EP0600705A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Surface acoustic wave filter and mobile communication system using same
Assignee: Japan Radio Co Ltd
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Filing: 1993-11-30
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Granted: —
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Expires: 2013-11-30
Abstract
Abstract A composite surface acoustic wave filter 701 includes an interdigitated interdigital surface acoustic wave filter 710 having input and output terminals A, B. Two one-port surface acoustic wave resonators 71a, 71b are electrically connected in series to the interdigitated interdigital surface acoustic wave filter 710 respectively at the input and output terminals A, B, the one-port surface acoustic wave resonators 71a, 71b having antiresonant frequencies in a stop band that is close to and higher than the passband of the interdigitated interdigital surface acoustic wave filter 710. Two other one-port surface acoustic wave resonators 72a, 72b are electrically connected parallel to the interdigitated interdigital surface acoustic wave filter 710, the one-port surface acoustic wave resonators 72a, 72b having resonant frequencies in a stop band that is close to and lower than the passband of the interdigitated interdigital surface acoustic wave filter 710.
Inventors
- 👤 Hiromi C/O Japan Radio Co. Ltd. Yatsuda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 11:23
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/64; H03H9/6423; H03H9/6433; H03H9/6483; H03H9/02; H03H9/125; H03H9/145; H03H9/14544; H03H9/1455; H03H9/6436; H03H9/644; H03H9/6456; H03H9/6469; H03H9/14517; H03H9/14526
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
45 words
A composite surface acoustic wave filter comprising: a surface acoustic wave filter having input and output terminals; and at least one surface acoustic wave resonator electrically connected in series to at least one of the input and output terminals of said surface acoustic wave filter.
Claim 2
Dependent Claim
39 words
A composite surface acoustic wave filter according to claim 1, wherein said surface acoustic wave resonator has an antiresonant frequency in a stop band which is close to and higher than a passband of said surface acoustic wave filter.
Claim 3
Dependent Claim
56 words
A composite surface acoustic wave filter according to claim 1, wherein said surface acoustic wave filter comprises an interdigitated interdigital surface acoustic wave filter comprising a plurality of input transducers electrically connected in parallel to each other, and a plurality of output transducers disposed between said input transducers and electrically connected in parallel to each other.
Claim 4
Dependent Claim
24 words
A composite surface acoustic wave filter according to claim 1, wherein said surface acoustic wave filter comprises a two-port surface acoustic wave resonator filter.
Claim 5
Dependent Claim
23 words
A composite surface acoustic wave filter according to claim 1, wherein said surface acoustic wave resonator comprises a one-port surface acoustic wave resonator.
Claim 6
Dependent Claim
30 words
A composite surface acoustic wave filter according to claim 1, further comprising a substrate, said surface acoustic wave filter and said surface acoustic wave resonator being mounted on said substrate.
Claim 7
Dependent Claim
44 words
A composite surface acoustic wave filter comprising: a surface acoustic wave filter having input and output terminals; and at least one surface acoustic wave resonator electrically connected parallel to at least one of the input and output terminals of said surface acoustic wave filter.
Claim 8
Dependent Claim
39 words
A composite surface acoustic wave filter according to claim 7, wherein said surface acoustic wave resonator has a resonant frequency in a stop band which is close to and lower than a passband of said surface acoustic wave filter.
Claim 9
Dependent Claim
54 words
A composite surface acoustic wave filter according to claim 7, wherein said surface acoustic wave filter comprises an interdigitated interdigital surface acoustic wave filter comprising a plurality of input transducers electrically connected parallel to each other, and a plurality of output transducers disposed between said input transducers and electrically connected parallel to each other.
Claim 10
Dependent Claim
24 words
A composite surface acoustic wave filter according to claim 7, wherein said surface acoustic wave filter comprises a two-port surface acoustic wave resonator filter.
Claim 11
Dependent Claim
23 words
A composite surface acoustic wave filter according to claim 7, wherein said surface acoustic wave resonator comprises a one-port surface acoustic wave resonator.
Claim 12
Dependent Claim
30 words
A composite surface acoustic wave filter according to claim 7, further comprising a substrate, said surface acoustic wave filter and said surface acoustic wave resonator being mounted on said substrate.
Claim 13
Dependent Claim
63 words
A composite surface acoustic wave filter comprising: a surface acoustic wave filter having input and output terminals; at least one first surface acoustic wave resonator electrically connected parallel to at least one of the input and output terminals of said surface acoustic wave filter; and at least one second surface acoustic wave resonator electrically connected in series to said surface acoustic wave filter.
Claim 14
Dependent Claim
70 words
A composite surface acoustic wave filter according to claim 13, wherein said first surface acoustic wave resonator has a resonant frequency in a stop band which is close to and lower than a passband of said surface acoustic wave filter, and said second surface acoustic wave resonator has an antiresonant frequency in a stop band which is close to and higher than the passband of said surface acoustic wave filter.
Claim 15
Dependent Claim
54 words
A composite surface acoustic wave filter according to claim 13, wherein said surface acoustic wave filter comprises an interdigitated interdigital surface acoustic wave filter comprising a plurality of input transducers electrically connected parallel to each other, and a plurality of output transducers disposed between said input transducers and electrically connected parallel to each other.
Claim 16
Dependent Claim
24 words
A composite surface acoustic wave filter according to claim 13, wherein said surface acoustic wave filter comprises a two-port surface acoustic wave resonator filter.
Claim 17
Dependent Claim
28 words
A composite surface acoustic wave filter according to claim 13, wherein each of said first and second surface acoustic wave resonators comprises a one-port surface acoustic wave resonator.
Claim 18
Dependent Claim
33 words
A composite surface acoustic wave filter according to claim 13, further comprising a substrate, said surface acoustic wave filter and said first and second surface acoustic wave resonators being mounted on said substrate.
Claim 19
Dependent Claim
38 words
A mobile communication system including filters in an antenna sharing unit and interstage filters, each of said filters and said interstage filters comprising any one of the composite acoustic surface wave filters according to claims 7 through 18.
References Cited (Backward Citations)
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