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. 04, 2003
Filed:
Sep. 20, 1999
Paul Francis Alexander, Potomac, MD (US);
David John, Buckinghamshire, GB;
International Mobile Satellite Organization, London, GB;
Abstract
Digital audio recording equipment is used to record modulated signals, such as the RF test signals generated by test modems. If the modulated signals are outside the audio frequency range, they are down-converted into the audio frequency range using a mixer, local oscillator and a filter. The digitally converted data are recorded onto a suitable medium, such as a DAT, CD or a computer memory. The data is then disseminated for reproduction by a suitable digital audio player. The reproduced audio signal may be up-converted to the desired radio frequency using a mixer, local oscillator and a filter. The reproduced signal may be used to test demodulators, codecs or transceivers. The signals output by the transceiver and the reproduced signal may be recorded on different channels of the digital audio recording equipment. The recording equipment may be used to capture RF signals for later analysis. The player may be used for reproducing modulated signals for broadcast.