Patent Publication Number: US-2023155294-A1

Title: Antenna and communication apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a National Phase Application filed under 35 U.S.C. 371 as a national stage of PCT/CN2021/074275 filed on Jan. 29, 2021, the content of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the field of communication technology, and in particular, to an antenna and a communication apparatus. 
     BACKGROUND 
     A radial line slot antenna has the advantages of small loss of a waveguide slot array, simple structure of a microstrip antenna, and low profile, and thus, is widely applied to millimeter wave microwave systems. Generally, the radial line slot antenna is composed of an upper metal plate and a lower metal plate that have therebetween a distance less than ½ wavelengths, to form a radial waveguide, and designed slots are formed in the upper metal plate, so that any polarization mode or radiation characteristic can be realized. 
     SUMMARY 
     Embodiments of the present disclosure provide an antenna and a communication apparatus. 
     In a first aspect, embodiments of the present disclosure provide an antenna, which includes: 
     a dielectric layer having a first surface and a second surface opposite to each other in a thickness direction of the dielectric layer; 
     a radiating layer on the first surface of the dielectric layer, and having therein at least one slit; 
     a first shielding layer on the second surface of the dielectric layer, and being electrically connected to the radiating layer; 
     wherein the antenna further includes: 
     a first insulating layer on a side of the radiating layer distal to the first surface of the dielectric layer; 
     at least one switch unit on a side of the first insulating layer distal to the dielectric layer, and being in one-to-one correspondence with the at least one slit; and 
     each switch unit includes: a first electrode, a second insulating layer, at least one connecting portion, and a second electrode that are sequentially arranged in a direction away from the first insulating layer, wherein an orthogonal projection of the first electrode on the dielectric layer and an orthogonal projection of the second electrode on the dielectric layer overlap each other, the at least one connecting portion is connected to the second electrode to form a certain gap between the second electrode and the first electrode, and the orthogonal projection of the second electrode on the dielectric layer and an orthogonal projection of a corresponding slit on the dielectric layer at least partially overlap each other. 
     In an embodiment, the orthogonal projection of the second electrode on the dielectric layer covers a center of the orthogonal projection of the corresponding slit on the dielectric layer. 
     In an embodiment, the first electrode includes a first sub-electrode and a second sub-electrode, and orthogonal projections of the first sub-electrode and the second sub-electrode on the dielectric layer are respectively on both sides, which are along a lengthwise direction of the orthogonal projection of the corresponding slit on the dielectric layer, of the orthogonal projection of the corresponding slit on the dielectric layer, and the at least one connecting portion is on a portion of the second insulating layer on at least one of the first sub-electrode and the second sub-electrode of each switch unit. 
     In an embodiment, each switch unit includes two connecting portions, the two connecting portions are respectively connected to two opposite ends of the second electrode in a lengthwise direction of the second electrode, and the lengthwise direction of the second electrode in each switch unit intersects with a lengthwise direction of the slit corresponding to the switch unit. 
     In an embodiment, each switch unit includes one connecting portion connected to one end of the second electrode in a lengthwise direction of the second electrode, and the lengthwise direction of the second electrode in each switch unit intersects with a lengthwise direction of the slit corresponding to the switch unit. 
     In an embodiment, the dielectric layer includes a first sub-dielectric layer and a second sub-dielectric layer, a surface of the first sub-dielectric layer distal to the second sub-dielectric layer serves as the first surface of the dielectric layer, a surface of the second sub-dielectric layer distal to the first sub-dielectric layer serves as the second surface of the dielectric layer, the antenna further includes a second shielding layer between the first sub-dielectric layer and the second sub-dielectric layer, and an edge of an orthogonal projection of the second shielding layer on the first sub-dielectric layer and a corresponding edge of an orthogonal projection of the first shielding layer on the first sub-dielectric layer have a certain distance therebetween. 
     In an embodiment, an orthogonal projection of a center of the first shielding layer on the first sub-dielectric layer and an orthogonal projection of a center of the second shielding layer on the first sub-dielectric layer overlap each other. 
