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:
Oct. 03, 2000
Filed:
Jul. 23, 1998
Thomas Byunghak Cho, Alameda, CA (US);
Level One Communications, Inc., Sacramento, CA (US);
Abstract
A low noise amplifier circuit provides high gain and an input impedance matching a source output impedance by combining two amplifiers having different operational characteristics in parallel. The amplifier circuit includes a first amplifier having an input impedance matching a source and a gain less than a system requirement and a second amplifier having a gain meeting the system requirement and an input impedance substantially higher than the input impedance of the first amplifier, the second amplifier being connected in parallel to the first amplifier. The first amplifier includes an input and an output and the second amplifier includes an input and an output, the input to the first amplifier and the input to the second amplifier being connected to the source. A summer is provided for combining an output signal from the first amplifier with an output of the second amplifier. The input impedance of the first amplifier and the input impedance of the second amplifier provide an effective circuit impedance equal to an output impedance of the source. The first and the second amplifier include low noise RF amplifiers. Thus, the first and second amplifier provide an effective gain meeting the system requirement and an effective input impedance matching an output impedance of the source.