Patent Publication Number: US-9895770-B2

Title: System for automatically inspecting and trimming a patch antenna

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional application of U.S. patent application Ser. No. 13/745,138, filed on Jan. 18, 2013, and entitled “METHOD FOR AUTOMATICALLY INSPECTING AND TRIMMING A PATCH ANTENNA”, which is based on and claims priority from Taiwan Application No. 101101923, filed Jan. 18, 2012. The entire disclosures of the above applications are all incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an antenna, and especially relates to a method and system for automatically inspecting electrical characteristics of a patch antenna and trimming the patch antenna. 
     Description of Related Art 
     A ceramic patch antenna includes a substrate. The substrate includes a radiation metal surface which is at the front side of the substrate, a grounded metal surface which is at the back side of the substrate, and a signal feed-in terminal which is through the substrate and is electrically connected to the radiation metal surface. The first job after a ceramic patch antenna has been manufactured is to inspect whether the electrical characteristics of the ceramic patch antenna are in the standard parameters or not. The inspection mentioned above is essential because different printing sizes of the radiation metal surfaces of the ceramic patch antennas will result in different electrical characteristics. 
     When the ceramic patch antenna is inspected, the ceramic patch antenna is electrically connected to a connector of a radio frequency component testing coaxial cable, so that the electrical characteristics of the ceramic patch antenna are inspected by a testing instrument. Then, a Smith chart of the electrical characteristics will be displayed on the testing instrument. After that, the inspector will check with eyes whether the Smith chart displayed on the testing instrument is the same as the standard parameters or not. If it is not the same, the radiation metal surface of the ceramic patch antenna will be trimmed by the inspector personally with a trimming machine. Once the Smith chart displayed on the testing instrument is the same as the standard parameters, the inspector will stop trimming the radiation metal surface of the panel ceramic antenna. 
     The inspector who trims the radiation metal surface needs a lot of experiences. Moreover, the manufacturing cost is high and the production capacity is low because inspecting and trimming ceramic patch antennas are relied on manpower. 
     SUMMARY OF THE INVENTION 
     In order to solve the above-mentioned problems, an object of the present invention is to provide a method and system for automatically inspecting and trimming a ceramic patch antenna. The electrical characteristics of the ceramic patch antenna will be automatically inspected and trimmed after the ceramic patch antenna has been manufactured, so that the electrical characteristics of the ceramic patch antenna is complied with the standard parameters. Therefore, the ceramic patch antennas are manufactured easier. The manpower and manufacturing cost is lower. The production capacity is higher. The electrical characteristics of the ceramic patch antennas are more accurate. 
     In order to achieve the object of the present invention mentioned above, the method of the present invention is configured to automatically inspect and trim a ceramic patch antenna which has a radiation metal surface. Firstly, an inspection apparatus electrically connected to a radio frequency component testing fixture is arranged. The inspection apparatus is inputted standard parameters of electrical characteristics of the ceramic patch antenna. Then, the ceramic patch antenna is arranged on the radio frequency component testing fixture. The inspection apparatus is configured to measure electrical characteristics of the ceramic patch antenna and to judge whether the electrical characteristics of the ceramic patch antenna are the same as the standard parameters or not. The inspection apparatus is configured to drive a trimming machine for trimming the radiation metal surface of the ceramic patch antenna if the electrical characteristics of the ceramic patch antenna are different from the stand parameters. 
