US 6,147,481 A · Termination for RF circuit which senses changes in power and which is not temperature sensitive

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 coefficient of resistance and the other having a negative temperature coefficient of resistance. In such circuit four output terminals are provided with each output terminal being connected to the junction between the temperature sensitive resistors of each pair.

Claims29

Dependent claims

A power detector for an RF circuit comprising:

an RF input;
first and second temperature sensitive resistors connected together with a common junction to which the RF input is connected, the first temperature resistor having a positive temperature coefficient of resistance and the second temperature sensitive resistor having a negative temperature coefficient of resistance;
an output terminal connected to the common junction of said first and second temperature sensitive resistors;
means for applying a DC voltage to one of the temperature sensitive resistors;
third and fourth temperature sensitive resistors connected together with a common junction, the third temperature sensitive resistor having a positive temperature coefficient of resistance and the fourth temperature sensitive resistor having a negative temperature coefficient of resistance;
a second output terminal connected to the common junction of the third and fourth temperature sensitive resistors;
and
the means for applying a DC voltage is also connected to one of the third and fourth temperature sensitive resistors.

5 more elements

An electronic device for detecting the power of an RF circuit comprising:

a substrate of an insulating material having a substantially flat surface and a plurality of edges;
first and second areas of a layer of a temperature sensitive resistance material on said substrate surface, the material of the first area having a positive temperature coefficient of resistance and the material of the second area having a negative temperature coefficient of resistance;
an area of a layer of conductive metal on said substrate surface connecting said first and second temperature sensitive resistance areas;
an area of a layer of a conductive metal on said substrate surface adjacent an edge of the substrate and forming an RF input terminal;
means on said substrate surface electrically connecting the RF input terminal to the conductive metal area connecting the first and second temperature sensitive resistance areas;
an area of a layer of a conductive metal on the substrate surface adjacent an edge of the substrate and forming a DC input terminal;
means on said substrate surface electrically connecting the DC input terminal area to one of the first and second temperature sensitive resistance areas;
an area of a layer of a conductive metal on said substrate surface adjacent an edge of the substrate and forming an output terminal;
and
means electrically connecting the output terminal area to the conductive metal area connecting the first and second temperature sensitive resistance areas.

7 more elements

Dependencies are inferred from the claim text.

Termination for RF circuit which senses changes in power and which is not temperature sensitive

Life of this patent

Termination for RF circuit which senses changes in power and which is not temperature sensitive

Life of this patent

Abstract

Claims29