US3992669A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio frequency protection circuit
Assignee: AG Communication Systems Corp
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Filing: 1975-08-29
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Granted: 1976-11-16
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Expires: 1995-08-29
Abstract
Abstract A diode switch device coupled between two circulators provides signal continuity around an active radio frequency circuit during a failure mode caused by a loss of local supply voltage. Under a normal nonfailed condition, the diode switch short circuits the bypass path, thereby preventing the input signal from bypassing the protected circuit. In the protected failure mode, the short circuit is removed and the input signal is conducted around the failed active circuit.
Inventors
- 👤 John Willson Dades
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:45
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/60; H03F3/608; H04; H04B; H04B1/00; H04B1/74; H04B1/745
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
182 words
A radio frequency protection circuit providing a bypass signal path around an active electrical circuit upon the loss of supply voltage, said protection circuit comprising: an input terminal for receiving an input RF signal; an output terminal for carrying out an output signal; an active electrical circuit having an input and output; a source of supply voltage; a first RF circulator having a first port connected to said input terminal, a second port, and a third port connected to the input of said active electrical circuit; a second RF circulator having a first port connected to the output of said active electrical circuit, a second port connected to said output terminal, and a third port; and protective circuit means having an input and output, said input coupled to the second port of said first RF circulator and said output coupled to the third port of said second RF circulator, providing an open circuit termination reflecting RF energy during periods of nonfailure of said supply voltage and providing a closed circuit termination conducting RF energy during periods of failure of said supply voltage.
Claim 2
Dependent Claim
182 words
A radio frequency protection circuit providing a bypass signal path around an active electrical circuit upon the loss of supply voltage, said protection circuit comprising: an input terminal for receiving an input RF signal; an output terminal for carrying out an output signal; an active electrical circuit having an input and output; a source of supply voltage; a first RF circulator having a first port connected to said input terminal, a second port, and a third port connected to the input of said active electrical circuit; a second RF circulator having a first port connected to the output of said active electrical circuit, a second port connected to said output terminal, and a third port; and protective circuit means having an input and output, said input coupled to the second port of said first RF circulator and said output coupled to the third port of said second RF circulator, providing an open circuit termination reflecting RF energy during periods of nonfailure of said supply voltage and providing a closed circuit termination conducting RF energy during periods of failure of said supply voltage.
Claim 3
Dependent Claim
26 words
A protection circuit as in claim 1 wherein said protection circuit means comprises a PIN diode forward biased during periods of nonfailure of said supply voltage.
Claim 4
Dependent Claim
16 words
A protection circuit as in claim 2 wherein said active electrical circuit comprises an RF amplifier.
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) | 1979-11-16 | 1980-05-17 | 1980-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-16 | 1984-05-17 | 1984-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-16 | 1988-05-17 | 1988-11-16 | $7700.00 | Window Closed / Lapsed |