Patent Publication Number: US-2023156988-A1

Title: Signal isolation device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to China Application Serial Number 202111339306.6, filed Nov. 12, 2021, which is herein incorporated by reference in its entirety. 
     BACKGROUND 
     Field of Invention 
     The present invention relates to a signal isolation device. 
     Description of Related Art 
     Wireless Wide Area Network (WWAN) has been widely used for many years from the first generation mobile communication to the third generation mobile communication. The fifth generation mobile communication provides Sub-6G frequency band and Wi-Fi 6E frequency band, and Wireless Wide Area Network (WWAN) is unreplaceable. Regardless of whether it is a formal or emergency telephone call, a modem with low bandwidth and low power consumption is still highly demanded. 
     In comparison with Wifi Wireless Local Area Network (WLAN), the frequency bands of Wireless Wide Area Network (WWAN) are mostly at low frequencies which are about 800 MHz˜1.9 GHz in the frequency spectrum. Due to the longer wavelength and larger size of radio frequency components, light and thin products has dominated the evolution trend of consumer electronics products related to smart phones and notebook computers. Therefore, under the limited space, manufactures have to follow the evolution trends, and it is more difficult to design low-frequency radio frequency components. 
     Therefore, how to provide a signal isolation device that is small in size, simple in process, and capable of suppressing signals in multiple frequency bands has become a research target for private enterprises and academic institutions to invest a lot of money, manpower, and time. 
     SUMMARY 
     The invention provides a signal isolation device which includes an insulation layer, at least one metal foil unit, and a metal layer. The at least one metal foil unit is disposed on a top surface of the insulation layer, and the metal foil unit has a first recessed channel and a second recessed channel. The first recessed channel and the second recessed channel spirally extend inward from an edge of the metal foil unit, and the first recessed channel and the second recessed channel surrounding each other are spaced apart. The metal layer is disposed on a bottom surface of the insulation layer. 
     In some embodiments of the present invention, the metal foil unit is square, and the first recessed channel and the second recessed channel extend from two opposite sides of the metal foil unit respectively. 
     In some embodiments of the present invention, the first recessed channel has a straight middle portion disposed between a straight head portion and a straight tail portion of the second recessed channel. 
     In some embodiments of the present invention, the second recessed channel has a straight middle portion disposed between a straight head portion and a straight tail portion of the first recessed channel. 
     In some embodiments of the present invention, the first recessed channel and the second recessed channel have a plurality of vertical bending portions. 
     In some embodiments of the present invention, the first recessed channel and the second recessed channel are in a rotational symmetry around a center of the metal foil unit. 
     In some embodiments of the present invention, the first recessed channel has a width equal to a width of the second recessed channel. 
     In some embodiments of the present invention, a width of the first recessed channel is from 0.8 mm to 1.2 mm. 
     In some embodiments of the present invention, the first recessed channel has a portion immediately adjacent to and spaced apart from a portion of the second recessed channel by a minimum distance from 0.8 mm to 1.2 mm. 
     In some embodiments of the present invention, the signal isolation device further includes additional metal foil units which are immediately adjacent to the metal foil unit and arranged along a row. 
     In embodiments of the present invention, a signal isolation device is provided, and the signal isolation device includes a single layer board structure. The signal isolation device has outstanding signal isolation ability in various frequency bands with a simple structure. Users can easily adjust the length of the recessed channel in the metal foil of the signal isolation device, and the signal isolation device can provide isolation functions in low frequency bands. 
     An aspect of the present invention provides a signal isolation device including an insulation layer, a plurality of metal foil units, and a metal layer. The plurality of metal foil units disposed on a top surface of the insulation layer, and each of the metal foil units has a first recessed channel and a second recessed channel. The first recessed channel and the second recessed channel spirally extend inward from an edge of the metal foil unit toward a center of the metal foil unit, and the first recessed channel and the second recessed channel surrounding each other are spaced apart. The metal layer is disposed on a bottom surface of the insulation layer. 
     An aspect of the present invention provides a signal isolation device including an insulation layer, a plurality of metal foil units, and a metal layer. The plurality of metal foil units are disposed on a top surface of the insulation layer, and one of the metal foil units is in direct contact with another one of the metal foil units. Each of the metal foil units has a first recessed channel and a second recessed channel, and the first recessed channel and the second recessed channel spirally extend inward from an edge of the metal foil unit. The first recessed channel and the second recessed channel surrounding each other are spaced apart. The metal layer is disposed on a bottom surface of the insulation layer. 
     It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: 
         FIG.  1    illustrates a schematic view of a signal isolation device in accordance with some embodiments of the present invention. 
         FIG.  2    illustrates a top view of the signal isolation device in accordance with some embodiments of the present invention. 
         FIG.  3    illustrates a top view of the signal isolation device in accordance with some embodiments of the present invention. 
         FIG.  4    illustrates a comparison diagram of return loss of the signal isolation device in accordance with some embodiments of the present invention. 
