TWI241742B - A broadband digital TV receiving antenna - Google Patents

Abstract

The present invention is related to an antenna suitable for digital television signal reception. The antenna comprises a ground plane, a planar radiating metal plate above an edge of the said ground plane, and a feeding coaxial cable for transmitting signals. The said planar radiating metal plate includes a feeding point and several slits. The present invention is suitable for UHF (470-806 MHz) band operation, and shows good omnidirectional radiation in the azimuthal plane.

Description

1241742 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a broadband antenna suitable for digital television reception, particularly an antenna for wireless communication products such as notebook computers. [Prior art]

With the rapid development of wireless communication, the application of wireless products has become more and more widespread. Now we can easily receive TV signals in places with good communication through portable TVs and other products. However, the current application Antennas for portable TVs or TVs that are generally used indoors are mostly rod-type designs, such as US Patent Nos. 5,552,796, 357,022, and 371,796. Since the antenna structure of this rod-type design is a monopole wire antenna, not only its bandwidth is narrow (generally less than 10%), but also its height needs to be approximately 0.25 of the center frequency of the operating band when in use. Around the wavelength, if the UHF band used

(470-806 MHz) to calculate the center frequency, the antenna height needs approximately 120 mm, this height is less beautiful and inconvenient during use. In order to improve the problem of its narrow bandwidth and high height, we propose an innovative design of a wideband antenna for retractable digital TV reception, which can effectively make the height of the antenna less than 0.1 operating wavelength, that is less than 50 mm. This can make the antenna more beautiful in use, and due to its telescopic structure, the antenna can be completely contained in the product when not in use. In addition, the antenna of the present invention may have a bandwidth (defined as 2.5: 1 VSWR) of more than 250 MHz, which can cover most of the U H F digital television frequency band operation.

Page 9 1241742 V. Description of the invention (2) [Summary of the invention] As mentioned above, the object of the present invention is to provide an innovative design of a broadband antenna suitable for digital television reception. The antenna of the present invention includes: a ground plane including a ground point; a flat light-emitting metal piece located above an edge of the ground plane and extending in the opposite direction of the ground plane, and its shape is roughly one with two truncated angles Rectangular, and the two truncated corners face the ground plane, and the planar radiating metal sheet has a feed point and a plurality of slits, wherein each of the plurality of slits has a starting end and an end, and the starting end is located at One edge of the radiating metal sheet, the end extending toward the inside of the radiating metal sheet, and the plurality of slits are parallel to each other, and the extending directions of two adjacent slits are opposite to each other; and a feeding coaxial A transmission line for transmitting a signal includes: a center wire connected to the feed point of the planar radiating metal sheet; and an outer ground conductor connected to the ground point of the ground plane. In this design, we can embed the appropriate number and length of slits to obtain the operating mode we need, and use this technology to achieve the purpose of reducing the antenna; The size of the angle is used to get a good match and a wide band operation. From the above characteristics, we can design antennas suitable for digital TV U H F band reception. [Embodiment] Referring to the first figure, a digital television receiving antenna according to an embodiment 1 of the present invention includes: a ground plane 10, including a ground point 1 0 1;-planar radiating metal

Page 101241742 V. Description of the invention (3) The sheet 12 is located above one of the edges 10 of the ground plane 10 and extends in the opposite direction of the ground plane 10. Its shape is roughly one with two truncated corners Rectangular, and the two truncated corners face the ground plane 10, and the planar radiating metal sheet 12 has a feed point 121 and three slits (13, 14, and 15), and the slit 13 has a starting end 131 And an end 132, the starting end 131 is located on an edge of the radiating metal sheet 12, and the end 1 3 2 extends toward the inside of the radiating metal sheet 12; the slit 14 has a starting end 141 and an end 1 4 2 The starting end 1 4 1 is located at an edge of the radiating metal sheet 12, the end 1 4 2 extends toward the inside of the radiating metal sheet 12, and the slits 14 and the slit 13 extend in the direction The slits 15 have a starting end 151 and an end 152, the starting end 151 is located on one edge of the radiating metal sheet 12, and the end 1 5 2 is facing the inside of the radiating metal sheet 12 Extending, and the extending directions of the slit 15 and the slit 14 are opposite to each other; and A shaft transmission line 16 for transmitting signals includes: a center wire 16 1 connected to the feed point 1 2 1 of the planar radiating metal sheet; and an outer ground conductor 1 6 2 connected to the ground plane 1 0 的 此 地点 1 0 1. In the first embodiment, the planar radiation metal sheet 12 is made by stamping or cutting on a single metal sheet. Figure 2 shows the measurement results of the return loss experiment of the antenna of the first embodiment of the present invention. In the first embodiment, in order to simulate the ground metal surface environment built into the LCD screen of a notebook computer, we choose the ground surface 10 to have a length of about It is 280 mm and the width is about 200 mm; the slit 13 of the planar radiation metal sheet 12 has a length of about 15 mm and a width of 2 mm; the planar radiation metal sheet 12 has

