Telecommunications – Receiver or analog modulated signal frequency converter – Noise or interference elimination
Patent
1997-09-25
2000-10-17
Trost, William G.
Telecommunications
Receiver or analog modulated signal frequency converter
Noise or interference elimination
455501, H04Q 732
Patent
active
061344281
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to communication apparatuses such as receivers and transmitters. The present invention more specifically relates to a technology for effectively reducing an effect of high-frequency noise generated by an integrated circuit (hereinafter called IC) in a communication apparatus, on an antenna body.
BACKGROUND ART
As a portable transmitter or receiver, a watch with an FM radio and a watch-shaped individual-selective-calling receiver have been known. In such a watch-type apparatus, an electrically conductive plate member or film is put in a watchband for mounting an apparatus body at a wrist. Therefore, when the watchband is mounted at the wrist, a loop antenna is formed by the plate member or film.
In such a communication apparatus, as typically shown in FIG. 9(b), the apparatus body includes a circuit board 73 on which a high-frequency analog IC 93B for transmission or receiving and a signal-processing digital IC 94B which is driven by a driving signal having a frequency as high as several MHz are mounted. These ICs (collectively indicated by A.cndot.B-IC in the figure) are wire-bonded on the rear surface section 732 of the circuit board 73 at the rear surface side (side where the entire or most part of a loop antenna 4 is disposed) of the circuit board 73. At the front surface side (side where a liquid crystal display panel 6 is disposed) of the circuit board 73, a display digital IC 95B (indicated by C-IC in the figure) which is driven by a several-tens-of-kHz driving signal is mounted on the front surface section 721 of a circuit board 72 by wire bonding.
Through various examinations into the effect of high-frequency noise in a wrist-mount-type communication apparatus, the inventor of this application found that sensitivity is low when the high-frequency analog IC 93B or the signal-processing digital IC 94B is wire-bonded to the rear surface section 732 of the circuit board 73. In other words, irrespective of high-frequency noise generated from the active surface (meaning a surface on which leads are exposed, a wiring surface, and a device surface) 930B or 940B of the high-frequency analog IC 93B or the signal-processing digital IC 94B, when the high-frequency analog IC 93B or the signal-processing digital IC 94B is disposed conventionally such that the active surface 930B or 940B faces the loop antenna 4, it is because the loop antenna 4 is susceptible to the effect of the high-frequency noise.
In consideration of the foregoing problem, it is an object of the present invention to provide a highly sensitive communication apparatus which reduces the effect of high-frequency noise generated from the active surface of an IC by appropriately disposing the IC that serves as a noise source.
DISCLOSURE OF INVENTION
To solve the foregoing problem, the object of the present invention is achieved through the provision of a communication apparatus including a board on which an integrated circuit generating high-frequency noise is mounted; and an antenna body the entire or most of which is disposed on one board-surface side of the board, wherein the integrated circuit is mounted on the board such that the active surface thereof directs at the direction opposite the direction where the entire or most of the antenna body is disposed against the board.
In a communication apparatus according to the present invention, since the active surface of an integrated circuit generating high-frequency noise directs at the direction opposite the direction where the entire or most of the antenna body is disposed, even if the integrated circuit emits high-frequency noise from its active surface, the high-frequency noise unlikely reaches the antenna body. Therefore, the sensitivity of the communication apparatus can be increased.
To make such a communication apparatus to be of a wrist-mount-type, the communication apparatus is, for example, provided with an apparatus body in which a side on which a display screen is formed is set to a front surface side and a watchband extending from
REFERENCES:
patent: 5134724 (1992-07-01), Gehring et al.
patent: 5159713 (1992-10-01), Gaskill et al.
patent: 5179733 (1993-01-01), Matsui
patent: 5532705 (1996-07-01), Hama
patent: 5564096 (1996-10-01), Hama et al.
patent: 5589840 (1996-12-01), Fujisawa
patent: 5737272 (1998-04-01), Uchiyama et al.
Gelin Jean
Seiko Epson Corporation
Trost William G.
LandOfFree
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