     In an embodiment, the at least one slit includes a plurality of slits, and the plurality of slits are arranged to form one of the following: 
     a spiral shape; 
     concentric circles; and 
     a linear shape. 
     In an embodiment, the antenna further includes a feeding element for feeding an electromagnetic wave signal into the dielectric layer, and a feeding point of the feeding element is at a center of the radiating layer. 
     In an embodiment, the dielectric layer includes a material of glass. 
     In a second aspect, embodiments of the present disclosure provide a communication apparatus, which includes the antenna according to any one of the foregoing embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram showing an antenna according to an embodiment of the present disclosure. 
         FIG.  2    is a top view of the antenna shown in  FIG.  1   . 
         FIG.  3    is a schematic diagram showing a turn-on state of a switch unit according to an embodiment of the present disclosure. 
         FIG.  4    is a schematic diagram showing a turn-off state of a switch unit according to an embodiment of the present disclosure. 
         FIG.  5    is a schematic diagram showing a turn-on state of another switch unit according to an embodiment of the present disclosure. 
         FIG.  6    is a schematic diagram showing a turn-off state of another switch unit according to an embodiment of the present disclosure. 
         FIG.  7    is a schematic diagram showing another antenna according to an embodiment of the present disclosure. 
         FIG.  8    is a schematic diagram showing a simulation of a switch unit of the antenna shown in each of  FIGS.  1  to  7   . 
         FIG.  9    is a top view showing another antenna according to an embodiment of the present disclosure. 
         FIG.  10    is a side view of the antenna shown in  FIG.  9   . 
     
    
    
     DETAILED DESCRIPTION 
     To enable one or ordinary skill in the art to better understand technical solutions of the present disclosure, the present disclosure will be further described in detail below with reference to the accompanying drawings and exemplary embodiments. 
     Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which the present disclosure belongs. The terms “first”, “second”, and the like used in the present disclosure are not intended to indicate any order, quantity, or importance, but rather are used for distinguishing one element from another. Further, the term “a”, “an”, “the”, or the like used herein does not denote a limitation of quantity, but rather denotes the presence of at least one element. The term of “comprising”, “including”, or the like, means that the element or item preceding the term contains the element or item listed after the term and its equivalent, but does not exclude other elements or items. The term “connected”, “coupled”, or the like is not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect connections. The terms “upper”, “lower”, “left”, “right”, and the like are used only for indicating relative positional relationships, and when the absolute position of an object being described is changed, the relative positional relationships may also be changed accordingly. 
     It should be noted that a structure of an antenna according to an embodiment of the present disclosure includes, but is not limited to, a cylinder, a rectangular parallelepiped, a cube, or the like. In the following description of an embodiment, the structure of a slot antenna is exemplified as a cylinder. In an embodiment of the present disclosure, a material of a dielectric layer of the slot antenna includes, but is not limited to, glass, i.e., the dielectric layer may be made of glass. In fact, the material of the dielectric layer may alternatively be any insulating material capable of forming a structure with a flat surface, such as quartz, polyimide, transparent optical adhesive, or the like. Further, a dielectric constant of the dielectric layer is not limited, and an adopted thickness of the dielectric layer depends on the dielectric constant and an operating frequency of the antenna. In the following embodiments, description will be made by taking an example in which the dielectric layer is a glass dielectric layer, but this is not intended to limit the scope of the embodiments of the present disclosure. 
