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. 20, 1998
Filed:
Feb. 26, 1997
Makoto Shikata, Tokyo, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
A synthesized oscillation circuit that can relax a limitation of the maximum operational frequency. A mixer (MX), a bandpass filter (BPF), an amplitude limiting amplifier (LIM), a phase detector (PD), a low-pass filter (LPF), and a voltage-controlled oscillator (VCO) are serially connected between a signal input terminal (IN) and a signal output terminal (OUT). The signal output terminal (OUT) is connected the mixer (MX) and the phase detector (PD). The bandpass filter (BPF) has a filtering characteristic which blocks the sum frequency component of the frequency component of an input signal from the signal input terminal (IN) to the mixer (MX) and the frequency component of an output signal from the voltage-controlled oscillator (VCO) to the mixer (MX), but which passes the difference frequency component between them. The low-pass filter (LPF) has a filtering characteristic which blocks the sum frequency component of the frequency component of a signal from the voltage-controlled oscillator (VCO) to the phase detector (PD) and the frequency component of a signal from the voltage-controlled oscillator (VCO) to the phase detector (PD), but which passes the difference frequency signal between them.