US4853972A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio transceiver including an antenna switching circuit capable of changing reception sensitivity
Assignee: NEC Corp
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Filing: 1987-04-07
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Granted: 1989-08-01
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Expires: 2007-04-07
Abstract
Abstract A radio transceiver having a plurality of switching means such that the reception sensitivity and transmission level of the transceiver can be changed. An antenna switching circuit selectively couples the transmitter or receiver to the antenna in response to a transmit or receive mode. A first switch connects the antenna switching circuit to one of a plurality of different potential levels to control the switching of the antenna switching circuit. First and second potential levels are used to achieve first and second receive modes having different receive sensitivities, and a third potential level is used to achieve a transmit mode. A second switch selectively activates one of a first transmitter circuit providing transmission signals, a second transmitter circuit providing reduced transmission signals, and a receiver. A control circuit controls the switching of the first and second switch.
Inventors
- 👤 Hideki Ueda
- 👤 Sotoaki Babano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:59
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/44; H04B1/06; H04B1/10; H04B1/109
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
69 words
A radio transceiver comprising an antenna, a transmitter, a receiver, an antenna switching circuit including switching diodes for coupling said transmitter and said receiver to said antenna in response to a transmit mode and a receive mode, respectively, and means for changing the resistances of said switching diodes in response to another receive mode to reduce the level of a received signal supplied from said antenna to said receiver.
Claim 2
Dependent Claim
69 words
A radio transceiver comprising an antenna, a transmitter, a receiver, an antenna switching circuit including switching diodes for coupling said transmitter and said receiver to said antenna in response to a transmit mode and a receive mode, respectively, and means for changing the resistances of said switching diodes in response to another receive mode to reduce the level of a received signal supplied from said antenna to said receiver.
Claim 3
Dependent Claim
113 words
A radio transceiver comprising an antenna, a transmitter, a receiver and an antenna switching circuit including first and second switching diodes, first means for giving a high resistance to said switching diodes by providing a first bias to said switching diodes in a receive mode to couple said antenna to said receiver, second means for giving a low resistance to said switching diodes by providing a second bias to said switching diodes in a transmit mode to couple said transmitter to said antenna, and third means for giving a resistance lying between said high and low resistances to said diodes by providing a third bias to said switching diode in another receive mode.
Claim 4
Dependent Claim
113 words
A radio transceiver comprising an antenna, a transmitter, a receiver and an antenna switching circuit including first and second switching diodes, first means for giving a high resistance to said switching diodes by providing a first bias to said switching diodes in a receive mode to couple said antenna to said receiver, second means for giving a low resistance to said switching diodes by providing a second bias to said switching diodes in a transmit mode to couple said transmitter to said antenna, and third means for giving a resistance lying between said high and low resistances to said diodes by providing a third bias to said switching diode in another receive mode.
Claim 5
Dependent Claim
25 words
A radio transceiver as claimed in claim 2, comprising means for selecting one of said first and third means in response to a control signal.
Claim 6
Dependent Claim
30 words
A radio transceiver as claimed in claim 3, wherein said control signal comprises a signal representative of the intensity of a radio signal received in one of said receive modes.
Claim 7
Dependent Claim
17 words
A radio transceiver as claimed in claim 3, comprising key board means for generating said control signal.
Claim 8
Dependent Claim
24 words
A radio transceiver as claimed in claim 2, comprising means for varying the output level of said transmitter in response to a control signal.
Claim 9
Dependent Claim
17 words
A radio transceiver as claimed in claim 6, comprising key board means for generating said control signal.
Claim 10
Dependent Claim
34 words
A radio receiver as claimed in claim 6, comprising means for selecting one of said first and third means in response to another control signal representative of the intensity of a received radio signal.
Claim 11
Dependent Claim
169 words
A radio transceiver including: an antenna, a transmitter, a receiver, and an antenna switching circuit for selectively coupling said transmitter and said receiver to said antenna in response to a transmit mode and a receive mode, respectively the antenna switching circuit including: a first diode coupled between said antenna and said transmitter, a second diode and an inductor connected in series between a point of fixed potential and the junction of said antenna and said first diode, and means for coupling said receiver to the junction of said second diode and said inductor, and means for changing the resistances of said first and second diodes in response to a control signal to couple said antenna to said transmitter in a transmit mode, to couple said antenna to said receiver in first and second receive modes, a receive signal being supplied from said antenna to said receiver in said first receive mode, and a received signal having a reduced level being supplied to said receiver in said second receive mode.
Claim 12
Dependent Claim
169 words
A radio transceiver including: an antenna, a transmitter, a receiver, and an antenna switching circuit for selectively coupling said transmitter and said receiver to said antenna in response to a transmit mode and a receive mode, respectively the antenna switching circuit including: a first diode coupled between said antenna and said transmitter, a second diode and an inductor connected in series between a point of fixed potential and the junction of said antenna and said first diode, and means for coupling said receiver to the junction of said second diode and said inductor, and means for changing the resistances of said first and second diodes in response to a control signal to couple said antenna to said transmitter in a transmit mode, to couple said antenna to said receiver in first and second receive modes, a receive signal being supplied from said antenna to said receiver in said first receive mode, and a received signal having a reduced level being supplied to said receiver in said second receive mode.
Claim 13
Dependent Claim
146 words
A radio transceiver comprising: an antenna; a transmitter; a receiver; an antenna switching circuit for selectively coupling said transmitter and said receiver to said antenna in response to a transmit mode respectively and a receive mode, respectively; first switching means for connecting said antenna switching circuit to one of a first, second and third potential, said first potential for causing said antenna switching circuit to selectively couple said antenna to said receiver such that a received signal can be applied to said receiver in a first receive mode, said second potential for causing said antenna switching circuit to selectively couple said antenna to said receiver such that a received signal of reduced level can be applied to said receiver in a second receive mode, and said third potential for causing said antenna switching circuit to selectively couple said antenna to said transceiver in a transmit mode.
Claim 14
Dependent Claim
146 words
A radio transceiver comprising: an antenna; a transmitter; a receiver; an antenna switching circuit for selectively coupling said transmitter and said receiver to said antenna in response to a transmit mode respectively and a receive mode, respectively; first switching means for connecting said antenna switching circuit to one of a first, second and third potential, said first potential for causing said antenna switching circuit to selectively couple said antenna to said receiver such that a received signal can be applied to said receiver in a first receive mode, said second potential for causing said antenna switching circuit to selectively couple said antenna to said receiver such that a received signal of reduced level can be applied to said receiver in a second receive mode, and said third potential for causing said antenna switching circuit to selectively couple said antenna to said transceiver in a transmit mode.
Claim 15
Dependent Claim
30 words
A radio transceiver as claimed in claim 10, wherein said transmitter produces one of a plurality of transmission signals of a plurality of levels in response to a control signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-31 | 1993-01-30 | 1993-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-31 | 1997-01-30 | 1997-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-31 | 2001-01-30 | 2001-08-01 | $7700.00 | Window Closed / Lapsed |