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:
Mar. 31, 1987
Filed:
Jan. 15, 1985
Georg Sebald, Munich, DE;
Alfred Nist, Grafrath, DE;
Siemens Aktiengesellschaft, Berlin and Munich, DE;
Abstract
A 1 bit/1 bit digital correlator includes a digital multiplier stage and an analog integrator stage, the analog integrator stage having a feedback loop for automatically adjusting a reference voltage for the integrator. The digital multiplier may be an exclusive OR gate which combines two incoming digital sequences and generates a digital output sequence which is divided into two paths in the integrator stage, one path being utilized for obtaining the reference voltage for the integrator and the other path forming a signal path for the integrator. The reference voltage path includes a switch operated by a refresh signal for selectively completing an RC network which is connected to the non-inverting input of an operational amplifier. The signal path includes a low-pass filter connected through a resistor to the inverting input of the operational amplifier, the operational amplifier having a capacitor connected across its output and its inverting input. A feedback loop for resetting the integrator stage is also connected between the output of the first operational amplifier and its inverting input and includes a second operational amplifier having an output selectively connectable through a further switch to the inverting input of the first operational amplifier, and having an inverting input to which a reference starting voltage is supplied and a non-inverting input connected to the output of the first operational amplifier.