Patent US3882425A successfully refreshed from Google Patents.
US3882425A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear microwave modulator
Assignee: Boeing Co
•
Filing: 1973-08-27
•
Granted: 1975-05-06
•
Expires: 1993-08-27
Abstract
Abstract An apparatus for linearly modulating a microwave carrier signal by means of a modulation signal control loop. An RF carrier signal is modulated by a current-controlled pin diode, which in turn is driven by the output of the control loop. A diode detects the modulation present at the output of the apparatus and this detected signal is fed back to an error amplifier where it is compared with a predetermined modulating signal. The output of the error amplifier is applied as a control signal to the pin diode modulator. A linear amplitude modulation of the RF carrier is thus achieved by applying a compensating nonlinear modulator drive signal to the nonlinear pin diode modulator. A temperature compensating circuit is also provided, wherein a diode identical to the detecting diode is connected between ground and the predetermined modulating signal circuit. This results in both inputs to the error amplifier being equally affected by changes in environmental temperature, and results in a pin diode drive signal which is independent of fluctuations in detector diode response due to temperature change.
Inventors
- 👤 Darrell A Briley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:13
CPC Classifications
H; H03; H03C; H03C1/00; H03C1/02; H03C1/06; H03C7/00; H03C7/02; H03C7/025; H03C7/027
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
124 words
A microwave modulator, comprising in combination: means for generating a carrier signal; means for generating a reference signal; modulator means responsive to a modulator drive signal and operative to produce a modulated output signal comprising said carrier signal and a modulation component; circuit means for compensating for variations in the response of said detecting means due to environmental temperature changes; means having an output for detecting said modulation component; means coupled to said modulation signal generating means and said detecting means for determining a signal difference between said reference signal and said modulation component, and operative to derive said modUlator drive signal, which modulator drive signal is a function of said difference signal; and, means applying said modulator drive signal to said modulator means.
Claim 2
Dependent Claim
124 words
A microwave modulator, comprising in combination: means for generating a carrier signal; means for generating a reference signal; modulator means responsive to a modulator drive signal and operative to produce a modulated output signal comprising said carrier signal and a modulation component; circuit means for compensating for variations in the response of said detecting means due to environmental temperature changes; means having an output for detecting said modulation component; means coupled to said modulation signal generating means and said detecting means for determining a signal difference between said reference signal and said modulation component, and operative to derive said modUlator drive signal, which modulator drive signal is a function of said difference signal; and, means applying said modulator drive signal to said modulator means.
Claim 3
Dependent Claim
37 words
An apparatus in accordance with claim 1, including means for controlling said detected modulation component, wherein said controlling means includes means operative to separately vary said DC portion and said AC portion of said detected modulation component.
Claim 4
Dependent Claim
42 words
An apparatus in accordance with claim 1, wherein said determining means is an error amplifier having two input connections, and an output connection coupled to said modulation means, said summing means providing one input, and said controlling means providing the other input.
Claim 5
Dependent Claim
25 words
An apparatus in accordance with claim 3, wherein said temperature compensating means includes a diode, having substantial similar temperatures response characteristics as said detecting means.
Claim 6
Dependent Claim
56 words
An apparatus in accordance with claim 4, wherein said controlling means includes a variable resistance DC signal path, a variable low pass filter, and a variable high pass filter, said DC signal path, said low pass filter and said high pass filter being coupled between said detecting means and said other input of said error amplifier.
Claim 7
Dependent Claim
38 words
An apparatus in accordance with claim 5, wherein said modulator means includes a PIN diode, which PIN diode is operative to attenuate said carrier signal in accordance with said modulator drive signal to produce said modulated output signal.
Claim 8
Dependent Claim
43 words
An apparatus in accordance with claim 6, wherein said modulator means includes means for isolating said modulator from said detecting means and said carrier generator means in such a manner that reflected power from said PIN diode is dissipated in said isolating means.
Claim 9
Independent Claim
117 words
An apparatus for linearly modulating a microwave frequency carrier signal, comprising: modulator means having a nonlinear modulation characteristic for modulating said carrier signal with a modulation signal to produce a modulated carrier signal, said modulated carrier signal comprising a carrier component and a modulation component, said modulation component being related to said modulation signal by the nonlinear characteristic of said modulator means; means for detecting said modulation component; means for generating a reference signal; means comparing said reference signal and said modulation component and producing an output signal proportional to a difference between said reference signal and said modulation component, said output signal being said modulation signal; and, means applying said output signal to said modulator means.
Claim 10
Independent Claim
117 words
An apparatus for linearly modulating a microwave frequency carrier signal, comprising: modulator means having a nonlinear modulation characteristic for modulating said carrier signal with a modulation signal to produce a modulated carrier signal, said modulated carrier signal comprising a carrier component and a modulation component, said modulation component being related to said modulation signal by the nonlinear characteristic of said modulator means; means for detecting said modulation component; means for generating a reference signal; means comparing said reference signal and said modulation component and producing an output signal proportional to a difference between said reference signal and said modulation component, said output signal being said modulation signal; and, means applying said output signal to said modulator means.
Claim 11
Dependent Claim
24 words
An apparatus of claim 8, including circuit means for compensating for variations in the response of said detecting means due to environmental temperature changes.
Claim 12
Dependent Claim
13 words
An apparatus of claim 8, wherein said modulator means is a PIN diode.
Claim 13
Dependent Claim
71 words
An apparatus of claim 9, wherein said comparing means includes two input connections and further includes means applying the detected modulation component to one of said two input connections of said comparator, and means coupling said compensating means and said reference signal means to the other of said two input connections, such that changes in environmental temperature affect equally the signals at both said two input connections of said comparing means.
Claim 14
Dependent Claim
35 words
An apparatus of claim 10, wherein said detecting means is a diode, and wherein said compensating means includes a diode, and further includes means for substantially identically biasing said detector diode and said compensating diode.
Claim 15
Dependent Claim
61 words
An apparatus of claim 12, wherein said compensating diode has a temperature dependent output and includes a source of DC voltage and means for summing said temperature dependent output with said DC voltage to form a composite signal, and further includes means summing said reference signal with said composite signal at said other of two input connections of said comparing means.
Claim 16
Dependent Claim
24 words
An apparatus of cLaim 8, including signal level control means coupled between said detecting means and said one input connection of said comparing means.
Claim 17
Dependent Claim
43 words
An apparatus of claim 14, wherein said detected modulation component includes a DC portion and an AC portion, and wherein said signal level control means includes means for varying the magnitude of said DC portion and said AC portion independent of each other.
Claim 18
Dependent Claim
52 words
An apparatus of claim 9, wherein said means for varying the DC portion is a variable resistance means, and wherein said means for varying the AC portion includes a high pass filter section and a low pass filter section, each of said high pass and low pass filter sections including variable resistances.
References Cited (Backward Citations)
US3200336A
Cited
US3162801A
Cited
US3217271A
Cited
US3605018A
Cited
US3668533A
Cited
US3662290A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |