US3781883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dynamic range control system having amplitude restoration
Assignee: Raytheon Co
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Filing: 1972-03-10
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Granted: 1973-12-25
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Expires: 1992-03-10
Abstract
Abstract An automatic dynamic range control system that eliminates the effect of dynamic range limitations in the main radar channel and restores the signal amplitude prior to detection. A separate auxiliary measurement channel is provided in parallel with the main IF channel having a logarithmic amplifier or sequential detector with sufficient dynamic range to meet the signal informational requirements. During each range bin period, the IF signal in the auxiliary channel is quantized in amplitude above the predetermined dynamic range of the main channel within selected ranges of input signal level to form coded signals. The quantized levels are then utilized substantially in real time for attenuating the signal in the main IF channel to maintain that signal within the dynamic range limits of the channel. After the main channel signal is processed and passed through an analog to digital converter, the coded signal for each corresponding range bin is utilized to recombine a component to the attenuated signal so that the radar signal has its original amplitude modulations restored. Thus, the system allows reliable radar detection while at the same time overcoming the limitations of limited gain characteristics.
Inventors
- 👤 D Effinger
- 👤 N Evans
- 👤 V Estrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:25
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/28; G01S7/285; G01S7/34
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
138 words
A gain control system responsive to a radar signal having a predetermined range of signal amplitude comprising a radar channel responsive to said radar signal and having a predetermined dynamic range limitation, an auxiliary channel responsive to said radar signal and having a dynamic range at least equal to said predetermined range of signal amplitude, decoding means included in said auxiliary channel for developing coded signals representative of the signal amplitude in excess of the dynamic range of said radar channel, attenuating means included in said radar channel and responsive to said decoding means to attenuate the radar signal amplitude when it exceeds the dynamic range of the radar channel, and recombining means included in said radar channel subsequent to said attenuating means and responsive to said decoding means to restore the attenuated amplitude to said radar signal.
Claim 2
Dependent Claim
138 words
A gain control system responsive to a radar signal having a predetermined range of signal amplitude comprising a radar channel responsive to said radar signal and having a predetermined dynamic range limitation, an auxiliary channel responsive to said radar signal and having a dynamic range at least equal to said predetermined range of signal amplitude, decoding means included in said auxiliary channel for developing coded signals representative of the signal amplitude in excess of the dynamic range of said radar channel, attenuating means included in said radar channel and responsive to said decoding means to attenuate the radar signal amplitude when it exceeds the dynamic range of the radar channel, and recombining means included in said radar channel subsequent to said attenuating means and responsive to said decoding means to restore the attenuated amplitude to said radar signal.
Claim 3
Dependent Claim
17 words
The system of claim 1 in which said auxiliary channel includes a sequential detector providing logarithmic amplification.
Claim 4
Dependent Claim
34 words
The system of claim 2 in which said radar channel and said auxiliary channel respectively provide a linear signal and a logarithmic signal to said recombining means and said recombining means is a multiplier.
Claim 5
Dependent Claim
21 words
The system of claim 3 in which said recombining means includes encoding means for converting the coded signals to multiplying factors.
Claim 6
Dependent Claim
30 words
The system of claim 1 in which said radar channel and said auxiliary channel both provide logarithmic signals to said recombining means and said recombining means is a summing unit.
Claim 7
Dependent Claim
180 words
A dynamic range gain control system operative in a radar system having at least one main channel that has a dynamic range limitation, said radar system providing radar signals during each of a plurality of range bins to said main channel of a predetermined dynamic range of fluctuation comprising an auxiliary channel responsive to said radar signal and including logarithmic amplifier means having a dynamic range at least equal to the predetermined range of said radar signal, encoding means coupled to said logarithmic amplifier means for developing coded signals representative of predetermined ranges of amplitude of the radar signal above the dynamic range limitation of said main channel, attenuating means included in said main channel and responsive to said coded signals during each range bin to control the amplitude of said radar signal, and recombining means included in said main channel at a selected position subsequent to said attenuating means and coupled to said encoding means for increasing the amplitude of said radar signal during each range bin corresponding to the range bin that was attenuated by said attenuating means.
Claim 8
Dependent Claim
180 words
A dynamic range gain control system operative in a radar system having at least one main channel that has a dynamic range limitation, said radar system providing radar signals during each of a plurality of range bins to said main channel of a predetermined dynamic range of fluctuation comprising an auxiliary channel responsive to said radar signal and including logarithmic amplifier means having a dynamic range at least equal to the predetermined range of said radar signal, encoding means coupled to said logarithmic amplifier means for developing coded signals representative of predetermined ranges of amplitude of the radar signal above the dynamic range limitation of said main channel, attenuating means included in said main channel and responsive to said coded signals during each range bin to control the amplitude of said radar signal, and recombining means included in said main channel at a selected position subsequent to said attenuating means and coupled to said encoding means for increasing the amplitude of said radar signal during each range bin corresponding to the range bin that was attenuated by said attenuating means.
Claim 9
Dependent Claim
22 words
The system of claim 6 in which an analog to digital converter is coupled between said attenuating means and said recombining means.
Claim 10
Dependent Claim
34 words
The system of claim 7 in which the signals in said auxiliary channel and said main channel respectively apply logarithmic and linear signals to said recombining means and said recombining means is a multiplier.
Claim 11
Dependent Claim
33 words
The system of claim 7 in which the signals in said auxiliary channel and in said main channel applied to said recombining means are both logarithmic and said recombining means is a summer.
Claim 12
Dependent Claim
19 words
The system of claim 8 further including multiplier coding means coupled between said encoding means and said recombining means.
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) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |