Patent US5020003A successfully refreshed from Google Patents.
Patent US3710146A successfully refreshed from Google Patents.
US3710146A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency doubler circuit
Assignee: Sony Corp
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Filing: 1971-07-07
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Granted: 1973-01-09
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Expires: 1991-07-07
Abstract
Abstract A frequency doubler circuit including a differential amplifier supplied with a signal of a predetermined frequency, for example, a pilot signal of 19KHz contained in an FM stereophonic signal, a pair of rectifier circuits coupled to outputs of the differential amplifier to rectify the signal of the predetermined frequency and a combining circuit to combine the rectified signals, whereby a signal of a frequency twice that of the signal supplied to the differential amplifier is derived at the output terminal of the combining circuit.
Inventors
- 👤 M Ohsawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:59
CPC Classifications
H; H04; H04H; H04H40/00; H04H40/18; H04H40/27; H04H40/36; H04H40/45; H04H40/54; H03; H03B; H03B19/00; H03B19/06; H03B19/14; H03B19/16; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/1646; H04B1/1653
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
181 words
In a frequency doubler circuit for FM receivers receiving an FM stereophonic signal frequency-modulated by a composite signal composed of a sum signal of two audit signals, a suppressedcarrier amplitude-modulated signal of a difference signal of the two audio signals and a pilot signal having a frequency one-half that of the suppressed-carrier signal, the improvement comprising: A. a differential amplifier comprising: 1. first and second transistors connected to power supply terminals, 2. an input circuit supplied with the pilot signal, and 3. first and second output circuits to supply oppositelypolarized output signals corresponding to said pilot signal; B. tuning means coupled to said output circuits of said differential amplifier and tuned to the frequency of the pilot signal; C. first and second rectifying means comprising third and fourth transistors having their bases coupled to said output circuits of said differential amplifier and having their emittercollector circuits connected in parallel for rectifying the oppositely polarized pilot signals from said differential amplifier; and D. an output terminal coupled to said rectifying means for receiving the rectified output signals derived from said rectifying means.
Claim 2
Dependent Claim
181 words
In a frequency doubler circuit for FM receivers receiving an FM stereophonic signal frequency-modulated by a composite signal composed of a sum signal of two audit signals, a suppressedcarrier amplitude-modulated signal of a difference signal of the two audio signals and a pilot signal having a frequency one-half that of the suppressed-carrier signal, the improvement comprising: A. a differential amplifier comprising: 1. first and second transistors connected to power supply terminals, 2. an input circuit supplied with the pilot signal, and 3. first and second output circuits to supply oppositelypolarized output signals corresponding to said pilot signal; B. tuning means coupled to said output circuits of said differential amplifier and tuned to the frequency of the pilot signal; C. first and second rectifying means comprising third and fourth transistors having their bases coupled to said output circuits of said differential amplifier and having their emittercollector circuits connected in parallel for rectifying the oppositely polarized pilot signals from said differential amplifier; and D. an output terminal coupled to said rectifying means for receiving the rectified output signals derived from said rectifying means.
Claim 3
Dependent Claim
9 words
an input circuit supplied with the pilot signal, and
Claim 4
Dependent Claim
9 words
an input circuit supplied with the pilot signal, and
Claim 5
Dependent Claim
27 words
a series resonant circuit connected in parallel to said constant-current source device and tuned to the frequency of the pilot signal to by-pass the pilot signal, and
Claim 6
Dependent Claim
27 words
a series resonant circuit connected in parallel to said constant-current source device and tuned to the frequency of the pilot signal to by-pass the pilot signal, and
Claim 7
Dependent Claim
21 words
A frequency doubler circuit as claimed in claim 1, wherein the first and second transistors are operated into their saturation region.
Claim 8
Dependent Claim
99 words
first and second output circuits to supply oppositely-polarized output signals corresponding to said pilot signal; B. tuning means coupled to said output circuits of said differential amplifier and tuned to the frequency of the pilot signal; C. first and second rectifying means comprising third and fourth transistors having their bases coupled to said output circuits of said differential amplifier and having their emitter-collector circuits connected in parallel for rectifying the oppositely polarized pilot signals from said differential amplifier; and D. an output terminal coupled to said rectifying means for receiving the rectified output signals derived from said rectifying means.
Claim 9
Dependent Claim
99 words
first and second output circuits to supply oppositely-polarized output signals corresponding to said pilot signal; B. tuning means coupled to said output circuits of said differential amplifier and tuned to the frequency of the pilot signal; C. first and second rectifying means comprising third and fourth transistors having their bases coupled to said output circuits of said differential amplifier and having their emitter-collector circuits connected in parallel for rectifying the oppositely polarized pilot signals from said differential amplifier; and D. an output terminal coupled to said rectifying means for receiving the rectified output signals derived from said rectifying means.
Claim 10
Dependent Claim
20 words
means connected in series with said constant-current source device for amplifying the pilot signal when supplied with the composite signal.
Claim 11
Dependent Claim
20 words
means connected in series with said constant-current source device for amplifying the pilot signal when supplied with the composite signal.
Claim 12
Dependent Claim
110 words
A frequency doubler circuit as claimed in claim 2, wherein: A. said third and fourth transistors have their base electrodes connected to the collector electrodes of said first and second transistors, respectively; B. the emitter electrodes of said third and fourth transistors are connected directly to the same power supply terminal as the collectors of said first and second transistors; C. the collector electrodes of said third and fourth transIstors are connected directly together to form said output terminal; and D. said frequency doubler circuit comprises a rectifier connected in series between said same power supply terminal and said tuning means to enhance the rectification efficiency of said rectifier means.
Claim 13
Dependent Claim
29 words
A frequency doubler circuit as claimed in claim 1, further comprising: A. Means for applying the pilot signal to said input circuit of said differential amplifier, said means comprising:
Claim 14
Dependent Claim
36 words
A frequency doubler circuit as claimed in claim 4, wherein said constant-current source device comprises: A. A transistor; and B. A diode connected to said transistor for applying a predetermined base bias to its base electrode.
Claim 15
Dependent Claim
38 words
A frequency doubler circuit as claimed in claim 4, wherein the pilot signal amplifying means comprises: A. A transistor; and B. A Zener diode connected to said transistor for applying a predetermined base bias to its base electrode.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |