If the two parts are allowed to mechanically touch each other, care must be taken to mechanically protect the FSS layer. In addition, the FSS layers are not affected by electrical shells.
    You can of course have air in the gap between the bath parts, but in some applications a watery batter is better. The liquid should have a dielectric constant that is adapted to the dielectric constant in the adjacent materials.
    It is important that dimensional changes do not occur in the two parts and the gap, as these can cause transmission losses / distortions, even when the own antenna transmits through the ridge layer / radome, as when the ridge layer is reflective, it receives all straining. The main requirement is that Walla has the right distance (minimal dimensional change) between the parts when sanding or receiving. Care must be taken to ensure that the layers are not pooped when the radome has been exposed to the outer surface.
    If you use air, or other gas, or liquid between the layers, you can minimize the gap and thereby create stability for the ridge layer, by sucking gas or liquid out of the gap with negative pressure. The gap can then, in order to avoid wear and tear, & as something before a movement of the two layers in relation to each other.
    By letting liquid or gas circulate through the gap, you can create an active cooling that can sink and control the temperature of the chevron layer, which reduces and controls the thermal signature. You can then regulate by changes in the temperature or flow rate of the flowing medium or bathing. Columns should in this case be laid close to the FSS layers, since heat generation for the most part takes place there.
    权利要求:
    Claims (4)
    [1]
    A controllable ratchet layer for electromagnetic straining, comprising a first frequency selective layer (4) of a certain geometric design, which frequency selective layer transmits straining of a certain polarization within a desired frequency range and reflects straining of another polarization and straining outside said range! that it comprises at least a second similar frequency-selective layer, of said certain geometric design, which is placed adjacent to the first layer in the beam direction, that the layers are designed to be placed in a first layer in relation to each other, so that together they have similar transmission properties as the first layer alone and that the layers are formed can be placed in a second position in relation to each other, so that together they reflect straining of said certain polarization within said desired frequency range.
    [2]
    Controllable ratchet layer according to claim 1, characterized in that the frequency-selective layers are surfaces of rotation, or in a special case flat, and the relative movement between the first layer and the second layer takes place by rotation of one or more layers around the axis of symmetry of the surfaces of rotation or in the flat case the normal of the layers.
    [3]
    Controllable ratchet layer according to claim 1, characterized in that the frequency selective layers are one-dimensionally curved, or in a special case flat, and the relative movement between the first layer and the second layer takes place by translating one or both layers in the plane of the layers, in the curved case perpendicular to the plane of curvature.
    [4]
    Controllable ratchet layer according to any one of the preceding claims, characterized in that a gas or a liquid is passed between said first frequency selective layer and said at least one second frequency selective layer and that the thermal signature of the ratchet layer is controlled by means of temperature changes in the gas or liquid and / or changes in their velocity. patent.ach Twoffermosverhot MN 12. 2 3 LOCN mm; .. °° 0 • 000.1 Width 0.3 mm Length 12 mm
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    同族专利:
    公开号 | 公开日
    SE537881C2|2015-11-10|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    2018-10-02| NUG| Patent has lapsed|
    优先权:
    申请号 | 申请日 | 专利标题
    SE0600409A|SE537881C2|2006-02-23|2006-02-23|Controllable barrier layer for electromagnetic radiation|SE0600409A| SE537881C2|2006-02-23|2006-02-23|Controllable barrier layer for electromagnetic radiation|
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