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:
Apr. 12, 2005
Filed:
Dec. 04, 2003
Douglas D. Coolbaugh, Essex Junction, VT (US);
Stephen S. Furkay, South Burlington, VT (US);
Mohamed Youssef Hammad, Youngtown, AZ (US);
Jeffrey B. Johnson, Essex Junction, VT (US);
Douglas D. Coolbaugh, Essex Junction, VT (US);
Stephen S. Furkay, South Burlington, VT (US);
Mohamed Youssef Hammad, Youngtown, AZ (US);
Jeffrey B. Johnson, Essex Junction, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A varactor diode having a first electrode comprising a well region of a first conductivity type in a substrate, a second electrode comprising a first plurality of diffusion regions of a second conductivity type abutting isolation regions disposed in said well region, and a second plurality of diffusion regions of said first conductivity type extending laterally from portions of said first plurality of diffusion regions not adjacent said isolation regions and having a dopant concentration greater than that of said first plurality of diffusion regions. The varactor has a tunability of at least approximately 3.5 in a range of applied voltage between approximately 0V to 3V, an approximately linear change in capacitive value in a range of applied voltage between approximately 0V to 2V, and a Q of at least approximately 100 at a circuit operating frequency of approximately 2 GHz.