Split band filter for cellular mobile radio
US4783843A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 1986 |
| Grant date | Nov 8, 1988 |
| Priority date | — |
| Expiry date | May 23, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W16/26
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A split band filtering scheme to reduce adjacent band interference in a communications network, such as a cellular mobile radio system, is disclosed. A repeater, interposed between a base or cell site and a mobile/portable radio, includes a down converter for converting a system operating frequency to a lower frequency signal. The lower frequency signal represents a communications band. The signal is presented to a split band filter having a narrow passband with steep skirts. The processed signal is coupled to an up converter where it is restored to the system operating frequency. In this way, the passband of the repeater is restricted to that of the desired communications band and adjacent band interference is reduced or eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.