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:
Apr. 22, 2003
Filed:
Apr. 06, 2001
Alan R. Northam, Fairview, TX (US);
RF Monolithics, Inc., Dallas, TX (US);
Abstract
There is disclosed a SAW resonator-based oscillator circuit having low phase noise that is tunable across a comparatively wide frequency range. The oscillator circuit comprises: 1) a tuning element coupled to the input port and having a variable capacitance responsive to the frequency tuning signal; 2) a first inductor coupled in series with the tuning element; 3) a SAW resonator coupled in series with first inductor; 4) a second inductor coupled in parallel with the SAW resonator; 5) a negative resistance generating circuit coupled to the SAW resonator. Across the tunable operating frequency range of the oscillator circuit, the reactance looking into the input port is maintained at approximately zero and the resistance looking into the input port remains negative.