Termination for RF circuit which senses changes in power and which is not temperature sensitive
US6147481A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1997 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Jun 3, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R21/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit for determining power changes in an RF circuit includes first and second temperature sensitive resistors connected in parallel with an RF input terminal so as to have a common junction therewith. The first resistor has a positive temperature coefficient of resistance and the second resistor has a negative temperature coefficient of resistance. A DC input terminal is connected to one of the temperature sensitive resistors and an output terminal is connected to the common junction of the two temperature sensitive resistors. Third and fourth temperature sensitive resistors have a common junction. The third resistor has a positive temperature coefficient of resistance and the fourth resistor has a negative temperature coefficient of resistance. The DC input terminal is also connected to one of the third and fourth temperature sensitive resistors, and an output terminal is connected to the common junction of the third and fourth temperature sensitive resistors. To improve the linearity of the circuit at high powers, each of the individual temperature sensitive resistors can be replaced with a pair of temperature sensitive resistors, one having a positive temperature coefficien…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.