Cascade low-pass filter to improve xDSL band attenuation for POTS splitter
US6853724B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 10, 2002 |
| Grant date | Feb 8, 2005 |
| Priority date | — |
| Expiry date | Jun 13, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/76
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Cascade low-pass filters are useful in attenuating the xDSL band in a POTS splitter. The design of the low-pass filter is a sixth-order filter having two stages. A first stage includes a fourth-order filter, preferably with a stop-band frequency of approximately 48 kHz. A second stage includes a second-order filter in cascade with the fourth-order filter. For this filter, the stop-band frequency is preferably approximately 29 kHz. The inductance value of the second stage is relatively small in comparison to the inductance values of the first stage. In this manner, improvements in xDSL band attenuation are facilitated with little or no eroding of the voice band performance such as insertion loss, pass-band attenuation and return loss.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.