Patent Publication Number: US-2023163473-A1

Title: Micro-wave transducer and manufacturing method thereof

Description:
TECHNICAL FIELD 
     The present invention belongs to the technical field of communication, and particularly relates to a micro-wave transducer and a manufacturing method thereof. 
     BACKGROUND 
     Compared with 4G (the 4th generation mobile communication technology), 5G (5th generation mobile communication technology) has the advantages of higher data rate, larger network capacity, lower time delay and the like. A 5G frequency plan includes two parts, namely, a low frequency band and a high frequency band, wherein the low frequency band (3-6 GHz) has good propagation characteristics and very abundant spectrum resources, so that development of a transducer unit and an array applied for the low frequency band communication gradually becomes a research and development hotspot at present. 
     SUMMARY 
     The present invention aims to solve at least one technical problem in the prior art and provides a micro-wave transducer and a manufacturing method thereof. 
     In a first aspect, an embodiment according to the present disclosure provides a micro-wave transducer, which includes: 
     a dielectric layer having a first surface and a second surface opposite to each other; 
     a first electrode layer on the first surface of the dielectric layer and with at least one first opening therein; 
     at least one transducer electrode on the second surface of the dielectric layer, wherein an orthographic projection of one of the at least one transducer electrode on the dielectric layer is within an orthographic projection of one of the at least one first opening on the dielectric layer; and 
     at least one first microstrip line on the second surface of the dielectric layer, wherein one of the at least one first microstrip line is electrically connected to one of the at least one transducer electrode; 
     wherein one of the at least one transducer electrode, an orthographic projection of which on the dielectric layer is within an orthographic projection of one of the at least one first opening, the first opening and one of the at least one first microstrip line electrically connected to the transducer electrode form one transducer unit; 
     in the transducer unit, an orthographic projection of a first side of the first opening on the dielectric layer and an orthographic projection of a second side of the first microstrip line on the dielectric layer intersect at a first intersection point; an orthographic projection of the transducer electrode on the dielectric layer and an orthographic projection of the first microstrip line on the dielectric layer intersect at a second intersection point; and a distance between the first intersection point and the second intersection point is a first distance; and 
     a maximum distance of the first opening along a normal direction through the first intersection point is a second distance, and the first distance is less than or equal to half of the second distance. 
     In the transducer unit, a ratio of an area of the orthographic projection of the transducer electrode on the dielectric layer to an area of the orthographic projection of the first opening on the dielectric layer is 0.017 to 0.67. 
     In the transducer unit, an orthographic projection of a center of the first opening on the dielectric layer, an orthographic projection of a center of the transducer electrode on the dielectric layer, and the first intersection point are on a same straight line. 
     The first opening includes a third side and a fourth side connected to the first side, and the transducer electrode includes a fifth side and a sixth side connected to the second side; 
     a distance between orthographic projections of the third side and the fifth side on the dielectric layer is a third distance, and a distance between orthographic projections of the fourth side and the sixth side on the dielectric layer is a fourth distance; and 
     the third distance is greater than or equal to the first distance, and the fourth distance is greater than or equal to the first distance. 
     The third distance is equal to the fourth distance. 
     The first opening has substantially a same shape as the transducer electrode. 
     The micro-wave transducer further includes a feeding unit electrically connected to the at least one first micro-strip line. 
     The at least one first opening includes 2 n  first openings, and at least two of the first openings have a same shape and a same size; 
     the feeding unit further includes n stages of second microstrip lines; and 
     one second microstrip line at a 1 st  stage is connected to two adjacent first microstrip lines, and the first microstrip lines connected to different second microstrip lines at the 1 st  stage are different; one second microstrip line at an m th  stage is connected to two adjacent second microstrip lines at an (m−1) th  stage, and the second microstrip lines at the (m−1) th  stage connected to different second microstrip lines at the m th  stage are different; wherein n is greater than or equal to 2, m is greater than or equal to 2 and less than or equal to n, and both m and n are integers. 
     The micro-wave transducer includes a transducing region and a feeding region; the at least one transducer electrode is in the transducing region, and the feeding unit is in the feeding region; the first electrode layer is in the transducing region and the feeding region; and 
     the first electrode layer includes a first sub-electrode in the transducing region and a second sub-electrode in the feeding region; and an orthographic projection of the second sub-electrode on the dielectric layer covers an orthographic projection of the feeding unit on the dielectric layer. 
     The first electrode layer has at least one second opening therein, the at least one second opening is in the feeding region; and 
     an orthographic projection of the at least one second opening on the dielectric layer is not overlapped with the orthographic projection of the feeding unit on the dielectric layer. 
     The orthographic projection of the second sub-electrode on the dielectric layer covers an orthographic projection of the n stages of second microstrip lines on the dielectric layer; and at a same position on the dielectric layer, a line width of the orthographic projection of one second microstrip of the n stages of second microstrip lines is less than or equal to 0.5 times a width of the orthographic projection of the second sub-electrode. 
     An orthographic projection of at least one stage of the n stages of second microstrip lines on the dielectric layer divides the orthographic projection of the second sub-electrode on the dielectric layer into two parts with different areas. 
     The first electrode layer is has at least one third opening therein; the at least one third opening is in the transducing region; and 
     a total area of the at least one second opening is greater than a total area of the at least one third opening. 
     The dielectric layer is a flexible material; and 
     the flexible material includes at least one of polyimide and polyethylene terephthalate. 
     The dielectric layer includes a first dielectric sub-layer, a first adhesive layer, a second dielectric sub-layer, a second adhesive layer and a third dielectric sub-layer, which are stacked; a surface of the first dielectric sub-layer away from the first adhesive layer serves as the first surface of the dielectric layer, and a surface of the third dielectric sub-layer away from the second adhesive layer serves as the second surface of the dielectric layer; and 
     a material of the first dielectric sub-layer and the third dielectric sub-layer includes polyimide, and a material of the second dielectric sub-layer includes polyethylene terephthalate. 
     The dielectric layer includes a first dielectric sub-layer, a first adhesive layer, a second dielectric sub-layer, a second adhesive layer and a third dielectric sub-layer, which are stacked, wherein a surface of the first dielectric sub-layer close to the first adhesive layer serves as the first surface of the dielectric layer, and a surface of the third dielectric sub-layer close to the second adhesive layer serves as the second surface of the dielectric layer; and 
     a material of the first dielectric sub-layer and the third dielectric sub-layer includes polyimide, and a material of the second dielectric sub-layer includes polyethylene terephthalate. 
     The dielectric layer includes a first dielectric sub-layer, a first adhesive layer and a second dielectric sub-layer, which are stacked, a surface of the first dielectric sub-layer away from the first adhesive layer serves as the first surface of the dielectric layer, and a surface of the second dielectric sub-layer away from the first adhesive layer serves as the second surface of the dielectric layer; and 
     a material of the first dielectric sub-layer includes polyimide, and a material of the second dielectric sub-layer includes polyethylene terephthalate, or, 
     a material of the first dielectric sub-layer includes polyethylene terephthalate, and a material of the second dielectric sub-layer includes polyimide. 
     A thickness of the second dielectric sub-layer is greater than a thickness of the first dielectric sub-layer or the third dielectric sub-layer; and thicknesses of the first dielectric sub-layer and the third dielectric sub-layer are equal to each other. 
