Electrical generator or motor structure – Non-dynamoelectric – Piezoelectric elements and devices
Patent
1982-01-07
1983-06-28
Budd, Mark O.
Electrical generator or motor structure
Non-dynamoelectric
Piezoelectric elements and devices
333154, 333193, H01L 4108
Patent
active
043908071
ABSTRACT:
In a preferred embodiment, a surface acoustic wave device comprises a piezoelectric substrate, a first electrode formed on the substrate and acting to convert an electrical signal into a surface acoustic wave, and second and third electrodes formed on the substrate and acting to convert the surface acoustic wave into an electrical signal. The second and third electrodes are disposed at different distances from the first electrode and connected electrically with each other. Electrode fingers of the second electrode are arranged in a relationship of the opposite polarity with respect to those of the third electrode so as to cause peaks in the constant frequency interval multi-peak frequency characteristics of the device acting as a filter to take place at frequencies which are (integer+1/2) times the constant frequency interval .DELTA.f. In another preferred embodiment, a plurality of surface acoustic wave device units are formed on a common piezoelectric substrate. Respective units include a set of first, second and third electrodes and operate at different frequency bands which partly overlap. The distance between the first electrode and the second electrode or the third electrode is determined in the respective units such that the delay time due to the propagation of the surface acoustic wave between the input and output electrodes is equal in the respective units and the output voltage of the output electrode is in phase in the respective units, thereby providing accurate peak frequencies over the whole frequency band at which the surface acoustic wave device operates.
REFERENCES:
patent: 3582540 (1971-06-01), Adler et al.
patent: 3596211 (1971-02-01), Dias
patent: 3810257 (1974-05-01), Jones et al.
patent: 3846723 (1974-11-01), Writer et al.
patent: 3855548 (1974-12-01), Nanoi et al.
patent: 3991330 (1976-11-01), Isaacs et al.
patent: 4060833 (1977-11-01), Onyshkevych
patent: 4178571 (1979-12-01), Mitchell
patent: 4203082 (1980-05-01), Tsukamoto et al.
Hazama Katashi
Kishimoto Kiyoharu
Yuhara Akitsuna
Budd Mark O.
Hitachi , Ltd.
LandOfFree
Surface acoustic wave device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Surface acoustic wave device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Surface acoustic wave device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-935694