JP4457850B2 - Substrate mounted thin antenna - Google Patents

Description

  The present invention relates to a board-mounted thin antenna mounted on a module board or the like on which a mini PCI or antenna oscillation circuit is mounted.

  Wireless LAN (IEEE 802.11a (including so-called hyper a) / b / g) using a board-mounted thin antenna mounted on a module board or the like on which a mini PCI or antenna oscillation circuit is mounted has begun to spread.

  This wireless LAN includes the 802.11b standard using 2.4 to 2.5 GHz and the 802.11a standard using 4.9 to 6.0 GHz. As antennas for the wireless LAN, these 2.4 GHz antennas are used. There has been a demand for a flat plate antenna capable of dual-band oscillation in a band and a 5 GHz band.

  Conventionally, as a flat antenna, as shown in Patent Document 1, a flat antenna in which a lead frame is punched to form a ground part and a radiating element part, or as shown in Patent Document 2, it is formed on both surfaces of an insulating substrate. There is an antenna device in which an inverted F antenna is formed by using a conductive film.

JP 2003-152429 A JP 2003-8325 A

  However, these antennas require a power supply cable and are attached to the peripheral frame of the display, and cannot be directly mounted on the module substrate.

  In addition, 802.11a using the 5 GHz band has been attracting attention recently because it has a higher communication speed and less influence of noise than 802.11b using the 2 GHz band. Since they are operated at different frequencies in Japan, etc., a broadband antenna is required to adapt to all these different frequencies.

  An object of the present invention is to provide a substrate-mounted thin antenna that can be mounted on a module substrate and can cover a wide band.

In order to achieve the above object, according to the first aspect of the present invention, in a board-mounted thin antenna mounted on a module board, a ground plane and an insulating plane are formed on the module board, and a ground contact is formed near the insulating plane of the ground plane. Then, a feeding point is formed on the insulating surface so as to face the ground contact, a reverse L-shaped transmission path is formed on the insulating surface from the feeding point to the ground surface, and a loop element that short-circuits the feeding point and the ground contact is formed. Forming first and second radiating elements extending in opposite directions from the feeding point on the insulating surface, the loop element and the first radiating element are opposed to each other, and the length of the first radiating element is The first radiating element is formed to have a length that is ¼ of the reception wavelength λ1, and the second radiating element has a length that is ¼ of the reception wavelength λ2 of the second radiating element. The length of the loop element is set to the reception wavelength λ Of a substrate mounting thin antenna formed in length.

According to a second aspect of the present invention, in the substrate-mounted thin antenna mounted on the module substrate, a ground surface and an insulating surface are formed on the module substrate, and a ground contact is formed near the insulating surface of the ground surface so as to face the ground contact. A feeding point is formed on the insulating surface, and first and second reverse L-shaped transmission lines are formed on the insulating surface from the feeding point to the ground planes on both sides, and the feeding point and the ground contact are short-circuited. A second loop element is formed, and first and second radiating elements extending in opposite directions from the feeding point are formed on the insulating surface, and the length of the first radiating element is set to the reception wavelength λ1 of the first radiating element. The length of the second radiating element is formed to be ¼ of the reception wavelength λ2 of the second radiating element, and the length of the first loop element is The second wavelength is formed to a length of the reception wavelength λ1. The length of the element is a substrate mounting thin antenna formed on the length of the reception wavelength .lambda.2.

According to a third aspect of the present invention, the ground surface, the loop element, and the radiating element formed on the module substrate are formed on the insulating plate by etching a conductive material or by printing a pattern. It is an antenna.

  A fourth aspect of the present invention is the substrate-mounted thin antenna according to any one of the first to third aspects, in which a high-frequency power source is connected to the feeding point and the ground contact from the back side of the module substrate.

  The present invention can realize an antenna that can be easily mounted on a module substrate and can oscillate in a wide band.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a plan view of a substrate-mounted thin antenna according to the present invention.

  In FIG. 1, reference numeral 10 denotes a module substrate on which a mini PCI or an antenna oscillation circuit is mounted. A ground surface 11 and an insulating surface 12 are formed on the module substrate 10.

  A ground contact 13 is formed at the center of the ground surface 11 near the insulating surface 12, and a feeding point 14 is formed on the insulating surface 12 so as to face the ground contact 13.

  A reverse L-shaped first transmission line 15 a is formed from the feeding point 14 to the ground surface 11, a first loop element 15 that short-circuits the feeding point 14 and the ground contact 13 is formed, and the first transmission is performed from the feeding point 14. An inverted L-shaped second transmission path 16a is formed symmetrically with the path 15a, and a second loop element 16 that short-circuits the feeding point 14 and the ground contact 13 is formed.

  A rising piece 17 is formed from a feeding point 14, which is a connecting portion between the first loop element 15 and the second loop element 16, and a first radiating element 18 and a second radiating element extending in opposite directions from the rising piece 17. An element 19 is formed.