     A ratio of a thickness of the dielectric layer to a thickness of the transducer electrode is 20 to 450. 
     The micro-wave transducer further includes a protective layer on a side of the transducer electrodes away from the dielectric layer; and 
     an orthographic projection of the protective layer on the dielectric layer covers an orthographic projection of the transducer electrodes on the dielectric layer. 
     In a second aspect, an embodiment of the present disclosure provided a manufacturing method of a micro-wave transducer, including: 
     providing a dielectric layer; 
     forming a first electrode layer on a first surface of the dielectric layer through a patterning process, such that at least one first opening is formed in the first electrode layer; and 
     forming a pattern including at least one transducer electrode and at least one first microstrip line on a second surface of the dielectric layer through a patterning process; wherein an orthographic projection of one of the at least one transducer electrode on the dielectric layer is within an orthographic projection of one of the at least one first opening on the dielectric layer. 
     The dielectric layer includes a first dielectric sub-layer, a first adhesive layer, a second dielectric sub-layer, a second adhesive layer and a third dielectric sub-layer, which are sequentially stacked; and the manufacturing method includes: providing the first dielectric sub-layer; 
     forming the first electrode layer on the first dielectric sub-layer through a patterning process; 
     coating the first adhesive layer on a side of the first dielectric sub-layer away from the first electrode layer, forming the second dielectric sub-layer on the first adhesive layer, then forming the second adhesive layer on a surface of the second dielectric sub-layer away from the first adhesive layer, and forming the third dielectric sub-layer on the second adhesive layer; and 
     forming the pattern including the at least one transducer electrode and the at least one first microstrip line on the third dielectric sub-layer through a patterning process. 
     The dielectric layer includes a first dielectric sub-layer, a first adhesive layer, a second dielectric sub-layer, a second adhesive layer and a third dielectric sub-layer, which are sequentially stacked; the manufacturing method includes: 
     providing the first dielectric sub-layer; 
     forming a first electrode layer on the first dielectric sub-layer through a patterning process; 
     providing the third dielectric sub-layer; 
     forming the pattern including the at least one transducer electrode and the at least one first microstrip line on the third dielectric sub-layer through a patterning process; and 
     providing the second dielectric sub-layer, and bonding a side of the first dielectric sub-layer, on which the first electrode layer is formed, with the second dielectric sub-layer through the first adhesive layer, and bonding a side of the second dielectric sub-layer, on which the at least one transducer electrode and the at least one first microstrip line are formed, with the second dielectric sub-layer. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a cross-sectional view of a micro-wave transducer in an embodiment according to the present disclosure. 
         FIG.  2    is a top view of a micro-wave transducer in an embodiment according to the present disclosure. 
         FIG.  3    is a schematic diagram of a transducer unit in an embodiment according to the present disclosure. 
         FIG.  4    is a cross-sectional view of another micro-wave transducer in an embodiment according to the present disclosure. 
         FIG.  5    is a cross-sectional view of another micro-wave transducer in an embodiment according to the present disclosure. 
         FIG.  6    is a cross-sectional view of another micro-wave transducer in an embodiment according to the present disclosure. 
         FIG.  7    is a top view of another micro-wave transducer in an embodiment according to the present disclosure. 
         FIG.  8    is a top view of another micro-wave transducer in an embodiment according to the present disclosure. 
         FIG.  9    is a top view of another micro-wave transducer in an embodiment according to the present disclosure. 
         FIG.  10    is a top view of another micro-wave transducer in an embodiment according to the present disclosure. 
         FIG.  11    is a top view of another micro-wave transducer in an embodiment according to the present disclosure. 
         FIG.  12    is a top view of another micro-wave transducer in an embodiment according to the present disclosure. 
         FIG.  13    is a schematic diagram of another transducer unit in an embodiment according to the present disclosure. 
     
    
    
     DETAIL DESCRIPTION OF EMBODIMENTS 
     In order to enable one of ordinary skill in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific 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 this disclosure belongs. The use of “first,” “second,” and the like in the present disclosure is not intended to indicate any order, quantity, or importance, but rather serves to distinguish one element from another. Also, the use of the terms “a,” “an,” or “the” and the like does not denote a limitation of quantity, but rather denotes the presence of at least one. The word “comprising” or “comprises”, and the like, means that the element or item preceding the word includes the element or item listed after the word and its equivalent, but does not exclude other elements or items. The terms “connected” or “coupled” and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Upper”, “lower”, “left”, “right”, and the like are used only to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly. 
     In a first aspect,  FIG.  1    is a cross-sectional view of a micro-wave transducer in an embodiment according to the present disclosure;  FIG.  2    is a top view of a micro-wave transducer in an embodiment according to the present disclosure;  FIG.  3    is a schematic diagram of a transducer unit in an embodiment according to the present disclosure; as shown in  FIGS.  1  to  3   , an embodiment according to the present disclosure provides a micro-wave transducer, which includes a dielectric layer  1 , a first electrode layer  2 , transducer electrodes  31  and a first microstrip line  32 . 
     The dielectric layer  1  includes a first surface and a second surface which are oppositely arranged. For example, as shown in  FIG.  1   , the first surface is a lower surface of the dielectric layer  1 , and the second surface is an upper surface of the dielectric layer  1 . 
     The first electrode layer  2  is arranged on the first surface of the dielectric layer  1 , and at least one first opening  21  is arranged in the first electrode layer  2 . A voltage written to the first electrode layer  2  is a reference voltage; the reference voltage includes, but is not limited to, a ground voltage. 
     Transducer electrodes  31  are arranged on the second surface of the dielectric layer  1 , and an orthographic projection of one transducer electrode  31  on the dielectric layer  1  is within an orthographic projection of one corresponding first opening  21  on the dielectric layer  1 . For example, the transducer electrodes  31  and the first openings  21  are arranged in a one-to-one correspondence. 
     The first microstrip lines  32  are arranged on the second surface of the dielectric layer  1 , and configured to feed the transducer electrodes  31 . The first microstrip lines  32  may be directly electrically connected to the transducer electrodes  31 . For example, the first microstrip lines  32  are connected to the transducer electrodes  31  in a one-to-one correspondence. Alternatively, the first microstrip line  32  may also feed the transducer electrode  31  by way of coupling. For example, orthographic projections of the first microstrip line  32  and the transducer electrode  31  on the dielectric layer  1  at least partially overlap with each other. In an embodiment according to the present disclosure, as an example, the first microstrip line  32  and the transducer element  31  are directly connected to each other. 
