US4928072A
Expired / Lapsed
US
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Amplifier having suppressed spurious frequency components
Assignee: Raytheon Co
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Filing: 1989-07-05
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Granted: 1990-05-22
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Expires: 2009-07-05
Abstract
Abstract A circuit for the suppression of spurious frequency components for use in cascaded class C common base transistor amplifiers. The circuit uses a capacitor and shunt diode connected in series between emitter and ground of each stage to slow the pulse falltime and thereby eliminate spurious frequencies resulting from parasitic-caused ringing. The cathode-to-capacitor junction is pulsed through an RF choke at the pulse repetition frequency by a pulse generator. This effectively replaces the fast trailing edge of the RF pulse with the slower turn-on time of the PIN diode circuit. The resulting slower falltime eliminates spurious frequency production that normally occurs at each stage of cascaded amplifiers.
Inventors
- 👤 John C. Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:01
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/189; H03F3/19; H03F3/60; H03F3/602
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
40 words
In combination: an amplifier having input and output terminals; means coupled to said amplifier input terminal for generating pulses of RF energy; and means for increasingly reflecting said RF energy from said amplifier input terminal during each of said pulses.
Claim 2
Dependent Claim
40 words
In combination: an amplifier having input and output terminals; means coupled to said amplifier input terminal for generating pulses of RF energy; and means for increasingly reflecting said RF energy from said amplifier input terminal during each of said pulses.
Claim 3
Dependent Claim
29 words
The combination according to claim 1 wherein said amplifier comprises a transistor, and wherein said input and output terminals comprise, respectively, the emitter and collector electrodes of said transistor.
Claim 4
Dependent Claim
31 words
The combination according to claim 2 further including biasing means for providing a bias current through said transistor, said bias current enabling operation of said amplifier in the class C mode.
Claim 5
Dependent Claim
25 words
The combination according to claim 3 wherein said biasing means includes a bias current path for conducting said bias current between first and second potentials.
Claim 6
Dependent Claim
24 words
The combination according to claim 4 wherein said bias current path includes means for isolating said RF energy from said first and second potentials.
Claim 7
Dependent Claim
28 words
The combination according to claim 5 wherein said isolating means includes a stub having an effective electrical length of one quarter of the wavelength of said RF energy.
Claim 8
Dependent Claim
51 words
The combination according to claim 1 wherein said means for generating pulses of RF energy comprises: source means for providing a continuous RF signal; first pulse signal generating means; and means for mixing an RF signal from said source means and a pulse signal from said first pulse signal generating means.
Claim 9
Dependent Claim
54 words
The combination according to claim 7 wherein said reflecting means includes second pulse signal generating means responsive to pulses from said first pulse signal generating means, wherein pulses from said second pulse signal generating means are delayed by a predetermined time duration from the occurrences of pulses from said first pulse signal generating means.
Claim 10
Dependent Claim
52 words
The combination according to claim 8 wherein said reflecting means further includes a diode coupled to said second pulse signal generating means and to said amplifier input terminal, said diode responsive to pulses from said second pulse signal generating means for being driven from a reverse biased state to a conductive state.
Claim 11
Dependent Claim
33 words
The combination according to claim 9 wherein said diode switches from said reverse biased state to said conductive state during a time period substantially longer than the falltime of said RF energy pulses.
Claim 12
Dependent Claim
62 words
In combination: an amplifier having input and output terminals; means coupled to said amplifier input terminal for generating pulses of RF energy; and means for providing time-varying bias voltage at said amplifier input terminal during each of said RF pulses, said bias voltage providing means including means for increasingly reflecting said RF energy from said input terminal as said bias voltage decreases.
Claim 13
Dependent Claim
62 words
In combination: an amplifier having input and output terminals; means coupled to said amplifier input terminal for generating pulses of RF energy; and means for providing time-varying bias voltage at said amplifier input terminal during each of said RF pulses, said bias voltage providing means including means for increasingly reflecting said RF energy from said input terminal as said bias voltage decreases.
Claim 14
Dependent Claim
29 words
The combination according to claim 11 wherein said amplifier comprises a transistor, and wherein said input and output terminals comprise, respectively, the emitter and collector electrodes of said transistor.
Claim 15
Dependent Claim
31 words
The combination according to claim 12 further including biasing means for providing a bias current through said transistor, said bias current enabling operation of said amplifier in the class C mode.
Claim 16
Dependent Claim
25 words
The combination according to claim 13 wherein said biasing means includes a bias current path for conducting said bias current between first and second potentials.
Claim 17
Dependent Claim
24 words
The combination according to claim 14 wherein said bias current path includes means for isolating said RF energy from said first and second potentials.