     Moreover, the standard parameters of the electrical characteristics of the ceramic patch antenna are parameters of center frequency, bandwidth, and return loss. The inspection apparatus includes a micro processing unit, a memory unit, an operation interface, and a display. The display is configured to display a Smith chart and an S-parameter curve of the electrical characteristics of the ceramic patch antenna. A position of a middle break point of the Smith chart of the electrical characteristics of the ceramic patch antenna is in a range. A position of a middle break point of the standard parameters is within a lattice displayed on the display. The range is one-third wider extended from the lattice. The middle break point is limited such that a voltage standing wave ratio (VSWR) is larger than one and smaller than infinite. The radio frequency component testing fixture is a radio frequency coaxial cable connector. The radio frequency component testing fixture is electrically connected to a signal feed-in terminal of the ceramic patch antenna. The inspection is finished if the electrical characteristics of the ceramic patch antenna measured by the inspection apparatus are judged the same as the standard parameters. The inspection apparatus is configured to display an image and a location of the radiation metal surface requiring trimming when the electrical characteristics of the ceramic patch antenna are different from the standard parameters. The trimming machine is a laser engraving machine. An image capturing apparatus is configured to capture the image and the location of the radiation metal surface requiring trimming. The inspection apparatus is configured to judge whether the location of the radiation metal surface requiring trimming is correct or not. The trimming machine is calibrated if the location of the radiation metal surface requiring trimming is incorrect. Therefore, the trimming machine is configured to accurately trim the location of the radiation metal surface requiring trimming in accordance with a signal sent from the inspection apparatus. The image capturing apparatus is a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS) camera lens. The inspection and trimming for the ceramic patch antenna is finished if the electrical characteristics of the ceramic patch antenna measured by the inspection apparatus are the same as the standard parameters. 
     In order to achieve the object of the present invention mentioned above, the system of the present invention is configured to automatically inspect and trim a ceramic patch antenna which has a radiation metal surface. The system includes an inspection apparatus and a trimming machine. The inspection apparatus is electrically connected to a radio frequency component testing fixture, wherein the ceramic patch antenna is arranged on the radio frequency component testing fixture. The inspection apparatus is inputted standard parameters. The trimming machine is electrically connected to the inspection apparatus. The ceramic patch antenna is arranged on the radio frequency component testing fixture. The inspection apparatus is configured to measure electrical characteristics of the ceramic patch antenna. The inspection apparatus is configured to drive a trimming machine for trimming a radiation metal surface of the ceramic patch antenna if the electrical characteristics of the ceramic patch antenna are different from the stand parameters. 
     The inspection apparatus includes a micro processing unit, a memory unit, an operation interface, and a display. The micro processing unit has a firmware program for inspecting the electrical characteristics of the ceramic patch antenna. The memory unit is electrically connected to the micro processing unit. The memory unit is configured to record the electrical characteristics of the ceramic patch antenna and the standard parameters. 
     The operation interface is electrically connected to the micro processing unit. The operation interface is adapted to receive commands and parameters. The display is electrically connected to the micro processing unit. The display is configured to display a Smith chart and an S-parameter curve measured by the micro processing unit. 
     A position of a middle break point of the Smith chart of the electrical characteristics of the ceramic patch antenna is in a range. A position of a middle break point of the standard parameters is within a lattice displayed on the display. The range is one-third wider extended from the lattice. The middle break point is limited such that a voltage standing wave ratio (VSWR) is larger than one and smaller than infinite. 
     The radio frequency component testing fixture is a radio frequency coaxial cable connector. The radio frequency component testing fixture is electrically connected to a signal feed-in terminal of the ceramic patch antenna. The standard parameters of the electrical characteristics of the ceramic patch antenna are parameters of center frequency, bandwidth, and return loss. The trimming machine is a grinding engraving machine or a laser machine. The inspection is finished if the electrical characteristics of the ceramic patch antenna measured by the inspection apparatus are the same as the standard parameters. The system further includes an image capturing apparatus electrically connected to the inspection apparatus. The image capturing apparatus is configured to capture the image and the location of the radiation metal surface requiring trimming. Therefore, the trimming machine is configured to accurately trim the radiation metal surface. The image capturing apparatus is a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS) camera lens. 
    
    
     
       BRIEF DESCRIPTION OF DRAWING 
         FIG. 1  shows a flow chart of the method for automatically inspecting and trimming a patch antenna of the present invention. 
         FIG. 2  shows a diagram of the Smith chart of the present invention. 
         FIG. 3  shows a diagram of the radiation metal surface of the ceramic patch antenna of the present invention. 
         FIG. 4  shows another diagram of the Smith chart of the present invention. 
         FIG. 5  shows another diagram of the radiation metal surface of the ceramic patch antenna of the present invention. 
         FIG. 6  shows a block diagram of the system for automatically inspecting and trimming a patch antenna of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a flow chart of the method for automatically inspecting and trimming a patch antenna of the present invention. Firstly, a manufactured ceramic patch antenna is arranged (step  100 ). 