  The feeding point 14 and the ground contact 13 are connected to a high frequency power source 20 on the back side of the module substrate 10. The high frequency power supply 20 may be fed with a microstrip line.

The length from the feeding point 14 to the tip of the first radiating element 18 is ¼ wavelength in the 2 GHz band, and the length from the feeding point 14 to the tip of the second radiating element 19 is in the 5 GHz band. The first loop element 15 formed to have a quarter wavelength and extending from the feeding point 14 to the ground contact 13 is formed with one wavelength in the 2 GHz band, and similarly the second loop element 16 is formed with one wavelength in the 5 GHz band. Is done.

  The ground surface 11, the first and second loop elements 15 and 16, and the first and second radiating elements 18 and 19 formed on the module substrate 10 may be formed by etching a plated copper foil or the module substrate 10. The antenna shape may be directly printed on the substrate. In addition to the copper foil, phosphor bronze, iron, and other various conductive materials may be used as the antenna material.

  FIG. 2 shows a plan view of another embodiment of the substrate-mounted thin antenna of the present invention.

  In the present embodiment, an inverted L-shaped second transmission line 16a is formed from the feeding point 14 to the ground plane 11, and the second loop element 16 that short-circuits the feeding point 14 and the ground contact 13 is formed. A rising piece 17 is formed at the tip of the loop element 16, and a first radiating element 18 and a second radiating element 19 extending in opposite directions from the rising piece 17 are formed.

  In the form of FIG. 2, unlike FIG. 1, only the second loop element 16 having the resonance frequency in the 5 GHz band is formed without forming the first loop element 15 having the resonance frequency in the 2 GHz band. The two-loop element 16 is arranged in parallel with the first radiating element 18 having a resonance frequency in the 2 GHz band, and the second radiating element 19 having the resonance frequency in the 5 GHz band is opposite to the feeding point 14 as a boundary. Thus, mutual interference is prevented.

  FIG. 3 shows antenna characteristics of the substrate-mounted thin antenna shown in FIG.

  As shown in FIG. 3, there are resonance frequencies in the 2 GHz band and the 5 Hz band. In the 2 GHz band, the return loss is −15 dB or less at 2.4 to 2.5 GHz, and the return loss is 4.9 to 6.0 GHz in the 5 GHz band. Wide band antenna characteristics of -25 dB or less.

It is a top view which shows one Embodiment of the board | substrate mounted thin antenna of this invention. It is a top view which shows other embodiment of the board | substrate mounted thin antenna of this invention. It is a figure which shows the antenna characteristic of the board | substrate mounted thin antenna in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Module board | substrate 11 Ground surface 12 Insulating surface 13 Ground contact 14 Feed point 15 1st loop element 15a 1st transmission line 16 2nd loop element 16a 2nd transmission line 18 1st radiation element 19 2nd radiation element 20 High frequency power supply

Claims (4)

In a board-mounted thin antenna mounted on a module board, a ground surface and an insulating surface are formed on the module substrate, a ground contact is formed near the insulating surface of the ground surface, and a feeding point is formed on the insulating surface so as to face the ground contact Then, an inverted L-shaped transmission line is formed on the insulating surface from the power supply point to the ground surface, and a loop element that short-circuits the power supply point and the ground contact is formed. First and second extending radiating elements are formed , the loop element and the first radiating element are made to face each other, and the length of the first radiating element is ¼ of the reception wavelength λ1 of the first radiating element. The length of the second radiating element is formed to be ¼ of the receiving wavelength λ2 of the second radiating element, and the length of the loop element is formed to be the length of the receiving wavelength λ1. substrate mounting thin, characterized in that the Antenna. In a board-mounted thin antenna mounted on a module board, a ground surface and an insulating surface are formed on the module substrate, a ground contact is formed near the insulating surface of the ground surface, and a feeding point is formed on the insulating surface so as to face the ground contact Then, reverse L-shaped first and second transmission lines are formed on the insulating surface from the feeding point to the ground planes on both sides, and first and second loop elements that short-circuit the feeding point and the ground contact are formed. First and second radiating elements extending in opposite directions from the feeding point are formed on the insulating surface, and the length of the first radiating element is ¼ of the reception wavelength λ1 of the first radiating element. The length of the second radiating element is formed to be ¼ of the receiving wavelength λ2 of the second radiating element, and the length of the first loop element is set to the length of the receiving wavelength λ1. Forming the length of the second loop element above Substrate mounting thin antenna, characterized in that formed in the length of the signal wavelength .lambda.2. The board-mounted thin antenna according to claim 1 or 2, wherein the ground surface, the loop element, and the radiating element formed on the module substrate are formed by etching a conductive material or printing a pattern on an insulating plate.   The board-mounted thin antenna according to any one of claims 1 to 3, wherein a high-frequency power source is connected to a feeding point and a ground contact from the back side of the module board.

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