Page 11 1241742 V. Description of the invention (4)

The slit 14 has a length of about 37.5 mm and a width of 2 mm; the slit 15 of the planar radiating metal sheet 12 has a length of about 44 mm and a width of 2 mm; the feed point 1 2 1 and the The distance between the ground points 1 0 1 is 2 mm. From the obtained experimental results, under the definition that the return loss is less than 7.3 dB or 2.5: 1 VSWR, before there is no slit, the minimum frequency h and the maximum frequency fu of the impedance bandwidth are 5 5 1 Μ Η z and 1 3 5 5 Μ Η z, will not be able to cover the frequency band of TV signal reception, so we use a buried slot to effectively extend the current path, so that the lowest frequency I and the highest frequency f of the impedance bandwidth can be reduced to the digital television signal The UHF frequency band further reduces the size of the antenna. When the slot 1 3, the slot 14 and the slot 15 are buried, the minimum frequency I and maximum frequency fu of the impedance bandwidth are reduced to 48, respectively. 0 MHz and 7 4 2 Μ Η z (see Table 1), and this operating mode 2 1 (see Figure 2) can roughly cover the frequency band of TV signal reception. Table 1: Results of measuring bandwidth of an embodiment of the antenna of the present invention.

Number of buried slits Λ (MHz) / υ (MHz) / c (MHz) BW (MHz) BW (%) 0 551 1355 953 804 84 la 540 1295 918 755 82 2b 525 860 693 335 48 3C 480 742 611 262 43 a: embed the slit 13. b: embed the slit 13 and the slit 14. c: embed the slit 13, the slit 14 and the slit 15. Page 12 1241742 5. Description of the invention (5) Figure 3 is a radiation field pattern of the antenna according to the first embodiment of the present invention. The horizontal plane radiation field pattern is nearly omnidirectional, which is quite suitable for practical applications. FIG. 4 is a gain diagram of the antenna according to the first embodiment of the present invention. In the U H F digital video band, the gain is about 1.5 to 2.2 dB i, which is suitable for the gain requirements of practical applications.

FIG. 5 is a structural diagram of another embodiment of a radiating metal sheet of an antenna according to the present invention. This embodiment 5 includes: a planar radiating metal sheet 52, which is substantially triangular in shape, and the planar radiating metal sheet 52 has a feed-in. Point 521 and 4 slits (53, 54, 55, and 56). The slit 53 has a start end 531 and an end 532. The start end 531 is located on one edge of the radiating metal sheet 52, and the end 5 3 2 is The slit 54 has a starting end 541 and an end 542. The starting end 541 is located at an edge of the radiating metal sheet 52, and the end 5 4 2 faces the radiating metal sheet. 5 2 extends internally, and the extending directions of the slit 54 and the slit 53 are opposite to each other; the slit 55 has a starting end 551 and an end 552, and the starting end 551 is located on the radiating metal sheet 52 An edge, the end 5 5 2 extends toward the inside of the radiating metal sheet 5 2, and the extending directions of the slit 55 and the slit 54 are opposite to each other; the slit 5 6 has a starting end 561 and an end 562, the starting end 561 is located on the radiating metal sheet 5 2 An edge of the end 562 toward the interior of the radiating metal plate 52 of the extension, and the slit 56 and the slit 55 extending in the direction of the directions opposite to each other. In the fifth embodiment, the planar radiation metal sheet 52 is stamped or cut from a single metal sheet.

