US3845392A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Beacon transmitter
Assignee: Nautical Electronic Laboratories Ltd
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Filing: 1973-11-21
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Granted: 1974-10-29
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Expires: 1993-11-21
Abstract
Abstract A radio transmitter system which utilizes solid state modular power amplifier branches connected in parallel. The amplifier branches are fed from an exciting stage via a splitter-isolator network. The outputs of the amplifier branches can be connected to a single antenna system via an isolating combining network which isolates each amplifier branch from the effects of the operating conditions of every other amplifier branch. The amplifier branches are wide band and have inherently stable phase characteristics. This wide band stable phase characteristic is obtained because each branch is designed to have the response of a low-pass filter having a cut-off frequency which is above the frequency range of the transmitter.
Inventors
- 👤 D Covill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:54
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/68; H; H03; H03F; H03F3/00; H03F3/20; H03F3/24; H03F3/245; H04; H04B; H04B1/00; H04B1/02; H04B1/04; H04B1/0483
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
226 words
A radio transmitter comprising a low power radio frequency source; a splitter-isolator means having a plurality of outputs and one input, said input being connected to said source; a plurality of amplifier branches each having an input and an output, each input being connected to one output of said splitter-isolator means in a 1-to-1 correspondence whereby each of said branches amplify said signal; a combiner means having inputs each connected to one output of said amplifier branch in a 1-to-1 correspondence and providing an output which is the sum of the amplifier branch outputs and an antenna means fed by the output of said combiner means, said combiner means and antenna forming a constant load, each amplifier branch being characterized in that it includes a power amplifier stage, said power amplifier stage having an input and an output and at least one transistor, said transistor having a grounded base electrode, the power amplifier stage input beinG connected to the emitter of said transistor via a matching transformer and an emitterswamping resistor; the collector of said transistor being connected to said load via a transformer; said transformer having a leakage inductance such that when taken with the collector capacitance of said transistor and the resistance of said load, exhibits the response of a low-pass filter having a cut-off frequency above the usable frequency range of the transmitter.
Claim 2
Dependent Claim
226 words
A radio transmitter comprising a low power radio frequency source; a splitter-isolator means having a plurality of outputs and one input, said input being connected to said source; a plurality of amplifier branches each having an input and an output, each input being connected to one output of said splitter-isolator means in a 1-to-1 correspondence whereby each of said branches amplify said signal; a combiner means having inputs each connected to one output of said amplifier branch in a 1-to-1 correspondence and providing an output which is the sum of the amplifier branch outputs and an antenna means fed by the output of said combiner means, said combiner means and antenna forming a constant load, each amplifier branch being characterized in that it includes a power amplifier stage, said power amplifier stage having an input and an output and at least one transistor, said transistor having a grounded base electrode, the power amplifier stage input beinG connected to the emitter of said transistor via a matching transformer and an emitterswamping resistor; the collector of said transistor being connected to said load via a transformer; said transformer having a leakage inductance such that when taken with the collector capacitance of said transistor and the resistance of said load, exhibits the response of a low-pass filter having a cut-off frequency above the usable frequency range of the transmitter.
Claim 3
Dependent Claim
136 words
A transmitter according to claim 1 wherein each amplifier branch further includes at least one additional power amplifier stage connected in cascade with the first mentioned power amplifier stage, said additional power amplifier stage having an input and an output and including at least one transistor having a grounded base electrode; the input of said additional stage being connected to the emitter of said transistor via an emitter-swamping resistor, the collector of said transistor being connected to a load via a transformer, the load being the input impedance of the succeeding power amplifier stage, the leakage inductance of said transformer being such that when taken with the collector capacitance of said transistor and the resistance of said load, exhibits the response of a low-pass filter having a cut-off frequency above the usable range of said transmitter.
Claim 4
Dependent Claim
31 words
A radio transmitter according to claim 1 wherein said combiner means is an isolating hybrid combining network arranged so that the output of each of said amplifier branches is mutually isolated.
Claim 5
Dependent Claim
41 words
A radio transmitter according to claim 3 additionally comprising a plurality of power supplies connected in a 1-to-1 correspondence with each of said amplifier branches, each of said power supplies supplying electrical energy to an associated one of said amplifier branches.
Claim 6
Dependent Claim
105 words
A transmitter according to claim 1 wherein said splitter-isolator is comprised of a plurality of resistors, said resitors all being connected at one end to a common point, said common point being connected to said RF signal source, the other end of each resistor being connected to a corresponding input of each amplifier branch in a 1-to-1 correspondence, said RF source having a source resistance and each of said amplifier branches having an input resistance wherein the resistance of each of said plurality of resistors is greater than the source resistance or the input resistance to thereby mutually isolate the input of each amplifier branch.
References Cited (Backward Citations)
US1801870A
Cited
US3202940A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |