TWI327786B - An emc internal meandered loop antenna for multiband operation - Google Patents

Description

1327786 VIII. If there is a chemical formula in this case, please disclose the chemical formula that best shows the characteristics of the invention. IX. Description of the invention: [Technical field of the invention] The present invention is a mobile communication antenna, in particular, having electromagnetic compatibility characteristics. Tibetan multi-frequency 蜿蜒 loop antenna. [Prior Art]

In recent years, with the rapid development of mobile communications, built-in antennas for mobile devices have been required to have multi-frequency operation characteristics. In order to achieve multi-frequency operation, many inverted F-shaped antennas (PIFA, Planar Inverted-F Antenna) The structure has been researched and designed and applied to wireless communication products such as mobile phones. However, the resonant modes excited by the inverted-F antenna of this type of multi-frequency operation belong to the unbalanced mode. Compared with the excited mode of the self-balanced structure, the excited mode of this type of unbalanced structure will This results in a large surface excitation current on the system ground plane, so when the lossy medium (such as a person's hand and head) is close to the mobile phone, the antenna characteristics will be greatly deteriorated and can be expected. In order to achieve the characteristics of a self-balancing structure, many designed full-wavelength loop antennas have also been studied and actually applied to mobile phones. The design of the related conventional antenna is as described in U.S. Patent No. 6,958,737, which is incorporated herein by reference in its entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire

"Mobile Terminal Capable of Reducing Specific Absorption Rate"'' and U.S. Patent No. 6,236,368, "Loop Antenna Assembly For Telecommunication Devices", which disclose a loop antenna However, the loop antenna of the above patent has only the characteristics of single frequency operation, and cannot meet the requirements of multi-frequency operation of the current mobile communication device, and cannot be too close to the possible conductor elements inside the mobile device, resulting in the space being unable to be effectively utilized. The antenna of the present invention can adjust the frequency ratio of the first three resonant modes of the antenna by appropriately circling the radiator, thereby achieving the purpose of multi-frequency operation, and simultaneously integrating an antenna ground plane as a shield metal wall. The concept can effectively block or substantially reduce the possible coupling effects between the antenna and the associated conductor elements, thus improving the disadvantages of the conventional loop antennas which mostly have only single frequency operation and cannot be too close to possible conductor elements inside the mobile device. In addition, the antenna can be separated by a part of the loop radiator The edge of the grounding surface of the system is used to effectively increase the impedance bandwidth of the antenna. SUMMARY OF THE INVENTION As described above, an object of the present invention is to provide a built-in multi-frequency loop antenna having electromagnetic compatibility characteristics. To meet the requirements of current mobile communication devices. The present invention includes: a system ground plane; an antenna ground plane; a loop of radiating metal sheets; a shorted metal strip; and a feed signal component. Having a starting end and an end, substantially perpendicular to the ground plane of the antenna, and substantially parallel to the ground plane of the system 8 1327786 square, and the loop radiates a part of the surface of the metal sheet, the edge, and includes a - radiating portion ::The first:m also the second radiation part; one of the short-circuited metal pieces. The tan and the metal piece are too electrically connected to the loop and the radiation is fed to::::=the antenna is grounded" A two-terminal electric milk including a feed signal source is connected to a start end of the loop radiation metal sheet, and an end is connected to the feed signal source. 〃 In the outline meter, the first radiation part is long straight Gold == piece, its - For the loop, the starting end of the metal sheet is lightly irradiated. The second portion is also a long straight metal strip, and is substantially bilaterally symmetric with the first radiating portion on both sides of the loop radiating metal sheet, and the first The end of the two-shot portion radiates the end of the metal piece of the loop. The third radiating portion is formed of a metal frit (4) and has a starting end and an end, and the starting end is connected to the first radiating portion. Irradiating the other end of the starting end of the metal sheet with respect to the loop, the end extending substantially in a meandering manner in a direction opposite to the starting end, and connected to the second radiating portion to radiate the metal sheet relative to the loop The other end of the end. [Embodiment] The first embodiment of the present invention is a built-in type of loop antenna, including: system ground plane 10; - antenna ground plane 11; a loop of radiating metal sheet 12 having a starting end 121 and an end 122, substantially perpendicular to the antenna ground plane U' and substantially parallel to the system ground plane 1 327 9 1327786 ' and the portion of the loop radiating metal sheet 12 protrudes from one of the system ground plane edges 101 and includes a first radiant portion, a second radiating portion 14 and a third radiating portion 15, the first radiating portion 13 is substantially a long straight metal thin piece, and one end of the loop is a light-emitting metal sheet 12 The starting end 121, the second light-emitting portion 14 is also substantially a long straight metal, a 'field piece, and is substantially bilaterally symmetric with the first radiating portion 13 on both sides of the loop light-emitting metal sheet 12, and One end of the second radiating portion 14 is the end 122 of the loop radiating metal piece 12, and the third radiating portion 15 is formed by a uniform metal thin piece and has a starting end 151 and an end end 152. The starting end 151 is connected to the first radiating portion 13 with respect to the loop The other end 131 of the starting end 121 of the metal sheet 12 is radiated, and the end 152 extends in a meandering manner substantially in a direction opposite to the starting end 151, and is connected to the second Korean portion 14 to radiate relative to the loop. The other end 141 of the end 122 of the metal piece 12; a shorted metal piece 16 having one end electrically connected to the end 122 of the retroreflective metal piece 12 and the other end electrically connected to the antenna ground plane, the shorted metal piece 15 and having a uniform line width '· and a feed signal component between the antenna ground plane 丨丨 and the loop radiating metal piece 12, including a feed signal source 17 and a feed metal sheet ,8, The feed metal piece 18 is electrically connected to the starting end 121 of the loop radiating metal piece 12, and the other end is connected to the feed signal source 17, which feeds the metal piece 18 and has a uniform line width. 2A is a top view of a conventional loop antenna having a resonant mode (half wavelength mode 21, full wavelength mode 22, and L5 wavelength mode 23) having a frequency ratio of approximately 1:2. :3, as shown in Figure 2B, back to the 1327786 back loss test measurement results.