     In an embodiment according to the present disclosure, a first opening  21  in the first electrode layer  2 , a transducer electrode  31  in the first opening  21 , and a first microstrip line  32  connected to the transducer electrode form a transducer unit. For the transducer unit, orthographic projections of the first microstrip line  32  and the first opening  21  on the dielectric layer  1  intersect with each other at a first intersection point P 1 , and orthographic projections of the first microstrip line  32  and the transducer electrode  31  on the dielectric layer intersect with each other at a second intersection point P 2 . The first intersection point P 1  and the second intersection point P 2  are separated by a first distance d 1 . A maximum distance of the first opening along the normal direction through the first intersection point P 1  is a second distance d 2 , the first distance d 1  is less than or equal to half of the second distance d 2 , i.e., the distance between the first intersection point P 1  and the second intersection point P 2  is small, that is, the distance between the first opening  21  and the transducer electrode  31  at a feeding end of the first microstrip line  32  is small, which helps to expand the bandwidth of the transducer unit, thereby realizing a high-bandwidth micro-wave transducer. In addition, for the first opening  21  in the first electrode layer  2 , at a high frequency band of the ultra wide band, the transducer electrode  31  serves as the main radiation source, and has a structural prototype equivalent to a monopole micro-wave transducer. At a low frequency band, the transducer electrode  31  and the first opening  21  increase the capacitive characteristic of the micro-wave transducer. Experiments prove that the micro-wave transducer provided in an embodiment according to the present disclosure operates in a 5G Sub-6 GHz frequency band (a frequency band of less than 6 GHz in 5G), may be attached to a window, and is connected with an indoor CPE (Customer Premise Equipment) through a low-loss cable, so that the space loss is reduced, and the internet experience of a user is improved to a certain extent. 
     In some examples, a ratio of an area of an orthographic projection of the first opening  21  on the dielectric layer to an area of an orthographic projection of the transducer electrode  31  in one transducer unit on the dielectric layer is 0.017 to 0.67. In an embodiment according to the present disclosure, the areas of the first opening  21  and the transducer electrode  31  are reasonably set, thereby ensuring a width of a slit between the first opening  21  and the transducer electrode  31 , and further expanding the operating bandwidth of the micro-wave transducer. 
     In some examples, in each of at least some of the transducer units, a center of the orthographic projection of the transducer electrode  31  on the dielectric layer  1 , a center of the orthographic projection of the first opening  21  on the dielectric layer  1 , and the first intersection point P 1  are on a same straight line. That is, for one transducer unit, the first opening  21  and the transducer element  31  have the same symmetry axis, so that impedance matching may be performed well and radiation efficiency of micro-wave signals may be improved. In an embodiment according to the present disclosure, as an example, in each transducer unit, the center of the orthographic projection of the transducer electrode  31  on the dielectric layer  1 , the center of the orthographic projection of the first opening  21  on the dielectric layer  1 , and the first intersection point P 1  are on a same straight line. 
     In some examples, the first opening  21  in the first electrode layer  2  includes a first side  101 , and a third side  103  and a fourth side  104  connected to the first side  101 . For example, a shape of the first opening  21  is triangular. Meanwhile, the transducer element  31  includes a second side  102 , and a fifth side  105  and a sixth side  106  connected to the second side  102 . For example, a shape of the transducer element  31  is triangular. In each of at least some of the transducer units, a distance between orthographic projections of the third side  103  and the fifth side  105  on the dielectric layer is a third distance d 3 , and a distance between orthographic projections of the fourth side  104  and the sixth side  106  on the dielectric layer is a fourth distance d 4 . At least one of the third distance d 3  and the fourth distance d 4  is greater than or equal to the first distance d 1 . For example, the third distance d 3  and the fourth distance d 4  are both greater than or equal to the first distance d 1 , i.e., the distance between the first opening  21  and the transducer electrode  31  at the feeding end of the first microstrip line is small, which helps to expand the bandwidth of the transducer unit, thereby realizing a high-bandwidth micro-wave transducer. In some examples, a ratio of a thickness of the dielectric layer  1  to a thickness of the transducer electrode  31  is 20 to 450. By selecting the appropriate thickness ratio of the dielectric layer  1  to the transducer electrode  31 , the radiation performance of the micro-wave transducer may be improved. 
     In some examples, as shown in  FIG.  1   , the dielectric layer  1  in the micro-wave transducer includes, but is not limited to, flexible materials. For example, the dielectric layer  1  is made of Polyimide (PI). Alternatively, the dielectric layer  1  may also be made of glass-based materials. In some examples, when the dielectric layer  1  is made of PI materials, its thickness is about 0.2 mm, and its Dk/Df is about 3.2/0.004. When the dielectric layer  1  is a PI substrate, the transducer electrode  31  is arranged on the upper surface of the PI substrate, and meanwhile, a protective layer  4 , such as a self-repairing transparent waterproof coating, is further formed on a side of the transducer electrodes  31  away from the PI substrate, to protect the transducer electrodes  31 . 
     In some examples,  FIG.  4    is a cross-sectional view of another micro-wave transducer in an embodiment according to the present disclosure; as shown in  FIG.  4   , the dielectric layer  1  in the micro-wave transducer is a composite film layer, and includes a first dielectric sub-layer  11 , a first adhesive layer  12 , a second dielectric sub-layer  13 , a second adhesive layer  14 , and a third dielectric sub-layer  15 , which are sequentially stacked. The first electrode layer  2  is arranged on a side of the first dielectric sub-layer  11  away from the first adhesive layer  12 , i.e., the side of the first dielectric sub-layer  11  away from the first adhesive layer  12  serves as the first surface of the dielectric layer  1 . The transducer electrodes  31  are arranged on a side of the third dielectric sub-layer  15  away from the second adhesive layer  14 , i.e., the side of the second dielectric sub-layer  13  away from the second adhesive layer  14  serves as the second surface of the dielectric layer  1 . In this case, the transducer elements  31  and the first microstrip lines  32  are arranged on the upper surface of the third dielectric sub-layer  15 , and then a connector may be soldered directly on the third dielectric sub-layer  15  to provide the micro-wave signals for the first microstrip lines  32 . The first electrode layer  2  is arranged on the lower surface of the first dielectric sub-layer  11 , which facilitates to provide a ground voltage to the first electrode layer  2 . In some examples, the first dielectric sub-layer  11  and the third dielectric sub-layer  15  include, but are not limited to, PI materials; the second dielectric sub-layer  13  includes, but is not limited to, polyethylene terephthalate (PET). The materials of the first adhesive layer  12  and the second adhesive layer  14  may be transparent optically clear adhesive (OCA). When the transducer electrodes  31  are arranged on the side of the third dielectric sub-layer  15  away from the second adhesive layer  14 , the protective layer  4 , such as the self-repairing transparent waterproof coating, is further formed on the side of the transducer electrodes  31  away from the third dielectric sub-layer  15 , to protect the transducer electrodes  31 . 
     In some examples,  FIG.  5    is a cross-sectional view of another micro-wave transducer in an embodiment according to the present disclosure; as shown in  FIG.  5   , the dielectric layer  1  in the micro-wave transducer has the same structure as the dielectric layer  1  in the micro-wave transducer shown in  FIG.  3   , and includes the first dielectric sub-layer  11 , the first adhesive layer  12 , the second dielectric sub-layer  13 , the second adhesive layer  14 , and the third dielectric sub-layer  15 , which are sequentially stacked. The first electrode layer  2  is arranged on a side of the first dielectric sub-layer  11  close to the first adhesive layer  12 , i.e., the side of the first dielectric sub-layer  11  close to the first adhesive layer  12  serves as the first surface of the dielectric layer  1 . The transducer electrodes  31  are arranged on a side of the second dielectric sub-layer  13  close to the second adhesive layer  14 , i.e., the side of the second dielectric sub-layer  13  close to the second adhesive layer  14  serves as the second surface of the dielectric layer  1 . In this case, the first microstrip lines, the transducer elements and the first electrode layer are not exposed to the outside, so that water and oxygen corrosion may be effectively prevented. In some examples, the first dielectric sub-layer  11  and the third dielectric sub-layer  15  include, but are not limited to, PI materials; the second dielectric sub-layer  13  includes, but is not limited to, polyethylene terephthalate (PET). The materials of the first adhesive layer  12  and the second adhesive layer  14  may be transparent optically clear adhesive (OCA). When the transducer electrodes  31  are arranged between the third dielectric sub-layer  15  and the second adhesive layer  14 , the protective layer  4 , such as the self-repairing transparent waterproof coating, is further formed on the upper surface of the third dielectric sub-layer  15 , to protect the third dielectric sub-layer  15 . 
