US4598426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable intermediate bandwidth AM receiver
Assignee: Trio KK
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Filing: 1984-04-04
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Granted: 1986-07-01
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Expires: 2004-04-04
Abstract
Abstract There is provided an AM receiver in which the bandwidth of an intermediate frequency amplifier is continuously varied in accordance with the received field strength. This AM receiver includes a combining circuit for combining a first AM detection output A from a narrow band intermediate frequency amplifier and a second AM detection output B from a wide band intermediate frequency amplifier to produce an AM signal output of A(1-a M )+a M B (where, 0≦a M ≦1). By varying the coefficient a M , the bandwidth of the intermediate frequency amplifier can be equivalently continuously varied between the wide band and narrow band.
Inventors
- 👤 Kazuo Shiojima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:11
CPC Classifications
H; H03; H03G; H03G5/00; H03G5/16; H03G5/24; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/1638
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
106 words
An AM receiver comprising: a narrow band intermediate frequency amplifier; a first AM detector for detecting a signal from said narrow band amplifier to produce a first AM detection output signal A; a wide band intermediate frequency amplifier; a second AM detector for detecting a signal from said wide band amplifier to produce a second AM detection output signal B; and a circuit for combining said first and second AM detection output signals A and B at a coefficient a M to produce an AM detection output A(1-a M )+a M B, where, 0≦a M ≦1, the coefficient a M being variable in said combining circuit.
Claim 2
Dependent Claim
106 words
An AM receiver comprising: a narrow band intermediate frequency amplifier; a first AM detector for detecting a signal from said narrow band amplifier to produce a first AM detection output signal A; a wide band intermediate frequency amplifier; a second AM detector for detecting a signal from said wide band amplifier to produce a second AM detection output signal B; and a circuit for combining said first and second AM detection output signals A and B at a coefficient a M to produce an AM detection output A(1-a M )+a M B, where, 0≦a M ≦1, the coefficient a M being variable in said combining circuit.
Claim 3
Dependent Claim
47 words
An AM receiver according to claim 1, further including a circuit for detecting a magnitude of the received signal level from either said wide or narrow band intermediate frequency amplifier and wherein said coefficient a M is varied in response to an output of said detecting circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-30 | 1989-12-30 | 1990-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-30 | 1993-12-30 | 1994-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-30 | 1997-12-30 | 1998-07-01 | $7700.00 | Window Closed / Lapsed |