Tunable high frequency input circuit for a television receiver that tunes both VHF and UHF channels and can be readily integrated
AssigneeU.S. Philips Corporation
InventorsKlaus Lohn, Georg Lutteke, Gerd Schiefer, Lammert Bruntink, Paulus Petrus Maria Groenewegen, Hans Viktor Weinerth, Wilhelmus Antonius Joseph Marie Zwijsen, Karel Petrus Van Rooij
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Abstract
The IC television tuner has a tunable oscillator and a fixed oscillator, two mixer stages and a filter in between. This tuner operates at two intermediate frequencies the first of which lies in the GHz range. The two oscillators are coupled through hybrid rings.
Claims20
A circuit arrangement for tuning both VHF and UHF television signals between upper and lower frequency limits, said circuit comprising a first mixer stage having a first input means for receiving said television signals, a second input, and an output means for providing a signal at a first intermediate frequency which is higher than twice said upper frequency limit;
- a first oscillator coupled to said second input and tunable in a range below said first intermediate frequency;
- a gyromagnetic filter tuned to said first intermediate frequency and having an input coupled to said first mixer output and an output;
- a second mixer stage having a first input coupled to said filter output, a second input, and an output means for providing a signal at a second intermediate frequency lower than said lower frequency limit;
- and a second oscillator coupled to said second mixer second input and fixed tuned to a frequency above said first intermediate frequency.
A circuit arrangement for tuning both VHF and UHF television signals between upper and lower frequency limits, said circuit comprising a first mixer stage having a first input means for receiving said television signals, a second input, and an output means for providing a signal at a first intermediate frequency which is higher than said upper frequency limit;
- a first oscillator coupled to said second input;
- a gyromagnetic filter tuned to said first intermediate frequency and having an input coupled to said first mixer output and an output;
- a second mixer stage having a first input coupled to said filter output, a second input, and an output means for providing a signal at a second intermediate frequency lower than said lower frequency limit;
- and a second oscillator coupled to said second mixer second input, at least one of said mixers comprising a diode ring having eight diodes, each leg having two series coupled diodes with equal polarity.
Dependencies are inferred from the claim text.