Compact phase shifter circuit using coupled lines
US6320481A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 11, 1999 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Jun 11, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01P1/18
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention provides a switched-line phase shifter (300) for creating a differential phase shift between switched transmission paths (302, 304). A switched-line phase shifter (300) incorporates Schiffman sections (306, 308) of lengths which are non-integer multiples of quarter-wavelength. The lengths of the Schiffman sections (306, 308) are chosen such that no isolation points, which result from frequencies at which the effective electrical length of one of the transmission paths (302, 304) is an integer multiple of .lambda./2, occur over the operating frequency range of the phase shifter (300). The present invention also provides a space-efficient implementation of a switched-line phase shifter (600) which utilizes switches (640, 642, 644) between Schiffman subsections (610, 630) to alternately combine and isolate the Schiffman subsections (610, 630) thereby alternately creating effective Schiffman sections of greater and lesser length respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.