     An inspection apparatus is inputted standard parameters (for examples, parameters of center frequency, bandwidth, and return loss) of electrical characteristics of the ceramic patch antenna. A display of the inspection apparatus is configured to display a Smith chart and an S-parameter curve (step  102 ). The inspection apparatus includes a micro processing unit, a memory unit, an operation interface, and the display. 
     The ceramic patch antenna is arranged on a radio frequency component testing fixture, so that a signal feed-in terminal of the ceramic patch antenna is electrically connected to the radio frequency component testing fixture (step  104 ). The radio frequency component testing fixture is a radio frequency coaxial cable connector electrically connected to the signal feed-in terminal of the ceramic patch antenna. 
     The inspection apparatus is configured to measure electrical characteristics of the ceramic patch antenna and to judge whether the electrical characteristics of the ceramic patch antenna are complied with the Smith chart and the S-parameter curve or not (step  106 ). If the electrical characteristics of the ceramic patch antenna are complied with the standard parameters, the inspection is finished (step  108 ), then the ceramic patch antenna is removed (step  110 ). 
     If the electrical characteristics of the ceramic patch antenna are not complied with the Smith chart and the S-parameter curve, the inspection apparatus is configured to display an image and a location of a radiation metal surface of the ceramic patch antenna requiring trimming (step  112 ). 
     The inspection apparatus is configured to drive a trimming machine for trimming the radiation metal surface (step  114 ). The trimming machine is a laser engraving machine. 
     An image capturing apparatus is configured to capture the image and the location of the radiation metal surface requiring trimming. The inspection apparatus is configured to judge whether the location of the radiation metal surface requiring trimming is correct or not (step  116 ). If the location of the radiation metal surface requiring trimming is incorrect, the trimming machine is calibrated, so that the trimming machine can accurately trim the location of the radiation metal surface. The image capturing apparatus is a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS) camera lens. 
     The inspection and trimming for the ceramic patch antenna is finished if the electrical characteristics of the ceramic patch antenna measured by the inspection apparatus are complied with the Smith chart (i.e. the standard parameters) (step  118 ). 
     Finally, the ceramic patch antenna is removed from the radio frequency component testing fixture (step  120 ). 
       FIG. 2  shows a diagram of the Smith chart of the present invention.  FIG. 3  shows a diagram of the radiation metal surface of the ceramic patch antenna of the present invention. Firstly, the inspection apparatus  1  is inputted the standard parameters of the electrical characteristics of the ceramic patch antenna. The Smith chart  10  is displayed on the display  14  of the inspection apparatus  1 . A position of a middle break point  101  of the Smith chart  20  of the electrical characteristics of the ceramic patch antenna is in a range. A position of a middle break point  101  of the standard parameters is within a lattice displayed on the display  14 . The range is one-third wider extended from the lattice. The middle break point  101  is limited such that a voltage standing wave ratio (VSWR) is larger than one and smaller than infinite (for example, the VSWR is smaller than 1.5 times of the radius). 
     Example 1: when the ceramic patch antenna is inspected, if the frequency is increasing, and the bandwidth is decreasing (or increasing), and the position of the middle break point  101  of the Smith chart  10  is moving up, a right downside  201  and a left upside  201   a  of the radiation metal surface  20  will be trimmed. 
     Example 2: when the ceramic patch antenna is inspected, if the frequency is increasing, and the bandwidth is decreasing (or increasing), and the position of the middle break point  101  of the Smith chart  10  is moving down, a right upside  202  and a left downside  202   a  of the radiation metal surface  20  will be trimmed. 
     Example 3: when the ceramic patch antenna is inspected, if the frequency is increasing, and the bandwidth is increasing (or decreasing), and the position of the middle break point  101  of the Smith chart  10  is moving up, a left side up  203  and a right side down  203   a  of the radiation metal surface  20  will be trimmed. 
     Example 4: when the ceramic patch antenna is inspected, if the frequency is increasing, and the bandwidth is increasing (or decreasing), and the position of the middle break point  101  of the Smith chart  10  is moving down, a right side up  204  and a left side down  204   a  of the radiation metal surface  20  will be trimmed. 
     Example 5: when the ceramic patch antenna is inspected, if the frequency is decreasing, and the bandwidth is increasing (or decreasing), and the position of the middle break point  101  of the Smith chart  10  is not moving, a bottom side  205   a  of a cave  205  of the radiation metal surface  20 , and a bottom side  206   a  of a cave  206  of the radiation metal surface  20  will be trimmed. 
     Example 6: when the ceramic patch antenna is inspected, if the frequency is decreasing, and the bandwidth is decreasing (or increasing), and the position of the middle break point  101  of the Smith chart  10  is not moving, a bottom side  207   a  of a cave  207  of the radiation metal surface  20 , and a bottom side  208   a  of a cave  208  of the radiation metal surface  20  will be trimmed. 
     Example 7: when the ceramic patch antenna is inspected, if the frequency is increasing, and the bandwidth is increasing, and the position of the middle break point  101  of the Smith chart  10  is moving up (or moving down), a corner  209  of the radiation metal surface  20 , and a corner  209   a  of the radiation metal surface  20  will be trimmed. 
     Example 8: when the ceramic patch antenna is inspected, if the frequency is increasing, and the bandwidth is increasing, and the position of the middle break point  101  of the Smith chart  10  is moving up (or moving down), a corner  210  of the radiation metal surface  20 , and a corner  210   a  of the radiation metal surface  20  will be trimmed. 
       FIG. 4  shows another diagram of the Smith chart of the present invention.  FIG. 5  shows another diagram of the radiation metal surface of the ceramic patch antenna of the present invention. Firstly, the inspection apparatus  1  is inputted standard parameters of the electrical characteristics of the ceramic patch antenna. The Smith chart  30  is displayed on the display  14  of the inspection apparatus  1 . A position of a middle break point  301  of the Smith chart  30  of the electrical characteristics of the ceramic patch antenna is in a range. A position of a middle break point  301  of the standard parameters is within a lattice displayed on the display  14 . The range is one-third wider extended from the lattice. The middle break point  301  is limited such that a voltage standing wave ratio (VSWR) is larger than one and smaller than infinite (for example, the VSWR is smaller than 1.5 times of the radius). 
     Example 1: when the ceramic patch antenna is inspected, if the frequency is increasing, and the bandwidth is increasing, and the position of the middle break point  301  of the Smith chart  30  is moving down, a right side up  401  and a left side down  401   a  of the radiation metal surface  40  will be trimmed. 
     Example 2: when the ceramic patch antenna is inspected, if the frequency is increasing, and the bandwidth is decreasing, and the position of the middle break point  301  of the Smith chart  30  is moving down, a right side down  402  and a left side up  402   a  of the radiation metal surface  40  will be trimmed. 
     Example 3: when the ceramic patch antenna is inspected, if the frequency is increasing, and the bandwidth is decreasing, and the position of the middle break point  301  of the Smith chart  30  is moving up, a left upside  403  and a right downside  403   a  of the radiation metal surface  40  will be trimmed. 
     Example 4: when the ceramic patch antenna is inspected, if the frequency is increasing, and the bandwidth is increasing, and the position of the middle break point  301  of the Smith chart  30  is moving up, a right upside  404  and a left downside  404   a  of the radiation metal surface  40  will be trimmed. 
     Example 5: when the ceramic patch antenna is inspected, if the frequency is decreasing, and the bandwidth is decreasing, and the position of the middle break point  301  of the Smith chart  30  is moving down, a bottom side  405   a  of a cave  405  of the radiation metal surface  40  and a bottom side  406   a  of a cave  406  of the radiation metal surface  40  will be trimmed. 
     Example 6: when the ceramic patch antenna is inspected, if the frequency is decreasing, and the bandwidth is increasing, and the position of the middle break point  301  of the Smith chart  30  is moving up, a bottom side  407   a  of a cave  407  of the radiation metal surface  40  and a bottom side  408   a  of a cave  408  of the radiation metal surface  40  will be trimmed. 
     Example 7: when the ceramic patch antenna is inspected, if the frequency is increasing, and the bandwidth is decreasing, and the position of the middle break point  301  of the Smith chart  30  is not moving, a corner  409  of the radiation metal surface  40  will be trimmed. 