     As shown in  FIGS.  4  and  5   , when the dielectric layer  1  includes the first dielectric sub-layer  11 , the first adhesive layer  12 , the second dielectric sub-layer  13 , the second adhesive layer  14 , and the third dielectric sub-layer  15 , which are sequentially stacked. The first dielectric sub-layer  11  and the third dielectric sub-layer  15  may be made of the same material, and thicknesses of the first dielectric sub-layer  11  and the third dielectric sub-layer  15  are the same or substantially the same. The second dielectric sub-layer  13  is different from the first dielectric sub-layer  11  (or the third dielectric sub-layer  15 ) in material and thickness, and a thickness of the second dielectric sub-layer  13  is greater than that of the first dielectric sub-layer  11 . The thickness of the first dielectric sub-layer  11  (or the third dielectric sub-layer  15 ) is about 10 μm to 80 μm, and the thickness of the second dielectric sub-layer  13  is about 0.2 mm to 0.7 mm. 
     In some examples,  FIG.  6    is a cross-sectional view of another micro-wave transducer in an embodiment according to the present disclosure; as shown in  FIG.  5   , the dielectric layer  1  in the micro-wave transducer includes the first dielectric sub-layer  11 , the first adhesive layer  12 , and the second dielectric sub-layer  13 , which are stacked. A surface of the first dielectric sub-layer  11  away from the first adhesive layer  12  serves as the first surface of the dielectric layer  1 , i.e., the first electrode layer  2  is arranged on a side of the first dielectric sub-layer away from the first adhesive layer  12 . The surface of the second dielectric sub-layer  13  away from the first adhesive layer  12  serves as the second surface of the dielectric layer  1 , i.e., the transducer electrodes are arranged on the side of the second dielectric sub-layer  13  away from the first adhesive layer  12 . The material of the first dielectric sub-layer  11  includes polyimide, and the material of the second dielectric sub-layer  13  includes polyethylene terephthalate; alternatively, the material of the first dielectric sub-layer  11  includes polyethylene terephthalate, and the material of the second dielectric sub-layer  13  includes polyimide. 
     In some examples, the micro-wave transducer includes not only the above-described dielectric layer  1 , the first electrode layer  2 , the transducer electrodes  31  and the first microstrip lines  32 , but also the feeding unit  5 . The feeding unit  5  may be arranged on the second surface of the dielectric layer  1 ; and an orthographic projection of the feeding unit  5  on the dielectric layer  1  at least partially overlap with an orthographic projection of the first microstrip lines  32  on the dielectric layer  1 ; and the feeding unit  5  is configured to feed the first microstrip lines  32 . 
     In some examples, when the number of the first openings  21  is 2 n , and shapes and sizes of at least two first openings are the same, the feeding unit  5  may include n stages of second microstrip lines  51 . One of the second microstrip lines  51  at the 1st stage is connected to two adjacent first microstrip lines  32 , and the first microstrip lines  32  connected to different second microstrip lines  51  at the 1st stage are different. One of the second microstrip lines  51  at the m th  stage is connected to two adjacent second microstrip lines  51  at the (m−1) th  stage, and the second microstrip lines  51  at the (m−1) th  stage connected to different second microstrip lines  51  at the m th  stage are different, wherein n is greater than or equal to 2, m is greater than or equal to 2 and less than or equal to n, and both m and n are integers. 
     It should be noted that, in the embodiment according to the present disclosure, as an example, the first microstrip line  32  is directly connected to the second microstrip line  51  of the feeding unit  5 . In this case, the first microstrip line  32  and the second microstrip line  51  may be arranged in the same layer and be made of the same material. Meanwhile, the transducer electrodes  31  may also be directly connected to the first microstrip lines  32 , so that the transducer electrodes  31 , the first microstrip lines  32 , and the second microstrip lines  51  may be arranged in the same layer and be made of the same material, i.e., they may be formed in a same patterning process, thereby reducing the process cost and improving the production efficiency. Alternatively, in the embodiment according to the present disclosure, the first microstrip lines  32  and the feeding unit  5  are arranged in different layers, as long as orthographic projections of the first microstrip line  32  and the second microstrip line  51  at the 1st stage on the dielectric layer  1  overlap with each other. For example, when the dielectric layer  1  includes the first dielectric sub-layer  11 , the first adhesive layer  12 , the second dielectric sub-layer  13 , the second adhesive layer  14 , and the third dielectric sub-layer  15 , which are sequentially stacked, the first microstrip lines  32  are arranged on a side of the second dielectric sub-layer  13  away from the first dielectric sub-layer  11 , the second microstrip lines  51  are arranged on a side of the second dielectric sub-layer  13  close to the first dielectric sub-layer  11 , and orthographic projections of the first microstrip line  32  and the corresponding second microstrip line  51  on the first dielectric sub-layer  11  are overlapped. At this time, the second microstrip line  51  of the feeding unit  5  may feed the first microstrip line  32  by way of coupling. 
     In some examples, the first opening  21  in the first electrode layer  2  includes, but is not limited to, an arc shape or a triangular shape. Alternatively, the first opening  21  in the first electrode layer  2  may also be circular, rectangular, etc. Accordingly, the shape of the transducer electrode  31  may be adapted to the shape of the first opening  21 , i.e., the shape of the transducer electrode  31  is the same as the shape of the first opening  21 . Alternatively, the shape of the transducer electrode  31  may be different from the shape of the first opening  21 , for example, the transducer electrode  31  has a triangular shape and the first opening  21  has a rectangular shape. It should be noted that the shapes of the first opening  21  and the transducer electrode  31  are not limited in the embodiment according to the present disclosure as long as the orthographic projection of the transducer electrode  31  on the dielectric layer  1  is within the orthographic projection of the first opening  21  on the dielectric layer  1 . 
     The structure of the first opening  21  in the first electrode layer  2  and the transducer electrode  31  in the embodiment according to the present disclosure is explained below with reference to specific examples. 