     In a first aspect, an embodiment of the present disclosure provides an antenna, and  FIG.  1    is a schematic diagram showing the antenna according to the present embodiment.  FIG.  2    is a top view of the antenna shown in  FIG.  1   .  FIG.  3    is a schematic diagram showing a turn-on state of a switch unit  60  according to the present embodiment, and  FIG.  4    is a schematic diagram showing a turn-off state of the switch unit  60  according to the present embodiment. As shown in  FIGS.  1  to  4   , the antenna includes a dielectric layer  10 , a first shielding layer  30 , a radiating layer  20 , a first insulating layer  61 , and at least one switch. The dielectric layer  10  includes a first surface and a second surface opposite to each other, the first surface being an upper surface of the dielectric layer  10  in  FIG.  1   , and the second surface being a lower surface of the dielectric layer  10  in  FIG.  1   . The radiating layer  20  is arranged on the first surface of the dielectric layer  10 , and is provided with at least one slit (or slot)  21  therein. The first shielding layer  30  is disposed on the second surface of the dielectric layer  10 , and is electrically connected to the radiating layer  20  disposed on the first surface of the dielectric layer  10 . One switch unit  60  in the present embodiment may be disposed corresponding to one slit  21 , and for example, switch units  60  are disposed to be in one-to-one correspondence with slits  21 . Each switch unit  60  may include a first electrode, a second insulating layer  63 , at least one connecting portion  64 , and a second electrode  65 , which are sequentially disposed along a direction away from the first insulating layer  61 . For example, an orthogonal projection of the first electrode on the dielectric layer  10  and an orthogonal projection of the second electrode  65  on the dielectric layer  10  overlap each other. Each connecting portion  64  is connected to the second electrode  65  such that a certain gap (or distance) exists between the second electrode  65  and the first electrode. An orthogonal projection of the second electrode  65  on the dielectric layer  10  at least partially overlaps an orthogonal projection of a corresponding slit  21  on the dielectric layer  10 . Optionally, the antenna including slits  21  (i.e., slot antenna) further includes a feeding element  50  and the like, and the feeding element  50  is for feeding an electromagnetic wave into the dielectric layer  10  through the first shielding layer  30 . 
     It should be noted that, the first shielding layer  30  and the radiating layer  20  may be electrically connected to each other through a through hole  40  penetrating through an edge region of the dielectric layer  10 . The number of through holes  40  may be two or more, and the two or more through holes  40  are spaced apart from each other. 
     Since one switch unit  60  is disposed on each slit  21  of the antenna according to the present embodiment, and a certain gap exists between the first electrode and the second electrode  65  of each switch unit  60 , when no voltage is applied across the first electrode and the second electrode  65 , the switch unit  60  is in a turn-on state as shown in  FIG.  3   , and a microwave signal fed into the dielectric layer by the feeding element  50  may be radiated out of the dielectric layer through the slit  21 . When a direct current (DC) bias voltage is applied across the first electrode and the second electrode  65 , the second electrode  65  is pulled down to a surface of the corresponding slit  21  under the action of static electricity, and at this time, the switch unit  60  is in a turn-off state as shown in  FIG.  4   . In this case, a microwave signal fed into the dielectric layer by the feeding element  50  cannot be radiated out of the dielectric layer, i.e., the switch serves as a shielding electrode. In addition, when the antenna includes a plurality of slits  21  and a plurality of switch units  60 , a direct current bias voltage may be selectively applied across the first electrodes and the second electrodes  65  of some of the switch units  60 , so that a microwave signal may be radiated out of the dielectric layer through some of the slits  21 , but cannot be radiated out of the dielectric layer through other of the slits  21 , thereby adjusting a radiation direction of the microwave signal. 
     In some examples, the orthogonal projection of the second electrode  65  of each switch unit  60  on the dielectric layer  10  covers a center of the orthogonal projection of the corresponding slit  21  on the dielectric layer  10 . 
     In this case, when a direct current bias voltage is applied across the first electrode and the second electrode  65  of each switch unit  60 , the second electrode  65  is driven by an electrostatic force to cover the slit  21  to shield a microwave signal. It should be noted that, in general, the orthogonal projection of the second electrode  65  on the dielectric layer  10  may not completely cover the orthogonal projection of the corresponding slit  21  on the dielectric layer  10 . A length of each slit  21  is generally much greater than a width of the corresponding second electrode  65 . 
     In order to make the structure of each switch unit  60  according to an embodiment of the present disclosure more clear, two specific structures of each switch unit  60  will be described below. 