Page 131241742 V. Description of the invention (6) Figure 6 is a structural diagram of another embodiment of the radiating metal sheet of the antenna of the present invention. This embodiment 6 includes a planar radiating metal sheet 62, which is approximately trapezoidal in shape. The planar radiating metal sheet 62 has a feeding point 6 2 1 and two slits (63 and 64). The slit 63 has a starting end 631 and an end 632. The starting end 631 is located on the radiating metal sheet 62. One of the edges, the end 6 3 2 extends toward the inside of the radiating metal sheet 62; the slit 64 has a starting end 641 and an end 642, and the starting end 641 is located on one edge of the radiating metal sheet 62; The end 6 4 2 extends toward the inside of the radiating metal sheet 62, and the extending directions of the slit 64 and the slit 63 are opposite to each other. In the sixth embodiment, the planar radiation metal sheet 62 is formed on a microwave substrate 62 by a printing or etching technique. FIG. 7 is a structural diagram of another embodiment of a radiating metal sheet of an antenna of the present invention. This embodiment 7 includes: a radiating metal sheet 72 having a bend 7 2 2 so that the radiating metal sheet forms an inverted L shape. The radiation metal sheet 7 2 has a feed point 721 and three slits (73, 74, and 75). The slit 73 has a starting end 731 and an end 732. The starting end 731 is located on the radiation metal sheet 7 2 One end, the end 7 3 2 extends toward the inside of the radiating metal sheet 7 2; the slit 74 has a start end 741 and an end 742, and the start end 741 is located on an edge of the radiating metal sheet 72, the end 742 extends toward the inside of the radiating metal sheet 72, and the extending directions of the slit 74 and the slit 73 are opposite to each other; the slit 75 has a starting end 751 and an end 752, and The starting end 751 is located at one edge of the radiating metal sheet 72, the end 7 5 2 extends toward the inside of the radiating metal sheet 72, and the extending directions of the slit 75 and the slit 74 are opposite to each other. in

Page 14 1241742 V. Description of the invention (7) In the seventh embodiment, the radiating metal sheet 72 is made by bending a single metal sheet. Fig. 8 is a schematic diagram of another embodiment of the antenna of the present invention when the notebook computer 85 is used. The antenna of the present invention considers a telescopic structure. When the television signal receiving antenna 82 wants to receive a signal, the television signal receiving antenna 82 projects upward from between the LCD screen 84 and the supporting metal back plate 83 of the LCD screen.

Fig. 9 is a schematic diagram of another embodiment of the antenna of the present invention when the notebook computer 95 is not in use. When the TV signal receiving antenna 9 2 is not in use, it can be retracted from the upper edge of the supporting metal back plate 9 3 of the LCD screen and retracted between the LCD screen 9 4 and the supporting metal back plate 9 3 of the LCD screen. The notebook computer 9 5 does not see the TV signal receiving antenna 92. The embodiments described in the above description are only for explaining the principle of the present invention and its effects, but not for limiting the present invention. Therefore, those skilled in the art can modify and change the above embodiments without departing from the spirit of the present invention. The scope of power of the present invention should be listed in the scope of patent application described later.

Page 15 1241742 Brief Description of Drawings Figure 1 is a structural diagram of an embodiment of the antenna of the present invention. FIG. 2 is an experimental measurement result of return loss of an embodiment of the antenna of the present invention. Fig. 3 is a radiation field diagram of an embodiment of the antenna of the present invention. FIG. 4 is a gain diagram of an embodiment of the antenna of the present invention. FIG. 5 is a structural diagram of another embodiment of a radiating metal sheet of an antenna of the present invention. FIG. 6 is a structural diagram of another embodiment of a radiating metal sheet of an antenna of the present invention. FIG. 7 is a structural diagram of another embodiment of a radiating metal sheet of an antenna of the present invention. Fig. 8 is a schematic view showing another embodiment of the antenna of the present invention when the notebook computer is used. Figure 9 is a schematic diagram of another embodiment of the antenna of the present invention when the notebook computer is not in use. Description of component symbols: 1: An embodiment of the antenna of the present invention 10: a ground plane or a supporting metal back plate of a liquid crystal screen (LCD) of a notebook computer or a supporting metal back plate of a liquid crystal screen of a mobile television device 1 0 1: grounding point 1 0 2: One edge of the ground plane 1 2: Flat radiating metal sheet 1 2 1: Feed point 1 3: Slot 131: Starting end of the slit 1 3 2: End of the slit 1 4: Slit

Page 161241742 Brief description of the drawings 1 4 1: The beginning of the slit 1 4 2: The end of the slit 1 5: The slit 1 5 1: The beginning of the slit 1 5 2: The end of the slit 1 6: Feeding coaxial transmission line 1 6 1: Feeding the central conductor of the coaxial transmission line 1 6 2: Feeding the outer ground conductor of the coaxial transmission line 2 1: Operation mode of the antenna