     In one example, as shown in  FIG.  7   , the first openings  21  in the first electrode layer  2  are an arc-shaped first opening  21  and are on one side of the first electrode layer  2  in the length direction, and the transducer electrodes  31  adopt a circular transducer electrode  31 . In  FIG.  2   , as an example, the number of the first openings  21  in the first electrode layer  2  is 8, and the transducer electrodes  31  are arranged in one-to-one correspondence with the first openings  21 . In this case, one transducer electrode  31  is connected to one first microstrip line  32 , i.e., there are  8  first microstrip lines  32 . The feeding unit  5  includes  3  stages of second microstrip lines  51 , wherein each of the second microstrip lines  51  at the 1st stage is connected to two adjacent first microstrip lines  32 , and the first transmission lines connected to different second microstrip lines  51  at the 1st stage are different. For example, from top to bottom, the 1st second microstrip line  51  at the 1st stage is connected to the first microstrip lines  32  to which the 1st and 2nd transducer electrodes  31  are connected; the 2nd second microstrip line  51  is connected to the first microstrip lines  32  to which the 3rd and the 4th transducer electrodes  31  are connected; the 3rd second microstrip line  51  is connected to the first microstrip lines  32  to which the 5th and the 6th transducer electrodes  31  are connected; the 4th second microstrip line  51  is connected to the first microstrip lines  32  to which the 7th and the 8th transducer electrodes  31  are connected. Each of the second microstrip lines  51  at the 2nd stage is connected to two adjacent second microstrip lines  51  at the 1st stage, and the second microstrip lines  51  at the 1st stage connected to different second microstrip lines  51  at the 2nd stage are different. For example, from top to bottom, the 1st second microstrip line  51  at the 2nd stage is connected to the 1st and 2nd second microstrip lines  51  at the 1st stage; the 2nd second microstrip line  51  of the 2nd stage is connected to the 3rd and 4th second microstrip lines  51  at the 1st stage. The second microstrip line  51  at the 3rd stage is connected to the two second microstrip lines  51  at the 2nd stage. Alternatively, the feeding unit  5  includes not only the second microstrip lines  51  but also the transformer  6 , and the transformer  6  is connected to the second microstrip line  51  at nth stage. 
     Here, it should be noted that, in the above description, the first openings  21  are provided only on one side of the first electrode layer  2  in the length direction as an example. In an actual product, the first openings  21  may be provided on both sides of the first electrode layer  2  in the length direction. For example, the two sides of the first electrode layer  2  in the length direction are provided with  8  first openings  21 , respectively; and the transducer electrode  31  is arranged at a position corresponding to each first opening  21 , and at this time, the first electrode layer  2  is mirror-symmetrical with respect to a perpendicular bisector of a wide side thereof. In this case, the feeding units  5  for the transducer electrodes  31  on both sides of the first electrode layer  2  in the length direction are the same, and two second microstrip lines  51  at the nth stage may be connected to one three-port transformer  6  to implement the feeding function. 
     With continued reference to  FIG.  7   , the first electrode layer  2  includes not only the first openings  21  but also auxiliary third openings  22  each of which is between the any two first openings  21  adjacently arranged. The third opening  22  includes, but is not limited to, a rectangular opening. In the embodiment according to the present disclosure, a radiation direction of the micro-wave signal may be adjusted through the third openings, and meanwhile, the optical transmittance of the micro-wave transducer is increased, and the visual effect is improved. 
     With continued reference to  FIG.  7   , a distance exists between orthographic projections of a center of any first opening  21  in the first electrode layer  2  and a center of the corresponding transducer electrode  31  on the dielectric layer  1 , i.e., the centers of the first opening  21  and the corresponding transducer electrode  31  are offset from each other, which facilitate to realize optimal impedance matching. 
     With continued reference to  FIG.  7   , the first microstrip line  32  may adopt an L-shaped structure, which includes a first portion and a second portion electrically connected to each other; and the first portion is connected to the transducer electrode  31 ; 
     the second portion is connected to the feeding unit  5  (for example, connected to the second microstrip line  51  at 1st stage); and an extending direction of the first portion is perpendicular to an extending direction of the second portion. A corner, where the first and second portions are connected to each other, may be rounded or flat chamfers. The corner, where the first and second portions are connected to each other, is preferably a non-right angle, so that the micro-wave signal is prevented from being reflected at the position, and the transmission loss of the micro-wave signal is prevented from being increased. 
     In some examples, the first microstrip line  32  is a 50Ω microstrip line, i.e., an impedance of the first microstrip line  32  is around 50Ω. Alternatively, a microstrip line with corresponding impedance may also be selected as the first microstrip line  32 , according to the parameter requirement on the gain of the micro-wave transducer. 
     In some examples, an arc of the first opening  21  is around 200° to 300°, and may be 250°, for example. The first opening  21  has a chord length of about 20 mm to 25 mm, for example, 22.7 mm. In an embodiment according to the present disclosure, an extending direction of the chord of the first opening  21  is parallel to the length direction of the first electrode layer  2 . In this case, if the third openings  22  are provided between the adjacent first openings  21 , a depth and a width of the third opening  22  are both about 20 mm to 30 mm. For example, the depth and width of the third opening  22  are both 25 mm. By reasonably setting the depth and width of the third opening, the optical transmittance of the micro-wave transducer may be effectively improved. 
     In another example,  FIG.  8    is a top view of another micro-wave transducer in an embodiment according to the present disclosure; as shown in  FIG.  8   , the first openings  21  of the micro-wave transducer are formed in the first electrode layer  2 , and the first openings  21  and the transducer electrodes  31  both adopt a triangle shape, i.e., the transducer electrode  31  is a triangle-shaped sheet structure, each transducer electrode  31  is connected to a first microstrip line  32 . The feeding unit  5  is the same as the feeding unit  5  shown in  FIG.  2   , and therefore, the details are not repeated here. The first electrode layer  2  in the embodiment according to the present disclosure is further provided with third openings  22 , each of which may be between the two first openings  21 . In the embodiment according to the present disclosure, the radiation direction of the micro-wave signal may be adjusted through the third openings, and meanwhile, the optical transmittance of the micro-wave transducer is increased, and the visual effect is improved. In an embodiment according to the present disclosure, when the first opening  21  is triangular, the third opening  22  may also be triangular, and the third opening  22  is equivalent to the first opening  21  rotated by 180°. 
     In another example,  FIG.  9    is a top view of another micro-wave transducer in an embodiment according to the present disclosure; as shown in  FIG.  9   , the micro-wave transducer includes a transducing region Q 1  and a feeding region Q 2 ; wherein the transducer electrodes  31  and the first openings  21  in the first electrode layer  2  are both arranged in the transducing region Q 1 , and the feeding unit  5  is arranged in the feeding region Q 2 . The structure of the micro-wave transducer is substantially similar to that of the micro-wave transducer shown in  FIG.  8   , the transducer electrode  31  and the first opening  21  in the first electrode layer  2  both have a triangular shape, i.e., the transducer electrode  31  has a triangle-shaped sheet structure. The difference between the micro-wave transducers shown in  FIGS.  8  and  9    lies in the first electrode layer  2 , specifically, the first electrode layer  2  of the micro-wave transducer shown in  FIG.  9    includes a first sub-electrode  23  in the transducing region Q 1  and a second sub-electrode  24  in the feeding region Q 2 ; an orthographic projection of the second sub-electrode  24  on the dielectric layer  1  covers an orthographic projection of the feeding unit  5  on the dielectric layer  1 . For example, an outline of the second sub-electrode  24  is the same as an outline of the feeding unit  5 . It should be understood that, even so, the orthographic projection of the first electrode layer  2  on the dielectric layer  1  covers the orthographic projection of the feeding unit  5  on the dielectric layer  1 . 
