Apparatus and method for generating a transition between the on and off states of a radio frequency transmitter
US5621763A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1995 |
| Grant date | Apr 15, 1997 |
| Priority date | — |
| Expiry date | May 15, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G3/3047
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An apparatus and method generates a shaped transition between the minimum and maximum output power levels of a transmitter (500). When the transmitter is turned on a stepped transition (415) is generated at the beginning (3) of the transition region (409) followed by a shaped transition (417) to the end (6) of the transition region (409). When the transmitter (500) is turned off a shaped transition region (417') is generated at the beginning (162) of the transition region (411) followed by a stepped transition (415') at the end (3) of the transition region (411). The stepped transition (415 or 415') is generated by adjusting a voltage controlled attenuator (545) and the bias of a power amplifier (545) in the transmitter (500). The shaped transition (417 or 417') is generated by processing transmitted information through finite impulse response filters (507 or 509) before or after the time slot permitted for transmitting information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.