         FIG.  5    illustrates a signal isolation device in accordance with some other embodiments of the present invention. 
         FIG.  6    illustrates a comparison diagram of return loss of the signal isolation devices in accordance with some embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
     Please refer to  FIGS.  1  and  2   .  FIG.  1    illustrates a schematic view of a signal isolation device  100 .  FIG.  2    illustrates a top view of the signal isolation device  100 . In some embodiments of the present invention, the signal isolation device  100  includes an insulation layer  110 , a metal foil unit  130 , and a metal layer  150 . The metal foil unit  130  is disposed on a top surface of the insulation layer  110 , and the metal foil unit  130  includes a first recessed channel  131   a  and a second recessed channel  131   b.  The first recessed channel  131   a  and the second recessed channel  131   b  extend from an edge  133  of the metal foil unit  130  to extend spirally inward toward a center C of the metal foil unit  130 . The first recessed channel  131   a  and the second recessed channel  131   b  which extend through the metal foil unit  130  expose the top surface of the insulation layer  110 , and the first recessed channel  131  and the second recessed channel  131   b  which are separated surround each other. Moreover, the metal layer  150  is disposed on a bottom surface of the insulation layer  110 , and the first recessed channel  131   a  and the second recessed channel  131   b  of the metal foil unit  130  form path features which is benefit for providing outstanding isolation abilities to the signal isolation device  100  in many frequency bands. 
     In some embodiments of the present invention, the insulation layer  110  can be a printed circuit board (PCB), and the insulation layer  110  can be a printed circuit board in FR4 printed circuit board specification. In addition, the metal foil unit  130  and the metal layer  150  can be made of copper or copper alloy, and the first recessed channel  131   a  and the second recessed channel  131   b  of the metal foil unit  130  can be manufactured by an etching process, a laser cutting process, or a machining process. The present invention is not limited n this respect. 
     In some embodiments of the present invention, the insulation layer  110  is in rectangular shape such as square shape, and the metal foil unit  130  is rectangular or square. The first recessed channel  131   a  and the second recessed channel  131   b  extend from two opposite sides or corners of the metal foil unit  130  respectively to extend spirally inward toward a center C of the metal foil unit  130 , and the first recessed channel  131   a  and the second recessed channel  131   b  are in a rotational symmetry around a center C of the metal foil unit  130 . The present invention is not limited in this respect. 
     In some embodiments of the present invention, the first recessed channel  131   a  includes a straight head portion H 1 , a straight middle portion M 1 , and a straight tail portion T 1 , and the second recessed channel  131   b  also includes a straight head portion H 2 , a straight middle portion M 2 , and a straight tail portion T 2 . The straight middle portion M 1  communicates between the straight head portion H 1  and the straight tail portion T 1 . The straight middle portion M 2  communicates between the straight head portion H 2  and the straight tail portion T 2 . Moreover, the straight middle portion M 1  of the first recessed channel  131   a  is disposed between the straight head portion H 2  of the second recessed channel  131   b  and the straight tail portion T 2 , so the straight head portion H 2  and the straight tail portion T 2  of the second recessed channel  131   b  are respectively disposed at two opposite side of the straight middle portion M 1  of the first recessed channel  131   a.  In addition, the straight middle portion M 2  of the second recessed channel  131   b  is disposed between the straight head portion H 1  and the straight tail portion T 1  of the first recessed channel  131   a,  so the straight head portion H 1  and the straight tail portion T 1  of the first recessed channel  131   a  are respectively disposed at two opposite sides of the straight middle portion M 2  of the second recessed channel  131   b.  The present invention is not limited in this respect. 
     In one or more embodiments of the present invention, the first recessed channel  131   a  includes a plurality of vertical bending portion B 1  and a plurality of straight portion S 1 , in which the vertical bending portions B 1  and the straight portions S 1  enable the first recessed channel  131   a  to form a rectangular spiral pattern. For instance, the first recessed channel  131   a  includes four vertical bending portions B 1  and five straight portions S 1 , and each of the vertical bending portions B 1  is disposed between two adjacent ones of the straight portions S 1 . The second recessed channel  131   b  includes a plurality of vertical bending portions B 2  and a plurality of straight portions S 2 , and the vertical bending portions B 2  and the straight portions S 2  are alternately arranged such that the second recessed channel  131   b  to form a rectangular spiral pattern. For instance, the second recessed channel  131   b  includes four vertical bending portions B 2  and five straight portions S 2 , and each of the vertical bending portions B 2  is disposed between two adjacent ones of the straight portions S 2 . The present invention is not limited in this respect. 
