US5034994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single balanced mixer with output filter
Assignee: RCA Licensing Corp
•
Filing: 1989-04-13
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Granted: 1991-07-23
•
Expires: 2009-04-13
Abstract
Abstract A balanced mixer and output filter for television receivers and the like is presented. The mixer is followed by a fairly selective bandpass filter to protect the IF amplifiers from first and second adjacent channel signals.
Inventors
- 👤 Max W. Muterspaugh
- 👤 William D. Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 00:28
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/44; H03; H03D; H03D7/00; H03D7/02; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/26
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
149 words
In a television receiver, apparatus comprising: an RF stage for supplying an RF signal corresponding to a selected channel and undesirably capable of supplying an RF signal corresponding to at least a portion of one channel adjacent to said selected channel; a local oscillator for generating a local oscillator signal; a passive mixer for combining said selected RF signal and said local oscillator signal to provide an IF signal; a bandpass filter coupled to said passive mixer without any intervening device capable of mixing or amplifying, said bandpass filter including at least a doubly turned section for filtering the output signal of said passive mixer; an amplifier coupled to said first bandpass filter for amplifying the output signal of said first bandpass filter; and a television IF filter coupled to said amplifier for filtering the output signal of said amplifier to produce a filtered IF signal suitable for demodulation.
Claim 2
Dependent Claim
149 words
In a television receiver, apparatus comprising: an RF stage for supplying an RF signal corresponding to a selected channel and undesirably capable of supplying an RF signal corresponding to at least a portion of one channel adjacent to said selected channel; a local oscillator for generating a local oscillator signal; a passive mixer for combining said selected RF signal and said local oscillator signal to provide an IF signal; a bandpass filter coupled to said passive mixer without any intervening device capable of mixing or amplifying, said bandpass filter including at least a doubly turned section for filtering the output signal of said passive mixer; an amplifier coupled to said first bandpass filter for amplifying the output signal of said first bandpass filter; and a television IF filter coupled to said amplifier for filtering the output signal of said amplifier to produce a filtered IF signal suitable for demodulation.
Claim 3
Dependent Claim
14 words
The apparatus of claim 1 wherein the last mixer is a single balanced mixer.
Claim 4
Dependent Claim
24 words
The apparatus of claim 2 further comprising a RF amplifier for amplifying the RF signals and feeding the amplified RF signals to the mixer.
Claim 5
Dependent Claim
15 words
The apparatus of claim 1 wherein the bandpass filter is configured as a Butterworth filter.
Claim 6
Dependent Claim
16 words
The apparatus of claim 1 wherein the television IF filter comprises a surface acoustic wave filter.
Claim 7
Dependent Claim
150 words
In a television receiver, apparatus comprising: an RF stage for supplying an RF signal corresponding to a selected channel and undesirably capable of supplying an RF signal corresponding to at least a portion of one channel adjacent to said selected channel; a local oscillator for generating a local oscillator signal; a balanced passive mixer for combining said selected RF signal and said local oscillator signal to provide an IF signal; a bandpass filter coupled to said passive mixer without any intervening device capable of mixing or amplifying, said bandpass filter including at least a doubly tuned section for filtering the output signal of said passive mixer; an amplifier coupled to said first bandpass filter for amplifying the output signal of said first bandpass filter; and a television IF filter coupled to said amplifier for filtering the output signal of said amplifier to produce a filtered IF signal suitable for demodulation.
Claim 8
Dependent Claim
150 words
In a television receiver, apparatus comprising: an RF stage for supplying an RF signal corresponding to a selected channel and undesirably capable of supplying an RF signal corresponding to at least a portion of one channel adjacent to said selected channel; a local oscillator for generating a local oscillator signal; a balanced passive mixer for combining said selected RF signal and said local oscillator signal to provide an IF signal; a bandpass filter coupled to said passive mixer without any intervening device capable of mixing or amplifying, said bandpass filter including at least a doubly tuned section for filtering the output signal of said passive mixer; an amplifier coupled to said first bandpass filter for amplifying the output signal of said first bandpass filter; and a television IF filter coupled to said amplifier for filtering the output signal of said amplifier to produce a filtered IF signal suitable for demodulation.
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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) | 1994-07-22 | 1995-01-21 | 1995-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-22 | 1999-01-21 | 1999-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-22 | 2003-01-21 | 2003-07-23 | $7700.00 | Window Closed / Lapsed |