US4955038A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-power RF receiver
Assignee: Maxim Integrated Products Inc
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Filing: 1988-12-09
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Granted: 1990-09-04
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Expires: 2008-12-09
Abstract
Abstract A RF receiver with extremely low standby power consumption. To minimize power consumption during standby, the analog input from the antenna circuit (including tank resonator) is connected directly to the inputs of a comparator. Preferably two comparators are used, each connected to a separate antenna. Thus, a signal loss due to antenna nulls will be minimized. Preferably a following stage decodes a pulse-width-modulated (or burst-length-modulated) signal. If the length of pulses substantially exceeds the expected maximum, the following stage provides a control signal to reduce the gain of the input comparators.
Inventors
- 👤 Robert D. Lee
- 👤 Robert W. Mounger
- 👤 John P. Heptig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:35
CPC Classifications
H; H04; H04W; H04W52/00; H04W52/02; H04W52/0209; H04W52/0261; H04W52/0274; H04W52/0277; H04W52/0287; H04W52/029; H04W52/0212; H04W52/0216; Y; Y02; Y02D; Y02D30/00; Y02D30/70
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
99 words
A low-power RF receiver, comprising: a battery; at least two antenna circuits, tuned to a predetermined reception frequency; at least two comparators, each having a respective pair of inputs directly connected to receive a low-level analog signal at said predetermined frequency from a respective one of said antenna circuits; at least one digital logic stage, connected to be driven by the output of a selected one of said comparators and to provide a full digital output corresponding to the voltage received at said selected comparator; said comparators and said logic stage being connected to be powered by said battery.
Claim 2
Dependent Claim
99 words
A low-power RF receiver, comprising: a battery; at least two antenna circuits, tuned to a predetermined reception frequency; at least two comparators, each having a respective pair of inputs directly connected to receive a low-level analog signal at said predetermined frequency from a respective one of said antenna circuits; at least one digital logic stage, connected to be driven by the output of a selected one of said comparators and to provide a full digital output corresponding to the voltage received at said selected comparator; said comparators and said logic stage being connected to be powered by said battery.
Claim 3
Dependent Claim
20 words
The receiver of claim 1, wherein said full digital output is at the same frequency as said low-level analog signal.
Claim 4
Dependent Claim
16 words
The receiver of claim 1, wherein said low-level analog signal has a frequency below 10 MHz.
Claim 5
Dependent Claim
16 words
The receiver of claim 1, wherein said low-level analog signal has a frequency below 1 MHz.
Claim 6
Dependent Claim
30 words
The receiver of claim 1, wherein each said antenna circuit has first and second output leads connected directly to said pair of inputs of a respective one of said comparators.
Claim 7
Dependent Claim
168 words
A low-power RF receiver, comprising: a battery; at least one antenna circuit, tuned to at least one predetermined reception frequency; at least one comparator, having a pair of inputs directly connected to receive a low-level analog signal at said predetermined frequency from said antenna circuit, wherein said comparator receives a standby current which is regulated by a current source, and wherein said current source comprises multiple current-source devices in parallel, and switching transistors which are connected in series with individual ones of said current-source devices, to enable or disable ones of said current-source devices; current-source-control logic, connected to control said switching transistors, and thereby enable or disable ones of said current-source devices, in accordance with signal detection characteristics seen at a later stage; and at least one digital logic stage, connected to be driven by the output of said comparator and provide a full digital output corresponding to the voltage received at said comparator; said comparator and said logic stage being connected to be powered by said battery.
Claim 8
Dependent Claim
168 words
A low-power RF receiver, comprising: a battery; at least one antenna circuit, tuned to at least one predetermined reception frequency; at least one comparator, having a pair of inputs directly connected to receive a low-level analog signal at said predetermined frequency from said antenna circuit, wherein said comparator receives a standby current which is regulated by a current source, and wherein said current source comprises multiple current-source devices in parallel, and switching transistors which are connected in series with individual ones of said current-source devices, to enable or disable ones of said current-source devices; current-source-control logic, connected to control said switching transistors, and thereby enable or disable ones of said current-source devices, in accordance with signal detection characteristics seen at a later stage; and at least one digital logic stage, connected to be driven by the output of said comparator and provide a full digital output corresponding to the voltage received at said comparator; said comparator and said logic stage being connected to be powered by said battery.
Claim 9
Dependent Claim
20 words
The receiver of claim 6, wherein said full digital output is at the same frequency as said low-level analog signal.
Claim 10
Dependent Claim
16 words
The receiver of claim 6, wherein said low-level analog signal has a frequency below 10 MHz.
Claim 11
Dependent Claim
16 words
The receiver of claim 6, wherein said low-level analog signal has a frequency below 1 MHz.
Claim 12
Dependent Claim
25 words
The receiver of claim 6, wherein said antenna circuit has first and second output leads connected directly to said pair of inputs of said comparator.
Claim 13
Dependent Claim
22 words
The receiver of claim 6, wherein said current source comprises at least 4 of said multiple current-source devices switchably connected in parallel.
Claim 14
Dependent Claim
26 words
The receiver of claim 6, wherein the widest of said current-source devices is at least four times as wide as the narrowest of said current-source devices.
References Cited (Backward Citations)
US4129855A
Cited
US4364043A
Cited
US4584709A
Cited
US4731879A
Cited
US4696058A
Cited
US4691202A
Cited
US4756023A
Cited
US4783658A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-03 | 1994-03-05 | 1994-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-03 | 1998-03-05 | 1998-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-03 | 2002-03-05 | 2002-09-04 | $7700.00 | Window Closed / Lapsed |