Precise delay alignment between amplitude and phase/frequency modulation paths in a digital polar transmitter
US7817747B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 2007 |
| Grant date | Oct 19, 2010 |
| Priority date | — |
| Expiry date | Jul 9, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/02
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A novel apparatus for and method of delay alignment between amplitude and phase/frequency modulation paths in a digital polar transmitter. The invention provides a fully digital delay alignment mechanism where better than nanosecond alignment is achieved by accounting for processing delays in the digital circuit modules of the transmitter and by the use of programmable delay elements spread across several clock domains. Tapped delay lines compensate for propagation and settling delays in analog elements such as the DCO, dividers, quad switch, buffers, level shifters and digital pre-power amplifier (DPA). A signal correlative mechanism is provided whereby data from the amplitude and phase/frequency modulation paths to be matched is first interpolated and then cross-correlated to achieve accuracy better than the clock domain of comparison. Within the ADPLL portion of the transmitter, precise alignment of reference and direct point injection points in the ADPLL is provded using multiple clock domains, tapped delay lines and clock adjustment circuits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.