5: Other embodiments of the radiating metal sheet of the antenna of the present invention 52: Planar radiating metal sheet 5 2 1: Feed point 5 3: Slot 531: Starting end of the slit 532: End of the slit 5 4: Slot

541: the beginning of the slit 542: the end of the slit 5 5: the slit 551: the beginning of the slit 552: the end of the slit 5 6: the slit

Page 171241742 Brief description of the drawing 561: The beginning of the slit 562: The end of the slit 6: Other embodiments of the radiation metal sheet of the antenna of the present invention 62: Planar radiation metal sheet 6 2 1: Feed point 6 2 2 : Microwave substrate 6 3: Slit 631: Start of slit 632: End of slit

6 4: Slit 641: The beginning of the slit 642: The end of the slit 7: Other embodiments of the radiation metal sheet of the antenna of the present invention 7 2: Radiation metal sheet 7 2 1: Feed point 7 2 2: Radiation metal Bend of the sheet 7 3: slit

731: The beginning of the slit 732: The end of the slit 7 4: The slit 741: The beginning of the slit 742: The end of the slit Ι · ϋ1Ι Page 18 1241742 Simple explanation of the drawing 7 5: Slot 751: Narrow Starting end of the slit 752: End of the slit 8: Other embodiments of the antenna of the present invention when used in a notebook computer 8 2: TV signal receiving antenna 8 3: Supporting metal back plate for the LCD screen 8 4: LCD screen 8 5 : Laptop

9: Other embodiments of the antenna of the present invention are shown when the notebook computer is not in use. Figure 9 2: TV signal receiving antenna 9 3: Supporting metal back plate for LCD screen 9 4: LCD screen 9 5: Notebook computer

Page 19

Claims (1)

1241742 VI. Scope of patent application 1. A wideband digital television receiving antenna, comprising: a ground plane, which is approximately rectangular in shape, the ground mask has a ground point; a flat radiating metal sheet is located on one edge of the ground plane Above, and extends in the opposite direction to the ground plane, and the planar radiating metal sheet has a feed point and a plurality of slits; and a feed coaxial transmission line for transmitting signals, including: a center wire connected to the The feed point of the planar radiating metal sheet; and an outer ground conductor connected to the ground point of the ground plane. 2. If the digital television receiving antenna of the first patent application range, wherein the plurality of slits each have a starting end and an end, the starting end is located on an edge of the radiating metal sheet, and the end is facing the radiation The inside of the metal sheet extends, and the plurality of slits are parallel to each other, and the extending directions of two adjacent slits are opposite to each other. 3. For example, the digital television receiving antenna of the scope of patent application, wherein the shape of the planar radiating metal sheet is approximately a rectangle with two truncated angles, and both of the truncated angles are directed toward the ground plane. 4. If the digital television receiving antenna of item 1 of the patent application scope, the shape of the flat radiating metal sheet is approximately a triangle. 5. The digital television receiving antenna according to item 1 of the scope of patent application, wherein the shape of the planar radiating metal sheet is substantially a trapezoid. Lu 6. The digital television receiving antenna according to item 1 of the patent application scope, wherein the flat radiating metal sheet is made by punching or cutting a single metal sheet. Page 20 1241742 6. Scope of patent application 7. The digital television receiving antenna of item 1 of the patent application scope, wherein the flat radiating metal sheet is formed on a microwave substrate by printing or etching technology. 8. —A wideband digital television receiving antenna comprising: a ground plane having a substantially rectangular shape, the ground mask having a ground point; a radiating metal sheet located above an edge of the ground plane and facing the ground The ground extends in the opposite direction and has a bend so that the radiating metal sheet forms an inverted L shape. At the same time, the radiating metal sheet has a feed point and a plurality of slits; and a coaxial transmission line is fed for transmission. The signal includes: a center wire connected to the feed point of the radiating metal sheet; and an outer ground conductor connected to the ground point of the ground plane. 9. The digital television receiving antenna according to item 8 of the patent application, wherein each of the plurality of slits has a starting end and an end, the starting end is located on an edge of the radiating metal sheet, and the end is facing the radiating metal sheet. It extends inside, and the plurality of slits are parallel to each other, and the extending directions of two adjacent slits are opposite to each other. 10. The digital television receiving antenna according to item 8 of the patent application, wherein the radiating metal sheet is made by bending a single metal sheet. Page 21