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. 04, 2009
Filed:
Dec. 15, 2005
Applicants:
Kevin S. Randall, Ambler, PA (US);
James J. Edelen, Iii, Jamison, PA (US);
Inventors:
Kevin S. Randall, Ambler, PA (US);
James J. Edelen, III, Jamison, PA (US);
Assignee:
Siemens Medical Solutions USA, Inc., Malvern, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03F 3/45 (2006.01);
U.S. Cl.
CPC ...
Abstract
A preamplifier has a variable input impedance. The input impedance is tailored with the signal level to maintain a more optimal performance. The input impedance is varied by at least two amplifiers connected in parallel. Each amplifier has a different input impedance. By controlling the bias currents to the amplifiers, the contribution to the input impedance of the parallel amplifiers is controlled. Gradual variation in input impedance may be obtained by gradual variation in relative contribution by the different amplifiers.