Claim 18
Dependent Claim
28 words
The combination according to claim 15 wherein said isolating means includes a stub having an effective electrical length of one quarter of the wavelength of said RF energy.
Claim 19
Dependent Claim
51 words
The combination according to claim 11 wherein said means for generating pulses of RF energy comprises: source means for providing a continuous RF signal; first pulse signal generating means; and means for mixing an RF signal from said source means and a pulse signal from said first pulse signal generating means.
Claim 20
Dependent Claim
58 words
The combination according to claim 17 wherein said means for providing time-varying bias voltage includes second pulse signal generating means responsive to pulses from said first pulse signal generating means, wherein pulses from said second pulse signal generating means are delayed by a predetermined time duration from the occurrences of pulses from said first pulse signal generating means.
Claim 21
Dependent Claim
56 words
The combination according to claim 18 wherein said means for providing time-varying bias voltage further includes a diode coupled to said second pulse signal generating means and to said amplifier input terminal, said diode responsive to pulses from said second pulse signal generating means for being driven from a reverse biased state to a conductive state.
Claim 22
Dependent Claim
33 words
The combination according to claim 19 wherein said diode switches from said reverse biased state to said conductive state during a time period substantially longer than the falltime of said RF energy pulses.
Claim 23
Dependent Claim
86 words
An amplifier comprising: a transistor having input and output terminals; means coupled to said transistor input terminal for generating pulses of RF energy; means for generating a signal pulse during each of said RF pulses, said signal pulse having a signal level transition time substantially greater than the falltime of said RF pulse; and means for coupling said signal pulse generating means to said transistor input terminal and for increasingly reflecting said RF energy from said transistor input terminal during said transition of said signal pulse.
Claim 24
Dependent Claim
86 words
An amplifier comprising: a transistor having input and output terminals; means coupled to said transistor input terminal for generating pulses of RF energy; means for generating a signal pulse during each of said RF pulses, said signal pulse having a signal level transition time substantially greater than the falltime of said RF pulse; and means for coupling said signal pulse generating means to said transistor input terminal and for increasingly reflecting said RF energy from said transistor input terminal during said transition of said signal pulse.
Claim 25
Dependent Claim
22 words
The amplifier according to claim 21 wherein said input and output terminals comprise, respectively, the emitter and collector electrodes of said transistor.
Claim 26
Dependent Claim
31 words
The amplifier according to claim 22 further including biasing means for providing a bias current through said transistor, said bias current enabling operation of said amplifier in the class C mode.
Claim 27
Dependent Claim
51 words
The amplifier according to claim 21 wherein said means for generating pulses of RF energy comprises: source means for providing a continuous RF signal; second signal pulse generating means; and means for mixing an RF signal from said source means and a signal pulse from said second signal pulse generating means.
Claim 28
Dependent Claim
53 words
The amplifier according to claim 24 wherein said first-mentioned signal pulse generating means is responsive to pulse signals from said second signal pulse generating means, wherein pulses from said first-mentioned signal pulse generating means are delayed by a predetermined time duration from the occurrences of pulses from said second signal pulse generating means.
Claim 29
Dependent Claim
48 words
The amplifier according to claim 25 further including a diode coupled to said first-amplifier signal pulse generating means and to said amplifier input terminal, said diode responsive to pulses from said first-mentioned signal pulse generating means for being driven from a reverse biased state to a conductive state.
Claim 30
Dependent Claim
33 words
The amplifier according to claim 26 wherein said diode switches from said reverse biased state to said conductive state during a time period substantially longer than the falltime of said RF energy pulses.
Claim 31
Dependent Claim
102 words
A multi-stage amplifier system comprising: a plurality of amplifiers disposed in a cascade configuration, wherein each amplifier in the final stage includes input and output terminals, each of said final stage amplifiers being coupled to an amplifier in the previous stage and receiving pulses of RF energy therefrom at their input terminals; and means for generating a time-varying bias voltage at each of said final stage amplifier input terminals during each of said RF pulses, said bias voltage generating means including means for increasingly reflecting said RF energy from each of said final stage amplifier input terminals of said bias voltage decreases.
Claim 32
Dependent Claim
102 words
A multi-stage amplifier system comprising: a plurality of amplifiers disposed in a cascade configuration, wherein each amplifier in the final stage includes input and output terminals, each of said final stage amplifiers being coupled to an amplifier in the previous stage and receiving pulses of RF energy therefrom at their input terminals; and means for generating a time-varying bias voltage at each of said final stage amplifier input terminals during each of said RF pulses, said bias voltage generating means including means for increasingly reflecting said RF energy from each of said final stage amplifier input terminals of said bias voltage decreases.
References Cited (Backward Citations)
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