High frequency variable gain amplifier device and wireless communications terminal
US6118989A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 1997 |
| Grant date | Sep 12, 2000 |
| Priority date | — |
| Expiry date | Nov 19, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/70
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
To obtain a more stable gain control range and to reduce power consumption with a smaller scale circuitry having simpler configuration for gain control, a high frequency variable gain amplifier includes multi stage transistor amplifiers, a change-over switch circuit for controlling supplying and interruption of a power supply voltage, and a field effect transistor switch circuit with grounded-gate connection inserted in a bypass path midway across an input terminal and an output terminal. The source of this field effect transistor switch is in direct current-connection to the drain of a field effect transistor of the final stage transistor amplifier circuit. When a power supply voltage is supplied to each of the transistor amplifiers via the change-over switch circuit, the field effect transistor switch is turned "off" and when the power supply voltage is interrupted, the field effect transistor switch is tuned "on".
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.