Fig. 3 is a graph showing the results of the experimental measurement of the return loss of one embodiment of the antenna of the present invention. In this embodiment, the system ground plane (7) has a length of about 100 mm and a width of about 6 mm; the equivalent length of the loop radiating metal sheet 2 is close to a half wavelength of 9 GG MHz. * radiating the metal piece 12 by the loop, the third resonant mode 33 of the loop antenna (15 wavelength mode is adjusted to be very close to the second resonant mode Μ 1 full wavelength Mode), which in turn forms a wide frequency operation in the high frequency band. The experimental results obtained from actual measurements, under the definition of return loss less than 7 ground, the antenna impedance bandwidth can cover the tri-band operation requirements of the wireless mobile communication system gSM. Figure 4 is the experimental results of the return loss of the shielded metal box of the RF circuit module. The parameters of the antenna are the same as those of the antenna. The length of the shielded metal box 41 of the RF circuit module is about Is 4. With a width of about 6. With a height of about 6 legs. The return loss curve 43 obtained in the case where the shield metal case 41 is disposed (directly contacting the antenna ground plane u) is almost overlapped with the return loss curve 42 in the case where the shield metal case 41 is not disposed. , = the antenna impedance bandwidth is not significantly changed due to the placement of the RF circuit module shielding gold 'that is, the antenna is not affected by the group shielding metal (four), even #RF circuit module box! When directly contacting the antenna ground plane 11, the antenna is still required for bipedal operation. 11 1327786 FIG. 5 is a plan view showing a first embodiment of the electromagnetic compatibility built-in multi-frequency loop antenna of the present invention, wherein the third radiating portion 55 of the loop radiating metal sheet 12 is unevenly The hook metal thin # is made of the same, and the loop radiating metal piece 12, the short-circuited metal piece % and the feed metal piece 18 are formed on the microwave substrate by printing or (4) technology. Figure 6 is a plan view showing a second embodiment of the electromagnetic compatibility built-in multi-frequency loop antenna of the present invention, wherein the short metal sheet 66 and the feed gold

The ply 68 is an uneven sentence line width. Two other embodiments of Figures 5 and 6 are: to achieve electromagnetic phase and multi-frequency operation characteristics similar to the embodiment of Figure 1 of the present description. The embodiments described are merely illustrative of the principles and the teachings of the invention. Therefore, those skilled in the art can modify and change the above embodiments without departing from the spirit of the invention. The rights and scope of the present invention are as set forth in the patent scope below.

