Patent US6496684B2 successfully refreshed from Google Patents.
US6496684B2
Expired / Lapsed
US
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SPST switch, SPDT switch, and communication apparatus using the SPDT switch
Assignee: Murata Manufacturing Co Ltd
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Filing: 2001-07-11
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Granted: 2002-12-17
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Expires: 2021-07-11
Abstract
Abstract An SPST switch having a small transmission loss and a small power consumption is provided. The drain and the source of an FET are connected to each other in series through an induction element and a capacitor element, one terminal of the capacitor element is connected to a first terminal, the other terminal is connected to a second terminal, the gate of the FET is connected to a control terminal, the capacitance of the capacitor element is made equal to the OFF capacitance of the FET, and the inductance of the induction element is set to be such a value that the induction element resonates at a signal frequency with the capacitor element.
Inventors
- 👤 Motoyasu Nakao
- 👤 Akihiro Sasabata
- 👤 Hiroaki Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:19
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/687; H03K17/693
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
184 words
A single pole double throw (SPDT) switch, comprising: a first terminal, a second terminal, and a control terminal; a field effect transistor (FET) having a gate connected to the control terminal, a drain connected to the first terminal, and a source, the FET exhibiting an OFF capacitance from drain to source; a capacitor element having a capacitance substantially equal to the OFF capacitance of the FET, the capacitor element having one end connected to the first terminal and another end connected to the second terminal; an induction element having one end connected to the source of the FET and another end connected to the second terminal, an inductance of the induction element being set such that it resonates with the capacitor element at a signal frequency; and a switching element having first and second signal terminals and a switching terminal, the first signal terminal being coupled to the third terminal, the second signal terminal being coupled to the first terminal and the switching terminal being coupled to the control terminal such that the switching element is turned on and off synchronously with the FET.
Claim 2
Dependent Claim
184 words
A single pole double throw (SPDT) switch, comprising: a first terminal, a second terminal, and a control terminal; a field effect transistor (FET) having a gate connected to the control terminal, a drain connected to the first terminal, and a source, the FET exhibiting an OFF capacitance from drain to source; a capacitor element having a capacitance substantially equal to the OFF capacitance of the FET, the capacitor element having one end connected to the first terminal and another end connected to the second terminal; an induction element having one end connected to the source of the FET and another end connected to the second terminal, an inductance of the induction element being set such that it resonates with the capacitor element at a signal frequency; and a switching element having first and second signal terminals and a switching terminal, the first signal terminal being coupled to the third terminal, the second signal terminal being coupled to the first terminal and the switching terminal being coupled to the control terminal such that the switching element is turned on and off synchronously with the FET.
Claim 3
Dependent Claim
38 words
The single pole double throw (SPDT) switch of claim 1 , wherein the switching element is an FET, the first and second signal terminals being either of a drain and source, and the switching terminal being a gate.
Claim 4
Dependent Claim
253 words
A communication apparatus, comprising: a single pole double throw (SPDT) switch, including: a first terminal, a second terminal, and a control terminal; a field effect transistor (FET) having a gate connected to the control terminal, a drain connected to the first terminal, and a source, the FET exhibiting an OFF capacitance from drain to source; a capacitor element having a capacitance substantially equal to the OFF capacitance of the FET, the capacitor element having one end connected to the first terminal and another end connected to the second terminal; an induction element having one end connected to the source of the FET and another end connected to the second terminal, an inductance of the induction element being set such that it resonates with the capacitor element at a signal frequency; and a switching element having first and second signal terminals and a switching terminal, the first signal terminal being coupled to the third terminal, the second signal terminal being coupled to the first terminal and the switching terminal being coupled to the control terminal such that the switching element is turned on and off synchronously with the FET; an antenna coupled to the first terminal; a receiving circuit coupled to the second terminal; a transmitting circuit coupled to the third terminal; and a control circuit coupled to the first and second control terminals and being operable to provide switching signals to the first and second FETs such that the transmitting and receiving circuits are alternatively coupled to the antenna through the SPDT switch.
Claim 5
Dependent Claim
253 words
A communication apparatus, comprising: a single pole double throw (SPDT) switch, including: a first terminal, a second terminal, and a control terminal; a field effect transistor (FET) having a gate connected to the control terminal, a drain connected to the first terminal, and a source, the FET exhibiting an OFF capacitance from drain to source; a capacitor element having a capacitance substantially equal to the OFF capacitance of the FET, the capacitor element having one end connected to the first terminal and another end connected to the second terminal; an induction element having one end connected to the source of the FET and another end connected to the second terminal, an inductance of the induction element being set such that it resonates with the capacitor element at a signal frequency; and a switching element having first and second signal terminals and a switching terminal, the first signal terminal being coupled to the third terminal, the second signal terminal being coupled to the first terminal and the switching terminal being coupled to the control terminal such that the switching element is turned on and off synchronously with the FET; an antenna coupled to the first terminal; a receiving circuit coupled to the second terminal; a transmitting circuit coupled to the third terminal; and a control circuit coupled to the first and second control terminals and being operable to provide switching signals to the first and second FETs such that the transmitting and receiving circuits are alternatively coupled to the antenna through the SPDT switch.
Claim 6
Dependent Claim
34 words
The communications apparatus of claim 3 , wherein the switching element is an FET, the first and second signal terminals being either of a drain and source, and the switching terminal being a gate.
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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) | 2005-12-16 | 2006-06-17 | 2006-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-12-16 | 2010-06-17 | 2010-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-12-16 | 2014-06-17 | 2014-12-17 | $7700.00 | Window Closed / Lapsed |