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. 12, 2013
Filed:
Dec. 12, 2011
John P. Myers, Fremont, CA (US);
Petrus M. Stroet, Santa Cruz, CA (US);
John P. Myers, Fremont, CA (US);
Petrus M. Stroet, Santa Cruz, CA (US);
Linear Technology Corporation, Milpitas, CA (US);
Abstract
A mixer in an RF demodulator includes a transconductance amplifier that converts an RF input voltage (Vin), applied to the base of a first bipolar transistor, to a first output current. The first output current contains third order intermodulation (IM3) products. An IM3 canceller is connected in parallel with the transconductance amplifier. The base of a second bipolar transistor in the IM3 canceller is coupled to the DC component of Vin, and the AC component of Vin is coupled to the emitter of the second bipolar transistor, such that the currents though the first bipolar transistor and the currents through the second bipolar transistor change oppositely. The collectors of the transistors are coupled together. The values of components in the IM3 canceller are set so that the current generated by the IM3 canceller substantially cancels IM3 distortion in the first current or other current generated in a demodulator of Vin.