US4725780A
Expired / Lapsed
US
⏱️ 0.0 years remaining
RF field generator and detector
Assignee: Mitsubishi Electric Corp
•
Filing: 1985-10-18
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Granted: 1988-02-16
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Expires: 2005-10-18
Abstract
Abstract An RF field generator and detector comprising an RF coil having an inductance and at least one conductor which includes at least first and second separated parts arranged to form stray capacitance between them, capacitors for impedance matching which are connected to the RF coil, and a balanced-to-unbalanced transformer by which a balanced load composed of the RF coil and the capacitors is coupled to an unbalanced RF transmitter and receiver, the stray capacitance being adjusted thereby to equivalently reduce the inductance of the RF coil.
Inventors
- 👤 Kiyoshi Yoda
- 👤 Satoshi Fujimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:03
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/36; G01R33/3628
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
82 words
An RF field generator and detector comprising: an RF coil having an inductance and at least one conductor including at least first and second separated parts arranged to form stray capacitance therebetween; capacitors for impedance matching which are connected to said RF coil; and a balanced-to-unbalanced transformer by which a balanced load comprising said RF coil and said capacitors is coupled to an unbalanced RF transmitter and receiver, the stray capacitance being adjusted to equivalently reduce the inductance of said RF coil.
Claim 2
Dependent Claim
82 words
An RF field generator and detector comprising: an RF coil having an inductance and at least one conductor including at least first and second separated parts arranged to form stray capacitance therebetween; capacitors for impedance matching which are connected to said RF coil; and a balanced-to-unbalanced transformer by which a balanced load comprising said RF coil and said capacitors is coupled to an unbalanced RF transmitter and receiver, the stray capacitance being adjusted to equivalently reduce the inductance of said RF coil.
Claim 3
Dependent Claim
18 words
An RF field generator and detector according to claim 1 wherein said RF coil comprises a saddle-shaped coil.
Claim 4
Dependent Claim
37 words
An RF field generator and detector according to claim 1 further comprising: an electric insulator member positioned between said first and second separated parts, and wherein said at least first and second separated parts comprise metal members.
Claim 5
Dependent Claim
26 words
An RF field generator and detector according to claim 1 wherein said balanced-to-unbalanced transformer comprises a transmission line which has an electrical length of 1/2 wavelength.
Claim 6
Dependent Claim
18 words
An RF field generator and detector according to claim 4 wherein said transmission line comprises a coaxial cable.
Claim 7
Dependent Claim
22 words
An RF field generator and detector according to claim 1 wherein said capacitors for impedance matching are arranged in a balanced form.
Claim 8
Dependent Claim
90 words
An RF field generator and detector comprising: an RF coil having an inductance and at least one conductor including at least first and second separated parts arranged to form stray capacitance therebetween; capacitors for impedance matching; an impedance transformer which couples said RF coil and said capacitors; and a balanced-to-unbalanced transformer by which a balanced load comprising said RF coil, said capacitors, and said impedance transformer is coupled to an unbalanced RF transmitter and receiver, the stray capacitance being adjusted to equivalently render an impedance of said RF coil capacitive.
Claim 9
Dependent Claim
90 words
An RF field generator and detector comprising: an RF coil having an inductance and at least one conductor including at least first and second separated parts arranged to form stray capacitance therebetween; capacitors for impedance matching; an impedance transformer which couples said RF coil and said capacitors; and a balanced-to-unbalanced transformer by which a balanced load comprising said RF coil, said capacitors, and said impedance transformer is coupled to an unbalanced RF transmitter and receiver, the stray capacitance being adjusted to equivalently render an impedance of said RF coil capacitive.
Claim 10
Dependent Claim
33 words
An RF field generator and detector according to claim 7 wherein said impedance transformer comprises a transmission line which has an electrical length being at least 1/4 wavelength and less than 1/2 wavelength.
Claim 11
Dependent Claim
101 words
An RF field generator and detector comprising an RF coil having an inductance and at least one conductor including at least first and second separated parts arranged to form stray capacitance therebetween; capacitors for impedance matching which are connected to said RF coil; a balanced-to-unbalanced transformer by which a balanced load comprising said RF coil and said capacitors is coupled to an unbalanced RF transmitter and receiver; and an impedance transformer which is interposed between said balanced-to-unbalanced transformer and connection terminals for the RF transmitter and receiver, the stray capacitance being adjusted to equivalently reduce the inductance of said RF coil.
