Voltage controlled attenuator with no intermodulation distortion

An attenuator comprising:

• a substrate of an insulating material having a first surface;
• spaced first and second heater contact areas on the substrate surface;
• a layer of heater resistor material on the substrate extending between and contacting the first and second heater contact areas;
• a first temperature variable resistor layer on the substrate extending at least across a portion of the heater resistor material;
• a second temperature variable resistor layer on the substrate extending at least across a portion of the heater resistor material;
• an electrical connection between the first and second temperature variable resistor layers that forms a circuit in which attenuation changes with changes in the temperature of the first and second temperature variable resistance layer;
• spaced first and second sensor contact areas on the substrate;
• and
• a temperature sensor resistor layer on the substrate contacting the first and second sensor contact areas and positioned such that the temperature sensor resistor layer can detect the temperature of the first and second temperature variable resistor layers;
• wherein the attenuation of the attenuator can be varied by applying electrical energy to the heater resistor material.

A method for forming an attenuator comprising the steps of:

• forming spaced first and second heater contact areas on an insulating substrate;
• forming a layer of heater resistor material on the substrate extending between and contacting the first and second heater contact areas;
• forming a first temperature variable resistor layer on the substrate extending at least across a portion of the heater resistor material;
• forming a second temperature variable resistor layer on the substrate extending at least across a portion of the heater resistor material;
• forming an electrical connection between the first and second temperature variable resistor layers that forms a circuit in which attenuation changes with changes in the temperature of the first and second temperature variable resistance layers;
• forming spaced first and second sensor contact areas on the substrate;
• and
• forming a temperature sensor resistor layer on the substrate contacting the first and second sensor contact areas and positioned such that the temperature sensor resistor layer can detect the temperature of the first and second temperature variable resistor layers;
• wherein the attenuation of the attenuator can be varied by applying electrical energy to the heater resistor material.