12 U27786 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a top view of an embodiment of the present invention. The figure is a structural view in which the antenna of Fig. 1A is expanded into a plane. Fig. 1c is a side view showing an embodiment of the present invention. Figure 2A is a top view of a conventional loop antenna. Figure 2B is a graph showing the return loss measurement results of a conventional loop antenna. Figure 3 is a graph showing the return loss measurement of an embodiment of the antenna of the present invention.

Figure 4 is a graph showing the return loss measurement results of an embodiment of an antenna of the present invention in the case of arranging a shielded metal box of a neighboring RF circuit module. Figure 5 is a plan development view of a first other embodiment of the present invention. Figure 6 is a plan development view of a second other embodiment of the present invention.

13 1327786 [Description of main component symbols] 10: System ground plane 101: One of the system ground plane edges 11: Antenna ground plane 12: Loop radiation metal sheet 121: Starting end of the loop radiation metal sheet 122: Loop radiation metal sheet End 13 • The first radiating portion of the metal sheet of the revolving metal sheet 131: the other end 14 of the first radiating portion with respect to the starting end 121 of the radiating metal sheet: the second radiating portion 141 of the loop radiating the metal sheet · The second radiating portion is opposite to the other end 15 of the end 122 of the metal sheet of the loop, 55. The third rotating portion 151 of the loop light metal sheet: the third radiating portion of the loop metal sheet Start • I52 : End of the third radiating part of the loop radiating metal piece 16,66: Short-circuited metal piece 17 : Feeding signal source 18, 68 ··Feeding metal piece 2〇: Conventional loop radiation metal piece 21,31 Brother-resonance mode 22, 32 · first resonance mode 23, 33 • third resonance mode 41: RF circuit module shielded metal case 1327786

42: Return loss curve before configuring the RF circuit module shielding metal box 43: Return loss curve after configuring the RF circuit module shielding metal box (directly contacting the antenna ground plane) 51: Microwave substrate 15

Claims (1)

1327786 十五傲更) is replacing g. Patent application scope: A built-in multi-frequency loop antenna of electromagnetic phase valley, comprising: a system ground plane; antenna ground plane, substantially vertical and electrically connected to the system ground plane a loop of light metal sheet having a starting end and an end substantially perpendicular to the ground plane of the antenna and substantially parallel to the ground plane of the system, and a portion of the loop of the light-emitting metal dome protrudes from the system One edge of the ground plane, and comprising: the Koda field spout P' is substantially a long straight metal piece, one end of which is the starting end of the loop radiating metal piece; the second radiating part is substantially long a metal thin piece, which is substantially bilaterally symmetric with the first Kodak shot, located on the loop light metal sheet=both sides and the end of the second radiating portion is the end of the loop light metal sheet; The projection portion is formed of a metal thin piece and has a starting end and an end end connected to the first spoke. The opposite end of the radiating metal piece relative to the loop is: the end is substantially away from the end The start The direction of the bowl is "square; extended, and connected to the second radiant part of the eye. The other end of the metal sheet is for the loop. The loop 辐 ^ is connected to the side antenna ground plane; and the feed 彳 § component is located at the grounding surface of the 仏 仏 天线 antenna and the loop radiating gold 16 genus gate includes a feed signal source and a feed The metal piece is fed into the metal piece, and the end is electrically connected to the beginning end of the loop metal piece, and the other end is connected to the feed signal source. The built-in type of the first item of the patent application scope The loop antenna, the funnel radiating metal piece is substantially symmetrical. For example, the built-in loop antenna of the i-th patent scope, the antenna ground plane, the loop radiating metal piece, the short-circuit metal piece and The feed piece is made of a metal piece by stamping or cutting technology. The Shenshen = monthly patent range of the first hidden loop antenna, the loop radiates the metal piece, the shorted metal piece and The feed metal sheet is stamped or cut by a metal The inner loop type loop antenna of the first application patent scope, the loop radiation metal sheet, the short-circuit metal sheet and the feed metal sheet are formed on a microwave substrate by printing or engraving technology. .