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. 21, 1987
Filed:
Jun. 11, 1986
Roger K Loper, Norway, IA (US);
Richard A Freeman, Cedar Rapids, IA (US);
Rockwell International Corporation, El Segundo, CA (US);
Abstract
The bandwidth of frequency modulated signals is limited in a digital data transmission system by shaping the square digital waveform to form a trapezoidal shaped waveform having a positively-sloped ramp on the leading edge of the waveform and negatively-sloped ramp on the following edge of the waveform. Provisions are made to selectively determine the slope of the ramps and the amplitude of the waveform so that the system can be used with a wide range of data transmission speeds without resort to bandpass filter or component changes as were required in the prior art. Provision is also made for transmission of analog data in the same system by providing a feedback loop which causes the ramping to follow, and thus approximate, the analog waveform. The shaped data signal is fed to a frequency synthesizer which produces a frequency modulated sine wave whose frequency deviation is related to the magnitude of the digital or analog data signal.