Electrical audio signal processing systems and devices – One-way audio signal program distribution
Patent
1997-07-16
2000-01-18
Chang, Vivian
Electrical audio signal processing systems and devices
One-way audio signal program distribution
H04B 300
Patent
active
060163518
ABSTRACT:
An ultrasonic beam (19) is used as a virtual array for an acoustic directional transmitter (11,21,31,41,51, and 61). The acoustic useful signal is modulated upon the ultrasonic beam as carrier via amplitude modulation, for example. The absorption of the ultrasonic power produces thermal expansion of the air and thus acoustic monopole radiation. At the same time, radiation pressure is released, resulting in dipole radiation. The superimposition of monopole and dipole produces a marked directivity characteristic. Since the ultrasonic sound possesses the same propagation velocity as the useful sound, the monopole and dipole radiation takes place within the virtual array correctly in terms of transit time, resulting in radiation that is directed extremely in the propagation direction. The effective array length can be adjusted over a wide range using the absorption coefficient that is a function of the carrier-frequency and, in extreme cases, a very punctual acoustic radiation can be realized at a wide distance. These types of directional transmitters are suitable as anti-sound generators and for directional signal and sound transmission. The ultrasonic carriers can be realized via piezoelectric (12) or pneumatic ultrasonic transmitters (22,32,42,52, and 62).
REFERENCES:
patent: 4265122 (1981-05-01), Cook et al.
patent: 4418404 (1983-11-01), Gordon et al.
patent: 4432079 (1984-02-01), Mackelburg et al.
patent: 5539705 (1996-07-01), Akerman et al.
Bschorr Oskar
Raida Hans-Joachim
American Technology Corporation
Chang Vivian
LandOfFree
Directed radiator with modulated ultrasonic sound does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Directed radiator with modulated ultrasonic sound, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Directed radiator with modulated ultrasonic sound will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-567979