     In an example, each switch unit  60  is a MEMS (micro-electro-mechanical system) switch, and the first electrode of each switch unit  60  includes a first sub-electrode  621  and a second sub-electrode  622 . Further, an orthogonal projection of the first sub-electrode  621  on the dielectric layer  10  and an orthogonal projection of the second sub-electrode  622  on the dielectric layer  10  are arranged on both sides of a lengthwise direction of the orthogonal projection of the corresponding slit  21  on the dielectric layer  10 , respectively. Each switch unit  60  includes two connecting portions  64 , which are respectively connected to two opposite ends of the corresponding second electrode  65  in a lengthwise direction of the corresponding second electrode  65 . Further, one of the two connecting portions  64  is located on a portion of the second insulating layer  63  on the first sub-electrode  621 , and the other of the two connecting portions  64  is located on a portion of the second insulating layer  63  on the second sub-electrode  622 . In addition, an orthogonal projection of each of the first sub-electrode  621  and the second sub-electrode  622  on the dielectric layer  10  overlaps the orthogonal projection of the corresponding second electrode  65  on the dielectric layer  10 . In some examples, the two connecting portions  64  and the corresponding second electrode  65  have a one-piece structure, and may be formed through a single patterning process. 
     In another example,  FIG.  5    is a schematic diagram showing a turn-on state of another switch unit  60  according to an embodiment of the present disclosure.  FIG.  6    is a schematic diagram showing a turn-off state of the another switch unit  60  according to an embodiment of the present disclosure. The switch unit  60  shown in  FIGS.  5  and  6    is substantially the same as that shown in  FIG.  3   , except that the switch unit  60  shown in  FIGS.  5  and  6    includes only one connecting portion  64 , and other structures thereof are the same as those of the switch unit  60  shown in  FIG.  3   , thus detailed description thereof being omitted here. 
     It should be noted that, for the switch unit  60  shown in  FIG.  5   , the second insulating layer  63  and the first electrode (which is, in particular, the second sub-electrode  622 ) may not be provided below an end, at which the connecting portion  64  is not provided, of the second electrode  65 . In this case, as long as a direct current bias voltage applied across the first sub-electrode  621  and the second electrode  65  is controlled so that the switch unit  60  may be in a turn-off state as shown in  FIG.  6   , the second electrode  65  may also be driven by an electrostatic force to be in contact with the corresponding slit  21  in the radiating layer  20 . 
     In some examples,  FIG.  7    is a schematic diagram showing another antenna according to an embodiment of the present disclosure. As shown in  FIG.  7   , a dielectric layer  10  of the antenna includes a first sub-dielectric layer  11  and a second sub-dielectric layer  12 , and the antenna including slits  21  further includes a second shielding layer  70  disposed between the first sub-dielectric layer  11  and the second sub-dielectric layer  12 . Further, an edge of an orthogonal projection of the second shielding layer  70  on the first sub-dielectric layer  11  and a corresponding edge of an orthogonal projection of the first shielding layer  30  on the first sub-dielectric layer  10  have a certain distance therebetween. For example, a surface of the first sub-dielectric layer  11  distal to the second sub-dielectric layer  12  serves as the first surface of the dielectric layer  10 , and a surface of the second sub-dielectric layer  12  distal to the first sub-dielectric layer  11  serves as the second surface of the dielectric layer  10 . The radiating layer  20  is formed on the surface of the second sub-dielectric layer  12  distal to the first sub-dielectric layer  11 , and the first shielding layer  30  is formed on the surface of the first sub-dielectric layer  11  distal to the second sub-dielectric layer  12 . The radiating layer  20  and the first shielding layer  30  are connected to each other through a through hole  40  penetrating through the first sub-dielectric layer  11  and the second sub-dielectric layer  12 . The second shielding layer  70  may be formed on a surface of the first sub-dielectric layer  11  proximal to the second sub-dielectric layer  12 , or on a surface of the second sub-dielectric layer  12  proximal to the first sub-dielectric layer  11 . The following description will be made by taking an example