Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
309 words
In a channel selector for a television receiver including a radio frequency section and an intermediate frequency section, the combination comprising: spectrum filter means disposed in the radio frequency section for receiving radio frequency signals representative of a plurality of television channels and for filtering at least one frequency spectrum of television channels from the received signals; at least one mixing means connected to the output of said spectrum filter means, said mixing means including a metal semiconductor field effect transistor and having first and second inputs coupled to simultaneously receive said frequency spectrum of television channels from said spectrum filter means and mixing signals of a selected intermediate frequency for frequency shifting the selected frequency channel of said frequency spectrum of television channels to a high intermediate frequency substantially greater than 45 MHZ; channel selecting filter means having an input coupled to the output of said mixing means for filtering said selected frequency channel at said high intermediate frequency so as to pass said selected frequency channel; second mixing means disposed in the intermediate frequency section and having first and second inputs coupled to simultaneously receive the filtered selected frequency channel at said high intermediate frequency from the output of said channel selecting filter means and mixing signals of a predetermined fixed frequency for frequency shifting said filtered selected frequency channel at said high intermediate frequency to a substantially lower second intermediate frequency; and amplifier means having a relatively high gain disposed in said intermediate frequency section and connected to the output of said second mixing means for providing gain to said filtered selected frequency channel at the lower second intermediate frequency, the added gain provided by said amplifier means in said intermediate frequency section being substantially in excess of the total gain provided to the signal in the radio frequency section through said channel selecting filter means.
Claim 2
Dependent Claim
309 words
In a channel selector for a television receiver including a radio frequency section and an intermediate frequency section, the combination comprising: spectrum filter means disposed in the radio frequency section for receiving radio frequency signals representative of a plurality of television channels and for filtering at least one frequency spectrum of television channels from the received signals; at least one mixing means connected to the output of said spectrum filter means, said mixing means including a metal semiconductor field effect transistor and having first and second inputs coupled to simultaneously receive said frequency spectrum of television channels from said spectrum filter means and mixing signals of a selected intermediate frequency for frequency shifting the selected frequency channel of said frequency spectrum of television channels to a high intermediate frequency substantially greater than 45 MHZ; channel selecting filter means having an input coupled to the output of said mixing means for filtering said selected frequency channel at said high intermediate frequency so as to pass said selected frequency channel; second mixing means disposed in the intermediate frequency section and having first and second inputs coupled to simultaneously receive the filtered selected frequency channel at said high intermediate frequency from the output of said channel selecting filter means and mixing signals of a predetermined fixed frequency for frequency shifting said filtered selected frequency channel at said high intermediate frequency to a substantially lower second intermediate frequency; and amplifier means having a relatively high gain disposed in said intermediate frequency section and connected to the output of said second mixing means for providing gain to said filtered selected frequency channel at the lower second intermediate frequency, the added gain provided by said amplifier means in said intermediate frequency section being substantially in excess of the total gain provided to the signal in the radio frequency section through said channel selecting filter means.
Claim 3
Dependent Claim
107 words
In a channel selector as set forth in claim 1, further including amplifier means having a relatively low gain disposed in said radio frequency section so as to be interposed between said spectrum filter means and said at least one mixing means, said amplifier means in said radio frequency section having an input coupled to said spectrum filter means for receiving said frequency spectrum of television channels from said spectrum filter means and an output coupled to the first input of said at least one mixing means for transmitting low gain amplified signals of said frequency spectrum of television channels to said at least one mixing means.
Claim 4
Dependent Claim
33 words
In a channel selector as set forth in claim 2, wherein the total gain provided to the signal in the radio frequency section by said amplifier means disposed therein is less than 10dB.
Claim 5
Dependent Claim
56 words
In a channel selector as set forth in claim 1, wherein said spectrum filter means comprises at least one fixed filter having at least one predetermined frequency passband for receiving radio frequency signals representative of a plurality of television channels and for filtering at least one fixed frequency spectrum of television channels from the received signals.
Claim 6
Dependent Claim
22 words
In a channel selector as set forth in claim 1, wherein said channel selecting filter means comprises acoustic surface wave filter means.
Claim 7
Dependent Claim
30 words
In a channel selector as set forth in claim 1, wherein the high intermediate frequency produced from said at least one mixing means is between 300 MHZ and 400 MHZ.
Claim 8
Dependent Claim
26 words
In a channel selector as set forth in claim 6, wherein the lower second intermediate frequency produced from said second mixing means is approximately 45 MHZ.
Claim 9
Dependent Claim
71 words
In a channel selector as set forth in claim 1, further including additional amplifier means connected between said channel selecting filter means and the first input of said second mixing means for providing gain to said filtered selected frequency channel passed by said channel selecting filter means prior to the introduction of said filtered selected frequency channel at the high intermediate frequency to the first input of said second mixing means.