       FIG. 6  shows a block diagram of the system for automatically inspecting and trimming a patch antenna of the present invention. The system of the present invention includes an inspection apparatus  1 , a radio frequency component testing fixture  2 , a trimming machine  3 , and an image capturing apparatus  4 . 
     The inspection apparatus  1  is, for example, a computer. The inspection apparatus  1  includes a micro processing unit  11 , a memory unit  12 , an operation interface  13 , and a display  14 . The micro processing unit  11  has a firmware program for inspecting electrical characteristics of a ceramic patch antenna  5 . The memory unit  12  is electrically connected to the micro processing unit  11 . The micro processing unit  11  is configured to record standard parameters of the electrical characteristics of the ceramic patch antenna  5  in the memory unit  12  after the standard parameters of the electrical characteristics of the ceramic patch antenna  5  are inputted into the inspection apparatus  1  through the operation interface  13 . 
     The operation interface  13  is electrically connected to the micro processing unit  11 . The operation interface  13  is adapted to receive commands and parameters. The display  14  is electrically connected to the micro processing unit  11 . The display  14  is configured to display a Smith chart and an S-parameter curve measured by the micro processing unit  11 . The memory unit  12  is, for example, a memory. 
     The radio frequency component testing fixture  2  is a radio frequency coaxial cable connector electrically connected to the inspection apparatus  1 . The ceramic patch antenna  5  is electrically connected to the radio frequency component testing fixture  2 . The radio frequency component testing fixture  2  is configured to send the electrical characteristics of the ceramic patch antenna  5  to the inspection apparatus  1 . The inspection apparatus  1  is configured to read and judge the electrical characteristics of the ceramic patch antenna  5 . 
     The trimming machine  3  is electrically connected to the inspection apparatus  1 . The inspection apparatus  1  is configured to drive the trimming machine  3  for trimming a radiation metal surface  20 ( 40 ) of the ceramic patch antenna  5  if the electrical characteristics of the ceramic patch antenna  5  requires trimming. The trimming machine  3  is a laser engraving machine. 
     The image capturing apparatus  4  is electrically connected to the inspection apparatus. The image capturing apparatus  4  is configured to capture the image and the location of the radiation metal surface requiring trimming. Therefore, the trimming machine  3  is configured to accurately trim the radiation metal surface  20 ( 40 ) of the ceramic patch antenna  5 . The image capturing apparatus  4  is, for example, a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS) camera lens. 
     Firstly, the standard parameters of the electrical characteristics of the ceramic patch antenna  5  are inputted through the operation interface  13 . The ceramic patch antenna  5  is arranged on the radio frequency component testing fixture  2 . A signal feed-in terminal  51  of the ceramic patch antenna  5  is electrically connected to the radio frequency component testing fixture  2 . The electrical characteristics of the ceramic patch antenna  5  are inputted into the inspection apparatus  1 . The ceramic patch antenna  5  is removed from the radio frequency component testing fixture  2  if the electrical characteristics of the ceramic patch antenna  5  are complied with the standard parameters. The inspection apparatus  1  is configured to drive the trimming machine  3  to move above the radiation metal surface  20  ( 40 ) of the ceramic patch antenna  5 . The trimming machine  3  is configured to trim the radiation metal surface  20  ( 40 ) of the ceramic patch antenna  5  in accordance with the result inspected by the inspection apparatus  1 . 
     The image capturing apparatus  4  is configured to capture the image and the location of the radiation metal surface  20  ( 40 ) requiring trimming during the trimming process. Therefore, the trimming machine  3  is configured to accurately trim the radiation metal surface  20 ( 40 ) of the ceramic patch antenna  5 . 
     After the radiation metal surface  20 ( 40 ) of the ceramic patch antenna  5  is trimmed, the inspection is finished if the electrical characteristics of the ceramic patch antenna  5  are complied with the standard parameters. 
     Therefore, the ceramic patch antennas  5  are manufactured easier. The manpower and manufacturing cost is lower. The production capacity is higher. The electrical characteristics of the ceramic patch antennas  5  are more accurate. 
     Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.