     With continued reference to  FIG.  9   , in some examples, the first electrode layer includes not only the first openings  21  in the transducing region, but also a second opening  25  in the feeding region Q 2 , and an orthographic projection of the second opening  25  on the dielectric layer  1  does not overlap with the orthographic projection of the feeding unit  5  on the dielectric layer  1 . The second opening  25  is provided, which not only improves the optical transmittance of the micro-wave transducer, but also changes the radiation direction of the micro-wave signal. 
     For example, when the number of the first openings  21  of the first electrode layer  2  is 2 n , the feeding unit  5  includes n stages of second microstrip lines  51 , at this time, the second opening  25  is arranged on a side of at least some of the second microstrip lines  51  close to the transducing region Q 1 . For example, in  FIG.  7   , the second opening  25  is provided on the left of the second microstrip line  51  at the 1st stage. 
     Further,  FIG.  10    is a top view of another micro-wave transducer in an embodiment according to the present disclosure; as shown in  FIG.  10   , the first sub-electrode  23  in the embodiment according to the present disclosure is further provided with third openings  22 , each of which may be between the two first openings  21 . In the embodiment according to the present disclosure, the radiation direction of the micro-wave signal may be adjusted through the third openings, and meanwhile, the optical transmittance of the micro-wave transducer is increased, and the visual effect is improved. In an embodiment according to the present disclosure, when the first opening  21  is triangular, the third opening  22  may also be triangular, and the third opening  22  is equivalent to the first opening  21  rotated by 180°. 
     In another example,  FIG.  11    is a top view of another micro-wave transducer in an embodiment according to the present disclosure; as shown in  FIG.  11   , the structure of the micro-wave transducer is substantially the same as that of the micro-wave transducer shown in  FIG.  7   , except for the first electrode layer  2 . Specifically, the second sub-electrode  24  in the first electrode layer  2  has the same pattern as the feeding unit  5 . For example, the feeding unit  5  includes second microstrip lines  51 , at this time, the pattern of the second sub-electrode  24  corresponds to the second microstrip line  51 , i.e., except for the pattern of the second sub-electrode  24  in the first electrode layer  2  at the position corresponding to the feeding unit  5 , the pattern at the remaining positions are hollowed out, that is, the second openings  25  are provided at positions of the second sub-electrode except for the position corresponding to the feeding unit  5 =. The other structures of the micro-wave transducer are the same as those of the micro-wave transducer shown in  FIG.  8   , and therefore, the details are not repeated here. 
       FIG.  12    is a top view of another micro-wave transducer in an embodiment according to the present disclosure; as shown in  FIG.  12   , the first sub-electrode  23  in the embodiment according to the present disclosure is further provided with third openings  22 , each of which may be between the two first openings  21 . In the embodiment according to the present disclosure, the radiation direction of the micro-wave signal may be adjusted through the third opening, and meanwhile, the optical transmittance of the micro-wave transducer is increased, and the visual effect is improved. In an embodiment according to the present disclosure, when the first opening  21  is triangular, the third opening  22  may also be triangular, and the third opening  22  is equivalent to the first opening  21  rotated by 180°. 
     In some examples, the total area of the third openings  22  in the first sub-electrode  23  is less than the total area of the second openings  25  in the second sub-electrode  24 . In an embodiment according to the present disclosure, through the cooperation of the second opening  25  and the third opening  25 , the radiation direction is adjusted, and further, the optical transmittance of the micro-wave transducer may be increased, and the visual effect may be improved. 
     In some examples, with continued reference to  FIGS.  11  and  12   , an orthographic projection of the second sub-electrode  24  on the dielectric layer  1  covers an orthographic projection of the second microstrip line  51  on the dielectric layer  1 ; and at the same position of the dielectric layer  1 , a line width of the orthographic projection of the second microstrip line  51  is less than or equal to 0.5 times a width of the orthographic projection of the second sub-electrode  24 . Therefore, the second microstrip line  51  may be fully covered by the second sub-electrode  24 , so as to reduce the loss caused by the outward radiation of the micro-wave signal. 
     In some examples, an orthographic projection of the the second microstrip line  51  at at least one stage on the dielectric layer  1  divides the orthographic projection of the second sub-electrode  24  on the dielectric layer  1  into two parts with unequal areas. That is, areas of orthographic projections of the second sub-electrode  24  on the dielectric layer  1 , on the left and right sides of the second microstrip line  51  are different. 
     It should be noted that, in the above description, as an example, the first opening  21  and the transducer element  31  have the same shape, but actually, shapes of the first opening  21  and the transducer element  31  may also be different, such as the transducer unit shown in  FIG.  13   . In this case, the first opening  21  may be an opening formed by splicing and combining a semicircular opening and a rectangular opening. In some examples, the materials of the first electrode layer  2 , the first microstrip line  32 , the second microstrip line  51 , and the transducer electrode  31  described above all include, but are not limited to, aluminum or copper. 
     Through experimental verification, factors influencing the performance of the micro-wave transducer mainly include the material and the dielectric constant/loss tangent (Dk/Df) of the dielectric layer  1 , the materials and the thicknesses of the first electrode layer  2  and the transducer electrode  31 , and the like, and are described below with reference to specific examples, wherein a center frequency of the micro-wave transducer is 3.75 GHz. 
     In a first example, a cross-sectional view of the micro-wave transducer is shown in  FIG.  5   , a top view of the micro-wave transducer is shown in  FIG.  8   . The dielectric layer  1  of the micro-wave transducer includes the first dielectric sub-layer  11 , the first adhesive layer  12 , the second dielectric sub-layer  13 , the second adhesive layer  14 , and the third dielectric sub-layer  15 , which are sequentially stacked; transducer electrodes  31 , first microstrip lines  32 , and the feeding unit  5  are arranged between the third dielectric sub-layer  15  and the second adhesive layer  14 ; and the first electrode layer  2  is arranged between the first dielectric sub-layer  11  and the first adhesive layer  12 . The first dielectric sub-layer  11  and the third dielectric sub-layer  15  adopt PI substrates with a thickness of 34 um, and Dk/Df is 3.46/0.0015. The second dielectric sub-layer  13  adopts a PET substrate with a thickness of 0.5 mm, and Dk/Df is 3.9/0.003. The first electrode layer  2  adopts aluminum material with a thickness of 0.6 um, and an arc-shaped groove is formed in the first electrode layer  2 . The transducer electrode  31  adopts aluminum material with a thickness of 1.2 um, and the transducer electrode  31  adopts a circular radiation patch. The first adhesive layer  12  and the second adhesive layer  14  adopt the OCA with a thickness of 5 um. The overall size of the micro-wave transducer is 62.4 mm*375 mm. It is realized through a simulation for the above structure that the −6 dB impedance bandwidth of the micro-wave transducer is 0.61 GHz and 0.65 GHz (3.20 GHz to 3.81 GHz, 3.85 GHz to 4.5 GHz); the gain of the micro-wave transducer is 7.45 dBi; the half-power beam width is 10°/203°; and the radiation efficiency of the micro-wave transducer is 64.3%. 
