The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 15, 1999
Filed:
Dec. 19, 1996
Naoki Miyano, Osaka, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A broad-band amplifier circuit is furnished with a plurality of amplifiers with a coupling capacitor being interposed between every two adjacent amplifiers. Each coupling capacitor has a capacity large enough to prevent adverse effect of external noise. Accordingly, not only the passing of a signal having a low frequency is allowed, but also an element operable in a high frequency, such as a Schottky transistor, can be provided in each amplifier as a transistor. At least the transistor of the amplifier in the last stage is connected to a diode, so that the charges accumulated between its collector and base while the amplifier stays on are fed back and eliminated. Accordingly, the broad-band amplifier circuit can carry out a flat amplifying operation over a wide range from low to high frequency bands, and therefore, can be used for all the ASK method, IrDA1.0 method, and IrDA1.1 method. Consequently, not only the manufacturing cost, but also the size of the broad-band amplifier circuit can be reduced.