The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 14, 2007
Filed:
Apr. 15, 2005
Robert J. Blacka, Pennsauken, NJ (US);
Nelson Roldan, Boca Raton, FL (US);
Robert J. Blacka, Pennsauken, NJ (US);
Nelson Roldan, Boca Raton, FL (US);
Smiths Interconnect Microwave Components, Inc., Stuart, FL (US);
Abstract
A preferred embodiment of the present invention comprises at least first and second thermistors, arranged into a classical Tee, Pi, or Bridged Tee attenuator design, a heating element, a temperature sensor, and a control circuit. The thermistors have different temperature coefficients of resistance and are in close proximity to the heating element and the temperature sensor. The control circuit receives a voltage signal from the temperature sensor, compares that signal with a voltage signal specifying a desired temperature, and applies electrical energy to the heating element until receiving a signal from the temperature sensor that the temperature of the thermistors matches the desired temperature. As a result, the attenuation of the attenuator can be changed at a controlled rate by varying the temperature of the thermistors, while the impedance of the attenuator remains within acceptable levels.