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:
Jan. 27, 1987
Filed:
Jan. 21, 1986
Helge O Granberg, Phoenix, AZ (US);
Samuel L Coffman, Scottsdale, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
An improved high frequency high power transistor assembly capable of delivering 600 watts or more at 100 MHz and higher without the need for water cooling is described. Four transistor die individually mounted on separate BeO ceramic isolators are installed in a recessed cavity in a copper base. The BeO isolators have metallized top surfaces which connect to the backside output contacts of the transistor die and extend toward the centerline of the cavity. They connect to a longitudally arranged input-output assembly centrally located over the center line of the cavity. The input-output assembly has a wrap-around electrode structure which brings the transistor output connections to the upper surface of the assembly for easy bonding to the output leads. The input to the individual die is via individual ballast resistors mounted on the input-output assembly, one per transistor, to provide transistor-to-transistor matching for more uniform current distribution.