in which the second shielding layer  70  is formed on the surface of the first sub-dielectric layer  11  proximal to the second sub-dielectric layer  12 . Each through hole  40  in the first sub-dielectric layer  11  and the second sub-dielectric layer  12  may be formed as a TGV (e.g., through glass via), and may be metalized, i.e., a metal conductive layer may be formed on an inner wall of each through hole  40  or a metal may be filled in each through hole  40 . The radiating layer  20  and the second shielding layer  70  may be formed on upper and lower surfaces of the first sub-dielectric layer  11  by using an electroplating process, respectively, and slits  21  in the radiating layer  20  may be formed by a patterning process. The first shielding layer  30  may be formed on a lower surface of the second sub-dielectric layer  12  by an electroplating process, and the first sub-dielectric layer  11  and the second sub-dielectric layer  12  may be aligned and assembled into a cell by a VAS (e.g., vacuum aligning technology), so as to result in a double-layer feeding layer with an extremely high alignment accuracy. The thickness of the dielectric layer  10  depends on the operating frequency of the antenna including slits  21 , and the thickness of the dielectric layer  10  is selected to be smaller for a higher operating frequency of the antenna including slits  21 . That is, in an embodiment of the present disclosure, a thickness of each of the first sub-dielectric layer  11  and the second sub-dielectric layer  12  of the dielectric layer  10  may be designed according to an operating frequency of the antenna including slits  21 . In an embodiment of the present disclosure, each of the first sub-dielectric layer  11  and the second sub-dielectric layer  12  may be single-layer glass or multi-layer glass. 
     In the antenna including slits  21  with such a structure, there is no electrical connection between the second shielding layer  70  and any through hole  40 , and the second shielding layer  70  mainly serves as making an electromagnetic wave fed into the dielectric layer  10  be distributed uniformly. Specifically, an electromagnetic wave fed by the feeding element  50  enters into the first sub-dielectric layer  11 , propagates from a center line of the first sub-dielectric layer  11  along a radial direction of the antenna including slits  21 , and then propagates to the second sub-dielectric layer  12  from an edge of the second shielding layer  70 . That is, the electromagnetic wave propagates from a center to an edge of the first sub-dielectric layer  11 , propagates from an edge to a center of the second sub-dielectric layer  12 , and then is radiated out of the dielectric layer through the slits  21  in the radiating layer  20 . In this way, the transmission and radiation of the electromagnetic wave is more uniform. 
     In some examples, the radiating layer  20  may have therein a plurality of slits  21 , and the plurality of slits  21  may be arranged in a plurality of loops (or turns or rings or circles). Further, the slits  21  in each loop are uniformly spaced apart from each other, and a distance between any adjacent two of the plurality of loops is a constant. As such, a electromagnetic wave radiated by the antenna including slits  21  according to an embodiment of the present disclosure is distributed uniformly. It should be noted that, as shown in  FIG.  2   , in an embodiment of the present disclosure, the structure of the slot antenna is exemplified as a cylinder, and therefore, the slits  21  in each loop are arranged on a circle (or arranged to form a circle). If the slot antenna has a structure of a cube, the slits  21  in each loop may be arranged on a square (or arranged to form a square). Alternatively, as shown in  FIG.  2   , the radiating layer  20  may have a shape of a circle, and the slits  21  in each loop are arranged on a circle (or arranged to form a circle), while a profile of an edge of the radiating layer  20  may be a square. That is, a shape of the profile of the antenna including slits  21  may be different from a shape of a radiation area, i.e., may be different from a shape formed by the arrangement of the slits  21  in each loop in the radiation area. 
     It should be noted that, a shape of each slit  21  is not limited in an embodiment of the present disclosure, and includes, but is not limited to, a linear shape or the like. 
     In addition, the plurality loops of slits  21  are concentrically arranged, and a feeding point of the feeding element  50  corresponds to a center of the plurality loops of slits  21 . Such an arrangement can result in more uniform radiation of an electromagnetic wave. 