     In a second example, a cross-sectional view of the micro-wave transducer is shown in  FIG.  4   , a top view of the micro-wave transducer is shown in  FIG.  8   . The dielectric layer  1  of the micro-wave transducer includes the first dielectric sub-layer  11 , the first adhesive layer  12 , the second dielectric sub-layer  13 , the second adhesive layer  14  and the third dielectric sub-layer  15 , which are sequentially stacked; transducer electrodes  31 , first microstrip lines  32  and the feeding unit  5  are arranged between the third dielectric sub-layer  15  and the second adhesive layer  14 ; and the first electrode layer  2  is arranged between the first dielectric sub-layer  11  and the first adhesive layer  12 . The first dielectric sub-layer  11  and the third dielectric sub-layer  15  adopt PI substrates with a thickness of 60 um, and Dk/Df is 4.72/0.0047. The second dielectric sub-layer  13  adopts a PET substrate with a thickness of 0.5 mm, and Dk/Df is 2.77/0.0059. The first electrode layer  2  adopts aluminum material with a thickness of 1.2 um, and a triangular groove is formed in the first electrode layer  2 . The transducer electrode  31  adopts aluminum material with a thickness of 1.2 um, and the transducer electrode  31  adopts a triangular sheet structure. Both the first adhesive layer  12  and the second adhesive layer  14  adopt the OCA with a thickness of 5 um. The overall size of the micro-wave transducer is 100.98 mm*320 mm. It is realized through a simulation for the above structure that the −6 dB impedance bandwidth of the micro-wave transducer is 1.37 GHz (3.13 GHz to 4.5 GHz); the gain of the micro-wave transducer is 7.59 dBi; the half-power beam width is 12°/47°; and the radiation efficiency of the micro-wave transducer is 73.4%. 
     In a third example, a cross-sectional view of the micro-wave transducer is shown in  FIG.  4   , a top view of the micro-wave transducer is shown in  FIG.  9   . The dielectric layer  1  of the micro-wave transducer includes the first dielectric sub-layer  11 , the first adhesive layer  12 , the second dielectric sub-layer  13 , the second adhesive layer  14 , and the third dielectric sub-layer  15 , which are sequentially stacked; transducer electrodes  31 , first microstrip lines  32 , and the feeding unit  5  are arranged between the third dielectric sub-layer  15  and the second adhesive layer  14 ; and the first electrode layer  2  is arranged between the first dielectric sub-layer  11  and the first adhesive layer  12 . Portions of the micro-wave transducer which are same as those of the second example are not described again. The difference between them lies in that the micro-wave transducer includes the first sub-electrode  23  in the transducing region Q 1  and the second sub-electrode  24  in the feeding region Q 2  in the first electrode layer  2 ; triangular first openings  21  are formed in the first sub-electrode  23 ; the profile of the second sub-electrode  24  on a side away from the first sub-electrode  23  is matched with the profile of the feeding unit  5 , and a hollow pattern is arranged on a side of at least some of the second microstrip lines  51  close to the transducing region Q 1 . For example, in  FIG.  6   , a hollow opening pattern is arranged on the left side of the second microstrip line  51  at the 1st stage. This design of the first opening  21  may further improve the gain of the micro-wave transducer array. The overall size of the micro-wave transducer is still 100.98 mm*320 mm. It is realized through a simulation for the above structure that the −6 dB impedance bandwidth of the micro-wave transducer is 1.37 GHz (3.13 GHz to 4.5 GHz); the gain of the micro-wave transducer is 10.74 dBi; the half-power beam width is 12°/61°; and the radiation efficiency of the micro-wave transducer is 73.2%. 
     In a fourth example, a cross-sectional view of the micro-wave transducer is shown in  FIG.  3   , a top view of the micro-wave transducer is shown in  FIG.  9   . The dielectric layer  1  of the micro-wave transducer includes the first dielectric sub-layer  11 , the first adhesive layer  12 , the second dielectric sub-layer  13 , the second adhesive layer  14 , and the third dielectric sub-layer  15 , which are sequentially stacked; transducer electrodes  31 , first microstrip lines  32 , and the feeding unit  5  are arranged on a side of the third dielectric sub-layer  15  away from the second adhesive layer  14 ; and the first electrode layer  2  is arranged on a side of the first dielectric sub-layer  11  away from the first adhesive layer  12 . Compared with the third example, in the micro-wave transducer, only the positions of the transducer electrodes  31  and the first electrode layers  2  are changed, and the remaining film layers remain unchanged, and therefore, the details are not repeated here. The overall size of the micro-wave transducer is 98.93 mm*320 mm. It is realized through a simulation for the above structure that the −6 dB impedance bandwidth of the micro-wave transducer is 1.33 GHz (3.17 GHz to 4.5 GHz); the gain of the micro-wave transducer is 10.40 dBi; the half-power beam width is 12°/59°; and the radiation efficiency of the micro-wave transducer is 75.7%. 
     In a fifth example, a cross-sectional view of the micro-wave transducer is shown in  FIG.  3   , a top view of the micro-wave transducer is shown in  FIG.  9   . Compared with the fourth example, in the micro-wave transducer, only the array size is changed, and other film layers remain unchanged, and therefore, the details are not repeated here. The overall size of the micro-wave transducer is 97.43 mm*280 mm. It is realized through a simulation for the above structure that the −6 dB impedance bandwidth of the micro-wave transducer is 1.24 GHz (3.26 GHz to 4.5 GHz); the gain of the micro-wave transducer is 9.55 dBi; the half-power beam width is 14°/61°; and the radiation efficiency of the micro-wave transducer is 77.1%. 
     In a sixth example, a cross-sectional view of the micro-wave transducer is shown in  FIG.  3   , a top view of the micro-wave transducer is shown in  FIG.  11   . Compared with the fifth example, in the micro-wave transducer, the thickness and Dk/Df of each of the first dielectric sub-layer  11 , the second dielectric sub-layer  13 , the third dielectric sub-layer  15 , the first adhesive layer  12 , and the second adhesive layer  14  are changed, and the pattern of the second sub-electrode  24  in the first electrode layer  2  is changed, and the remaining film layers are the same as in the fifth example, and therefore, the details are not repeated here. The first dielectric sub-layer  11  and the third dielectric sub-layer  15  adopt PI substrates with a thickness of 20 um, and Dk/Df is 4.72/0.0047. The second dielectric sub-layer  13  adopts a PET substrate with a thickness of 0.3 mm, and Dk/Df is 3.25/0.0048. The overall size of the micro-wave transducer is 95.7 mm*280 mm. It is realized through a simulation for the above structure that the −6 dB impedance bandwidth of the micro-wave transducer is 1.39 GHz (3.11 GHz to 4.5 GHz); the gain of the micro-wave transducer is 10.21 dBi; the half-power beam width is 14°/69°; and the radiation efficiency of the micro-wave transducer is 69.7%. 
     In a seventh example, a cross-sectional view of the micro-wave transducer is shown in  FIG.  1   , a top view of the micro-wave transducer is shown in  FIG.  9   . This micro-wave transducer is different from the micro-wave transducers in the second to sixth examples, which only lies in the dielectric layer  1 . Specifically, the dielectric layer  1  of the micro-wave transducer is a single-layer PET substrate, and Dk/Df is 3.29/0.0058. The overall size of the micro-wave transducer is 85.1 mm*280 mm. It is realized through a simulation for the above structure that the −6 dB impedance bandwidth of the micro-wave transducer is 1.30 GHz (3.20 GHz to 4.5 GHz); the gain of the micro-wave transducer is 9.82 dBi; the half-power beam width is 14°/83°; and the radiation efficiency of the micro-wave transducer is 65.0%. 
