Mobile communication apparatus
US7366489B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 23, 2003 |
| Grant date | Apr 29, 2008 |
| Priority date | — |
| Expiry date | Feb 15, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D2200/0047
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.