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:
Jul. 15, 1986
Filed:
Aug. 27, 1984
Vladan Temer, Santa Rosa, CA (US);
Other;
Abstract
A bandpass filter is presented which is constructed so that bandwidth of the bandpass filter may be varied without varying gain from an input signal to an output signal when the input signal is at a center frequency. A crystal resonator is connected in series with a compensation resistance, and a variable resistance. Ignoring shunt capacitance, the crystal resonator may be modelled by a capacitance, an inductance and a loss resistance coupled in series. The compensation resistance is chosen so that the voltage drop across the compensation resistance is equal to the voltage drop across the loss resistance. A transformer having a primary coil, a secondary coil, and a 1:1 turn ratio between the two coils is included in the circuit. The primary coil is coupled in parallel with the compensation resistance. The output signal appears at an output of the secondary coil.