True root-mean-square detection with a sub-threshold transistor bridge circuit
US8060040B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 18, 2008 |
| Grant date | Nov 15, 2011 |
| Priority date | — |
| Expiry date | May 13, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R21/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sub-threshold transistor bridge circuit for use in detecting the signal level of an input radio-frequency signal is disclosed. In an exemplary embodiment each branch of the sub-threshold transistor bridge circuit comprises a transistor configured to operate in the sub-threshold region over a predetermined range of input signal levels. An input radio-frequency signal applied to a first pair of opposing corners of the bridge circuit yields a bridge output signal at the remaining pair of opposing corners that has a low-frequency component substantially proportional to the squared-amplitude of the envelope of the input radio-frequency signal. Also disclosed are various detector circuits including a sub-threshold transistor bridge circuit, as well as methods for detecting a signal level for an radio-frequency signal using a sub-threshold transistor bridge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.