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:
Feb. 14, 1989
Filed:
May. 10, 1988
David K Donald, Mountain View, CA (US);
Shih-Yuan Wang, Palo Alto, CA (US);
Tirumala R Ranganath, Palo Alto, CA (US);
Steven A Newton, Belmont, CA (US);
William R Trutna, Atherton, CA (US);
David M Bloom, Menlo Park, CA (US);
Frank K David, Santa Rosa, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A parametric photodiode amplifier suitable for detecting light of frequency f and intensity P and having intersecting I:V curves for zero incident light and for incident light of intensity P. These photodiodes typically have an intrinsic density of carriers that is on the order of or less than the density of carriers produced by incident light of intensity P. When the photodiode is biased by an LO signal and is illuminated with modulated light of carrier frequency f, the photodiode output signal contains IF components at the difference between the frequencies of the modulation signal and the frequencies of on the order of the 23 lower harmonics of the LO signal.