Active polyphase filter producing two difference outputs having phase difference of π/2 radians
US8217715B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 7, 2010 |
| Grant date | Jul 10, 2012 |
| Priority date | — |
| Expiry date | Feb 26, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2007/0192
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An active poly-phase filter has a converting section and a filtering section having two first input terminals, two second input terminals and four output terminals. The converting section has first, second, fourth and fifth transistors forming a translinear circuit and a third transistor forming a current mirror circuit with the second transistor. The converting section converts unbalanced high-frequency power into a difference input between a collector current of the third transistor and a collector current of the first transistor having phase difference of π radians. The filtering section receives one collector current at the first input terminals and receives another collector current at the second input terminals and outputs a first difference output between outputs of two output terminals and a second difference output between outputs of other two output terminals such that the difference outputs has a phase difference of π/2 radians.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.