     In some examples, the radiating layer  20  have therein a plurality of slits  21 , and the plurality of slits  21  are arranged in a spiral shape (or arranged to from a spiral shape). Further, a distance between any adjacent two of the plurality of slits  21  is constant along an arrangement direction of the plurality of slits  21  (or along a direction in which the plurality of slits  21  are arranged). It should be noted that, in a case where the plurality of slits  21  are arranged in a spiral shape, the arrangement direction of the plurality of slits  21  refers to a direction of a curve formed by successively connecting centers of the plurality of slits  21  together. As such, an electromagnetic wave radiated from the antenna including slits  21  according to the present embodiment is distributed uniformly. 
     In some embodiments, the feeding point of the feeding element  50  is located at a center of the first shielding layer  30 , which facilitates uniform radiation of an electromagnetic wave. 
     In some examples, the thickness of the dielectric layer  10  ranges from about 100 μm to about 10 mm, and depends on the dielectric constant of the dielectric layer  10  and the operating frequency of the antenna. 
     In some examples, the feeding element  50  may be a probe. An opening is disposed in the first shielding layer  30 , and a half-hole (or semi-hole) is formed in the dielectric layer  10  at a position corresponding to the opening. The probe is fed into the half-hole of the dielectric layer  10  through the opening in the first shielding layer  30 , and the feeding element  50  is connected to the first shielding layer  30  by welding. 
     For the antenna shown in each of  FIGS.  1  to  7   , since the slits  21  of the antenna are arranged to form concentric circles or a spiral shape, and the feeding element  50  feeds power upwards from the first shielding layer  30 , the antenna is a two-dimensional scanning antenna.  FIG.  8    is a schematic diagram showing a simulation of one switch unit  60  in the antenna shown in each of  FIGS.  1  to  7   , and the result (which is optional) of the simulation is as follows. When the switch unit  60  is in a turn-on state, i.e., a certain gap exists between the first electrode and the second electrode  65 , the antenna can achieve a gain of −7.89 dB. When the switch unit  60  is in a turn-off state, i.e., the first electrode is in contact with the corresponding slit  21  in the radiating layer  20 , the antenna can achieve a gain of −15.88 dB. The result indicates that the radiation and shielding of a microwave can be achieved by controlling the state of the switch unit  60 . 
     In some examples,  FIG.  9    is a top view showing another antenna according to an embodiment of the present disclosure, and  FIG.  10    is a side view of the antenna shown in  FIG.  9   . As shown in  FIGS.  9  and  10   , the slits  21  of the antenna are arranged side by side on a straight line, and one switch unit  60  is arranged at a position corresponding to each of the slits  21 . The antenna is a one-dimensional scanning antenna, and a feeding element  50  of the antenna may be arranged at each of the left and right sides of the antenna. The arrows shown in  FIGS.  9  and  10    illustrate a configuration of feeding a microwave into the antenna from the left side. A turn-on state and a turn-off state of each switch unit  60  may be realized in the same manner as described above, thereby realizing the radiation and shielding of a microwave. 
     In some examples, each of the first shielding layer  30 , the second shielding layer  70 , the radiating layer  20 , the first electrode, the second electrode  65 , and the connecting portion  64  may be made of a material of metal, which in particular includes, but is not limited to, a low-resistance and low-loss metal such as copper, gold, silver, or the like, and may be manufactured by magnetron sputtering, thermal evaporation, electroplating, and/or the like. 
     In a second aspect, an embodiment of the present disclosure provides a communication apparatus, which includes the antenna according to any one of the foregoing embodiments. The communication apparatus can achieve the same advantages as those of the antenna, and detailed description thereof is omitted here. 
     It should be noted that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present disclosure, and the present disclosure is not limited thereto. It will be apparent to one of ordinary skill in the art that various modifications and improvements may be made therein without departing from the spirit and scope of the present disclosure, and such modifications and improvements are also considered to fall within the scope of the present disclosure.