US4864642A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Space diversity receiving system
Assignee: Pioneer Corp
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Filing: 1988-04-01
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Granted: 1989-09-05
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Expires: 2008-04-01
Abstract
Abstract A space diversity system capable of operating accurately over a wide range of received input electric field strengths. With a middle or high received electric field strength, a search operation for the antenna with the highest strength is commenced in response to noise detected in the output of the antenna presently selected. With a low received electric field strength, the search operation is carried out in response to noise such as white noise at all times.
Inventors
- 👤 Eizi Ueno
- 👤 Masami Takayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:12
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0802; H04B7/0805; H04B7/0814; H04B7/0831
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
135 words
A space diversity receiving system in which, of a plurality of antennas, a one highest in received electric field strength is selected, and the output thereof is applied to an FM receiver, comprising: level detecting means for detecting a received electric field strength of a selected antenna from among said plurality of antennas; AC component separating means for separating an AC component from an output of said level detection means; trigger signal generating means for producing a trigger signal when, for a high or middle level of received electric field strength, an abrupt change occurs in said received electric field strength, and for a low level of received electric field strength, randomly and continuously; and antenna selecting means for selecting an antenna presently highest in received electric field strength in response to said trigger signal.
Claim 2
Dependent Claim
135 words
A space diversity receiving system in which, of a plurality of antennas, a one highest in received electric field strength is selected, and the output thereof is applied to an FM receiver, comprising: level detecting means for detecting a received electric field strength of a selected antenna from among said plurality of antennas; AC component separating means for separating an AC component from an output of said level detection means; trigger signal generating means for producing a trigger signal when, for a high or middle level of received electric field strength, an abrupt change occurs in said received electric field strength, and for a low level of received electric field strength, randomly and continuously; and antenna selecting means for selecting an antenna presently highest in received electric field strength in response to said trigger signal.
Claim 3
Dependent Claim
84 words
The space diversity receiving system of claim 1, wherein said trigger signal generating means comprises: an AGC amplifier; a capacitor coupling a signal received from a presently selected antenna to a signal input of said AGC amplifier; means for rectifying an output of said AGC amplifier; a monostable multivibrator having a trigger input coupled to an output of said rectifying means; and differentiating means coupled to an output of said monostable multivibrator, said trigger signal being produced on an output of said differentiating means.
Claim 4
Dependent Claim
55 words
The space diversity receiving system of claim 2, further comprising: a first low-pass filter coupled between said output of said rectifying means and a first gain control input of said AGC amplifier; and a second low-pass filter coupled between said output of said monostable multivibrator and a second gain control input of said AGC amplifier.
Claim 5
Dependent Claim
67 words
The space diversity receiving system of claim 1, wherein said antenna selecting means comprises: level comparing means; pulse generating means comprising a plurality of cascade-connected monostable multivibrators; antenna switching means for successively coupling said antennas to said level comparing means in response to outputs of said pulse generating means; and means for selecting one of said antennas in response to an output of said level comparing means.
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) | 1992-09-04 | 1993-03-06 | 1993-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-04 | 1997-03-06 | 1997-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-04 | 2001-03-06 | 2001-09-05 | $7700.00 | Window Closed / Lapsed |