     In an eighth example, a cross-sectional view of the micro-wave transducer is shown in  FIG.  1   , a top view of the micro-wave transducer is shown in  FIG.  9   . This micro-wave transducer is different from the micro-wave transducer in the seventh example, which only lies in the dielectric layer  1 , the radiation patch and the first electrode layer  2 . Specifically, the dielectric layer  1  of the micro-wave transducer adopts a PI substrate with a thickness of 0.2 mm, and Dk/Df of the PI substrate is 3.2/0.004. Both the radiation patch and the first electrode layer  2  adopt copper with a thickness of 18 um. The overall size of the micro-wave transducer is 86.57 mm*280 mm. It is realized through a simulation for the above structure that the −6 dB impedance bandwidth of the micro-wave transducer is 1.17 GHz (3.33 GHz to 4.5 GHz); the gain of the micro-wave transducer is 10.54 dBi; the half-power beam width is 14°/81°; and the radiation efficiency of the micro-wave transducer is 78.8%. 
     In a second aspect, an embodiment according to the present disclosure provides a manufacturing method of a micro-wave transducer, which may be used to manufacture any one of the micro-wave transducers described above. The method specifically includes the following steps: 
     S 1 , providing a dielectric layer. 
     The dielectric layer  1  may be a flexible substrate or a glass substrate, and step S 1  may include a step of cleaning the dielectric layer  1 . 
     S 2 , forming a first electrode layer  2  on a first surface of the dielectric layer  1  through a patterning process. First openings  21  are formed in the first electrode layer  2 . 
     In some examples, step S 2  may specifically include: depositing a first metal film on the first surface of the dielectric layer  1  by adopting a process including but not limited to magnetron sputtering, then coating photoresist, exposing, developing, and then performing wet etching, and striping off the photoresist after etching, to form a pattern including the first electrode layer  2 . 
     S 3 , forming a pattern including transducer electrodes  31  and first microstrip lines  32  on a second surface of the dielectric layer  1  through a patterning process. An orthographic projection of one transducer electrode  31  on the dielectric layer  1  is at least partially overlapped with an orthographic projection of the first opening  21  on the dielectric layer  1 , and preferably the orthographic projection of one transducer electrode  31  on the dielectric layer  1  is within a range defined by the orthographic projection of the first opening  21  on the dielectric layer  1 . Alternatively, in some examples, the transducer electrodes  31  and the first microstrip lines  32  may also be manufactured through two patterning processes. 
     In some examples, step S 3  may specifically include: depositing a second metal film on the first surface of the dielectric layer  1  by adopting a process including but not limited to magnetron sputtering, then coating photoresist, exposing, developing, and then performing wet etching, and striping off the photoresist after etching, to form the pattern including transducer electrodes  31  and first microstrip lines  32 . 
     It should be noted that, the order of the above steps S 2  and S 3  may be interchanged, i.e., the transducer electrodes  31  and the first microstrip lines  32  may be formed on the second surface of the dielectric layer  1 , and then the first electrode layer  2  is formed on the first surface of the dielectric layer  1 , both of which are within the protection scope of the embodiment according to the present disclosure. 
     In some examples, as shown in  FIG.  3   , the dielectric layer  1  in an embodiment according to the present disclosure includes a first dielectric sub-layer  11 , a first adhesive layer  12 , a second dielectric sub-layer  13 , a second adhesive layer  14 , and a third dielectric sub-layer  15 , which are sequentially stacked, wherein a surface of the first dielectric sub-layer  11  away from the first adhesive layer  12  serves as the first surface of the dielectric layer  1 , a surface of the third dielectric sub-layer  1512  away from the second adhesive layer  14  serves as the second surface of the dielectric layer  1 , i.e., the first electrode layer is arranged on a side of the first dielectric sub-layer  11  away from the first adhesive layer  12 , and the transducer electrodes  31  and the first microstrip lines  32  are arranged on a side of the third dielectric sub-layer  15  away from the second adhesive layer  14 . The manufacturing method in the embodiment according to the present disclosure may also be implemented by the following steps. 
     S 11 , providing the first dielectric sub-layer  11 . 
     The first dielectric sub-layer  11  may adopt a PI substrate, and step S 11  may include cleaning the first dielectric sub-layer  11 . 
     S 12 , forming the first electrode layer  2  on the first dielectric sub-layer  11  through a patterning process. First openings  21  are formed on at least one side of the first electrode layer  2 . 
     The step of forming the first electrode layer  2  is the same as step S 2 , and therefore, the details are not repeated here. 
     S 13 , coating the first adhesive layer  12  on a side of the first dielectric sub-layer  11  away from the first electrode layer  2 , forming the second dielectric sub-layer  13  on the first adhesive layer  12 , then forming the second adhesive layer  14  on a surface of the second dielectric sub-layer  13  away from the first adhesive layer  12 , and forming the third dielectric sub-layer  15  on the second adhesive layer  14 . 
     The second dielectric sub-layer  13  may adopt a PET substrate, and the third dielectric sub-layer  15  may adopt a PI substrate. The first adhesive layer  12  and the second adhesive layer  14  may adopt the OCA. 
     S 14 , forming the pattern including the transducer electrodes  31  and the first microstrip lines  32  on the third dielectric sub-layer  15  through a patterning process. An orthographic projection of one transducer electrode  31  on the second dielectric sub-layer  13  is within an orthographic projection of the first opening  21  on the dielectric layer  1 . Alternatively, in some examples, the transducer electrodes  31  and the first microstrip lines  32  may also be manufactured through two patterning processes. 
     The steps of forming the transducer electrodes  31  and the first microstrip lines  32  are the same as those of step S 3 , and therefore, the details are not repeated here. 
     It should be noted that, in the above description, as an example, steps S 1 l to S 13  precede step S 14 , but in the actual process, steps S 14  may be performed firstly, and then the steps S 1 l to S 13  are performed. 
     Referring to  FIG.  4   , the transducer electrodes  31  may also be arranged between the second dielectric sub-layer  13  and the second adhesive layer  14 , and the first electrode layer  2  may also be arranged between the first dielectric sub-layer  11  and the first adhesive layer  12 . The formation method may be similar to the above method, and therefore, the details are not repeated here. 
     In addition, in the embodiment according to the present disclosure, the micro-wave transducer includes the dielectric layer  1 , the first electrode layer  2 , the transducer electrodes  31  and the first microstrip lines  32  formed as described above. The micro-wave transducer may further include the feeding unit  5  formed on the second surface of the dielectric layer  1  and electrically connected to the first microstrip lines  32 . If the feeding unit  5  adopts the above feeding network formed by the second microstrip lines  51 , the feeding unit  5  composed of the second microstrip lines  51  may be formed while the first microstrip lines  32  and the transducer electrodes  31  are formed. 
     It will be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present invention, and the present invention is not limited thereto. It will be apparent to one of ordinary skill in the art that various modifications and improvements can be made without departing from the spirit and scope of the present invention, and such modifications and improvements are also considered to be within the scope of the present invention.