Patent US5710997A successfully refreshed from Google Patents.
US5710997A
Expired / Lapsed
US
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Superheterodyne receiver apparatus
Assignee: Sony Corp
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Filing: 1996-01-24
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Granted: 1998-01-20
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Expires: 2016-01-24
Abstract
Abstract A receiver apparatus comprises a first local oscillator, a first pair of mixer circuits, a second local oscillator, a second pair of mixer circuits, an adding circuit, a bandpass filter and a modulation circuit. When the frequency of a second local oscillating circuit varies, a center frequency of the bandpass filter also varies in the same way so as to eliminate tracking errors. A large portion of a circuit for a double superheterodyne receiver can thus be incorporated in a single IC chip, the receiver may be made simpler, and cheaper, and differences in the absolute values of the capacitors and resistors due to variation in manufacturing processes can be eliminated.
Inventors
- 👤 Taiwa Okanobu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:45
CPC Classifications
H; H03; H03D; H03D7/00; H03D7/16; H03D7/165; H03D7/166; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/26; H03J; H03J7/00; H03J7/02; H03J7/04; H04B1/28; H04B1/30
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
207 words
A receiver apparatus comprising: first local oscillating means for generating a pair of first locally oscillated signals out of phase with each other by ninety degrees; a first pair of mixer circuits for mixing a received signal having a high frequency with said pair of first locally oscillated signals to produce a pair of first intermediate frequency signals having a relatively low frequency; second local oscillating means for generating a pair of second locally oscillated signals out of phase with each other by ninety degrees; a second pair of mixer circuits for mixing said pair of first intermediate frequency signals with said pair of second locally oscillated signals, respectively, to produce a pair of second intermediate frequency signals having a predetermined frequency; an adding circuit for adding said pair of second intermediate frequency signals to each other; a bandpass filter for receiving an output signal from said adding circuit; and a demodulation circuit for reproducing an original received signal from the output of said bandpass filter, wherein said second local oscillating means comprises a capacitor and a resistor connected to determine a second locally oscillated intermediate frequency and said bandpass filter comprises a capacitor and a resistor connected to determine a center frequency of said bandpass filter.
Claim 2
Dependent Claim
207 words
A receiver apparatus comprising: first local oscillating means for generating a pair of first locally oscillated signals out of phase with each other by ninety degrees; a first pair of mixer circuits for mixing a received signal having a high frequency with said pair of first locally oscillated signals to produce a pair of first intermediate frequency signals having a relatively low frequency; second local oscillating means for generating a pair of second locally oscillated signals out of phase with each other by ninety degrees; a second pair of mixer circuits for mixing said pair of first intermediate frequency signals with said pair of second locally oscillated signals, respectively, to produce a pair of second intermediate frequency signals having a predetermined frequency; an adding circuit for adding said pair of second intermediate frequency signals to each other; a bandpass filter for receiving an output signal from said adding circuit; and a demodulation circuit for reproducing an original received signal from the output of said bandpass filter, wherein said second local oscillating means comprises a capacitor and a resistor connected to determine a second locally oscillated intermediate frequency and said bandpass filter comprises a capacitor and a resistor connected to determine a center frequency of said bandpass filter.
Claim 3
Dependent Claim
33 words
A receiver apparatus according to claim 1 wherein said demodulating circuit is an FM demodulating circuit and comprises a capacitor and a resistor connected to determine a center frequency of said demodulating circuit.
Claim 4
Dependent Claim
37 words
A receiver apparatus according to claim 1 comprising a single IC chip incorporating said capacitor and resistor determining said second locally oscillated intermediate frequency and said capacitor and resistor determining said center frequency of said bandpass filter.
Claim 5
Dependent Claim
49 words
A receiver apparatus according to claim 2 comprising a single IC chip incorporating said capacitor and resistor determining said second locally oscillated intermediate frequency, said capacitor and resistor determining said center frequency of said bandpass filter, and said capacitor and resistor determining said center frequency of said demodulating circuit.
Claim 6
Dependent Claim
31 words
A receiver apparatus according to claim 3 wherein change in the frequency of the received signal is carried out in accordance with a frequency change of said first locally oscillated signals.
Claim 7
Dependent Claim
31 words
A receiver apparatus according to claim 4 wherein change in the frequency of the received signal is carried out in accordance with a frequency change of said first locally oscillated signals.
Claim 8
Dependent Claim
31 words
A receiver apparatus according to claim 5 wherein said first local oscillating means comprises a phase-locked loop, further comprising an auto-frequency control circuit for auto-frequency controlling said second locally oscillated signals.
Claim 9
Dependent Claim
31 words
A receiver apparatus according to claim 6 wherein the first local oscillating means comprises a phase-locked loop, further comprising an auto-frequency control circuit for auto-frequency controlling said second locally oscillated signals.
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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) | 2001-01-19 | 2001-07-21 | 2002-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-01-19 | 2005-07-21 | 2006-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-01-19 | 2009-07-21 | 2010-01-20 | $7700.00 | Window Closed / Lapsed |