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:
Dec. 21, 1982
Filed:
Mar. 02, 1981
AEL Microtel, Ltd., Burnaby, CA;
Abstract
The baseband input to a frequency modulation radio transmitter is switchably connectable to a square wave generator, the amplitude of the square wave output being adjusted to provide a predetermined deviation of the FM radio transmitter. The output frequency of a pilot oscillator is also applied to the baseband input and is subjected to amplitude modulation because of non-linearities which exist in the system and which adversely affect the signal during transmission through the system. At the receiving end of the radio system, the receiver output contains a signal comprising the pilot frequency and a superimposed amplitude modulated signal, and this signal is applied to a product detector. The output of the product detector is a pulsating DC signal comprising a basic DC component, which is representative of the amplitude of the pilot frequency, and an AC component, which is representative of the system non-linearity. The pulsating DC signal is applied to one terminal of a capacitor. The AC component appears at the other terminal and is rectified and integrated to obtain a DC signal, the amplitude of which is proportional to the slope component in the system non-linearity. This DC signal is measured by a direct current meter.