Claim 12
Dependent Claim
101 words
An RF field generator and detector comprising an RF coil having an inductance and at least one conductor including at least first and second separated parts arranged to form stray capacitance therebetween; capacitors for impedance matching which are connected to said RF coil; a balanced-to-unbalanced transformer by which a balanced load comprising said RF coil and said capacitors is coupled to an unbalanced RF transmitter and receiver; and an impedance transformer which is interposed between said balanced-to-unbalanced transformer and connection terminals for the RF transmitter and receiver, the stray capacitance being adjusted to equivalently reduce the inductance of said RF coil.
Claim 13
Dependent Claim
18 words
An RF field generator and detector according to claim 9 wherein said RF coil comprises a saddle-shaped coil.
Claim 14
Dependent Claim
37 words
An RF field generator and detector according to claim 9 further comprising: an electric insulator member positioned between said first and second separated parts, and wherein said at least first and second separated parts comprise metal members.
Claim 15
Dependent Claim
28 words
An RF field generator and detector according to claim 9 wherein said impedance transformer comprises a coaxial cable which has an electrical length substantially equal to 1/4 wavelength.
Claim 16
Dependent Claim
32 words
An RF field generator and detector according to claim 9 wherein said impedance transformer comprises a plurality of serially connected coaxial cables which have an electrical length substantially equal to 1/4 wavelength.
Claim 17
Dependent Claim
22 words
An RF field generator and detector according to claim 9 wherein said capacitors for impedance matching are arranged in a balanced form.
Claim 18
Dependent Claim
26 words
An RF field generator and detector according to claim 9 wherein said balanced-to-unbalanced transformer comprises a transmission line which has an electrical length of 1/2 wavelength.
Claim 19
Dependent Claim
18 words
An RF field generator and detector according to claim 15 wherein said transmission line comprises a coaxial cable.
Claim 20
Dependent Claim
29 words
An RF field generator and detector according to claim 9 wherein said balanced-to-unbalanced transformer comprises a Sperrtopf (wave trap) type transformer which has an electrical length of 1/4 wavelength.
Claim 21
Dependent Claim
28 words
An RF field generator and detector according to claim 9 wherein said balanced-to-unbalanced transformer comprises a branch conductor type transformer which has an electrical length of 1/4 wavelength.
Claim 22
Dependent Claim
112 words
An RF field generator and detector comprising: an RF coil having an inductance and at least one conductor including at least first and second separated parts arranged to form stray capacitance therebetween; capacitors for impedance matching; a first impedance transformer which couples said RF coil and said capacitors; a balanced-to-unbalanced transformer by which a balanced load comprising said RF coil, said capacitors, and said first impedance transformer is coupled to an unbalance RF transmitter and receiver; and a second impedance transformer which is interposed between said balanced-to-unbalanced transformer and connection terminals for the RF transmitter and receiver, the stray capacitance being adjusted to equivalently render an impedance of said RF coil capacitive.
Claim 23
Dependent Claim
112 words
An RF field generator and detector comprising: an RF coil having an inductance and at least one conductor including at least first and second separated parts arranged to form stray capacitance therebetween; capacitors for impedance matching; a first impedance transformer which couples said RF coil and said capacitors; a balanced-to-unbalanced transformer by which a balanced load comprising said RF coil, said capacitors, and said first impedance transformer is coupled to an unbalance RF transmitter and receiver; and a second impedance transformer which is interposed between said balanced-to-unbalanced transformer and connection terminals for the RF transmitter and receiver, the stray capacitance being adjusted to equivalently render an impedance of said RF coil capacitive.
Claim 24
Dependent Claim
34 words
An RF field generator and detector according to claim 19 wherein said first impedance transformer comprises a transmission line which has an electrical length being at least 1/4 wavelength and less than 1/2 wavelength.
Claim 25
Dependent Claim
29 words
An RF field generator and detector according to claim 19 wherein said second impedance transformer comprises a coaxial cable which has an electrical length substantially equal to 1/4 wavelength.
Claim 26
Dependent Claim
33 words
An RF field generator and detector according to claim 19 wherein said second impedance transformer comprises a plurality of serially connected coaxial cables which have an electrical length substantially equal to 1/4 wavelength.
Claim 27
Dependent Claim
37 words
An RF field generator and detector according to claim 19 further comprising: an electric insulator member positioned between said first and second separated parts, and wherein said at least first and second separated parts comprise metal members.
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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) | 1991-02-15 | 1991-08-17 | 1992-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-15 | 1995-08-17 | 1996-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-15 | 1999-08-17 | 2000-02-16 | $7700.00 | Window Closed / Lapsed |