| 摘要 |
<p>In a frequency translator for r-f television signals and the like there is provided an input frequency selective matching network to pass only r-f television signals in a predetermined range of about 50 to 300 MHz (vhf), a novel combination oscillator, impedance matching network, and mixer arranged for mixing incoming television signals from a cable or antenna with a preselected reference signal of a constant frequency generated by the oscillator to produce output signals from the mixer in a higher band of frequencies of about 500 to 750 MHz (uhf). An output frequency selective matching network passes only signals in said second band of frequencies to an output terminal. The impedance matching network provides a conjugate match for the output impedance of the oscillator and the input impedance of the mixer so as to inhibit the reflection of undesirable signal products from the mixer back to the oscillator and minimize power loss. The output frequency selective network and mixer arrangement do not require an active gain stage and an associated additional frequency selective matching networks in an input circuit ahead of the mixer.</p> |