     In some embodiments of the present invention, the first recessed channel  131   a  has a first width W 1  equal to a second width W 2  of the second recessed channel  131 , and the first width W 1  of the first recessed channel  131   a  is from about 0.8 mm to about 1.2 millimeters (mm). For instance, the first width W 1  of the first recessed channel  131   a  is about 1 mm. In addition, the second recessed channel  131   b  has a second width W 2  from about 0.8 mm to about 1.2 mm. For instance, the second width W 2  of the second recessed channel  131   b  is about 1 mm. The present invention is not limited in this respect. When the first width W 1  of the first recessed channel  131   a  and/or the second width W 2  of the second recessed channel  131   b  are from about 0.8 mm to 1.2 mm, the signal isolation device  100  has outstanding isolation ability in various frequency bands. In some embodiments of the present invention, a portion of the first recessed channel  131   a  is immediately adjacent to and spaced apart from a portion of the second recessed channel  131   b  by a minimum distance D from about 0.8 mm to about 1.2 mm. For instance, the straight head portion H 1  of the first recessed channel  131   a  is immediately adjacent to and spaced apart from the straight middle portion M 2  of the second recessed channel  131   b  by a minimum distance D from about 0.8 mm to about 1.2 mm, and the straight head portion H 1  and the straight middle portion M 2  are parallel to each other. In some other embodiments of the present invention, the first width W 1  of the first recessed channel  131   a  is different from the second width W 2  of the second recessed channel  131   b.  The present invention is not limited in this respect. 
     Reference is made to  FIG.  3   . In some embodiments of the present invention, the signal isolation device  100  further includes a plurality of the metal foils units  130 , such as three metal foil units  130 , and the metal foil units  130  are sequentially immediately adjacent to each other in a row along an axis X. The present invention is not limited in this respect. Specifically, the first recessed channels  131   a  and the second recessed channels  131   b  of the metal foil units  130  do not communicate with each other. Specifically, two immediately adjacent ones of the metal foil units  130  are in mirror symmetry. In some other embodiments of the present invention, one of the metal foil units  130  is in direct contact with another one of the metal foil units  130 . The present invention is not limited in this respect. 
     Reference is next made to  FIG.  4   , which illustrates a comparison diagram of return loss of the signal isolation device  100 , and a curved line A 1  in  FIG.  4    shows that the S Parameters of the signal isolation device  100  are below −40 dB in various frequency bands. For instance, the S Parameters corresponding to the frequency bands from 800 MHz to 1 GHz, from 2.4 GHz to 2.5 GHz, from 3.55 GHz to 3.7 GHz, and from 5.15 GHz to 5.85 GHz, are below −40 dB, and thus the signal isolation device  100  has outstanding signal isolation abilities in various frequency bands. 
     Reference is made to  FIG.  5   , which illustrates a top view of a signal isolation device  100 A. The signal isolation device  100 A is substantially the same as the signal isolation device  100 , and a major difference between the signal isolation device  100  and the signal isolation device  100 A is that the first recessed channel  131   a  of the signal isolation device  100 A is closer to the center C than the first recessed channel  131   a  of the signal isolation device  100 . In addition, the first recessed channel  131   a  of the signal isolation device  100 A has an overall length greater than an overall length of the first recessed channel  131   a  of the signal isolation device  100 . Moreover, the second recessed channel  131   b  of the signal isolation device  100 A is closer to the center C of the second recessed channel  131   b  of the signal isolation device  100 , and thus the second recessed channel  131   b  of the signal isolation device  100 A has an overall length greater than an overall length of the second recessed channel  131   b  of the signal isolation device  100 . The present invention is not limited in this respect. Specifically, the first recessed channel  131   a  of the signal isolation device  100 A includes eight vertical bending portions B 1  and nine straight portions S 1 , and each of the vertical bending portions B 1  is disposed between two adjacent ones of the straight portions S 1 . The second recessed channel  131   b  includes eight vertical bending portions B 2  and nine straight portions S 2 , and each of the vertical bending portions B 2  is disposed between two adjacent ones of the straight portions S 2 . The present invention is not limited in this respect. 
     Reference is made to  FIG.  6   , which illustrates comparison diagram of return loss of the signal isolation device  100  and the signal isolation device  100 A, and the curved line A 1  and the curved line A 2  can respectively represent the signal isolation device  100  and the signal isolation device  100 A. According to  FIG.  6   , in comparison with the signal isolation device  100 , the signal isolation device  100 A can provide signal isolation function in lower frequency bands, and the first recessed channel  131   a  and the second recessed channel  131   b  of the signal isolation device  100  can be broadened and lengthened to form the signal isolation device  100 A by a laser cutting process or an etching process. As can be known, the signal isolation device  100 A in the present invention can be manufactured by easy processes, so as to adjust the signal isolation abilities thereof. 
     In embodiments of the present invention, a signal isolation device is provided, and the signal isolation device includes one single layer structure. The signal isolation device has outstanding signal isolation abilities in various frequency bands with a simple structure. Users can easily adjust the length of the recessed channel in the metal foil of the signal isolation device, and the signal isolation device can provide isolation functions in low frequency bands. 
     Although the present invention has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims.