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. 11, 1980
Filed:
Jul. 06, 1978
Applicant:
Inventor:
Ian A Vance, Newport, GB;
Assignee:
International Standard Electric Corporation, New York, NY (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H04L / ;
U.S. Cl.
CPC ...
375 88 ; 178 661 ; 329104 ;
Abstract
A simple radio receiver for FSK signals as used in a paging system. RF signals from the aerial are mixed in two high gain mixers with local oscillator signals which are in quadrature and which are at the nominal center frequency of the input signal. The output from the mixers are low-pass filtered so as to extract the difference frequency. The low-pass filter bandwidth is equal to the sideband width of the RF signal. Baseband signals from the filters are now amplified in high gain limiting amplifier stages which deliver fully symmetrically limited outputs at logic level to a D-type flip-flop.