Input circuit of satellite tuner
AssigneeSony Corporation
InventorNaohito Nakamura
Life of this patent
Estimating the term…
Abstract
A circuit that prevents a receiving signal from leaking to an LNB supply line to thereby deteriorate input VSWR characteristic includes a capacitor of about 1000 pF for removing noise and a capacitor of about 1 pF for passing a high frequency component which leaks to an LNB voltage supply line to the ground provided between the LNB voltage supply line and the ground. By the capacitor of about 1000 pF, a noise component included in the LNB voltage supply line is removed. Further, by the capacitor of about 1 pF, the high frequency signal component which leaks via a choke coil is bypassed to thereby reduce impedance of a node NA over a broad band and prevent a reflecting wave from being produced at the node NA and input VSWR from being deteriorated.
Claims15
An input circuit of a satellite tuner comprising:
- an antenna terminal for connecting to an outside converter via a cable;
- a high pass filter for extracting a high frequency signal component from the outside converter transmitted via the cable and for transmitting the extracted high frequency signal to an initial stage circuit;
- a power source supply line for connection to a power source for providing power for the outside converter via the cable:
- a choke coil connected between the power source supply line and the antenna terminal for blocking the high frequency signal component from the outside converter transmitted via the cable and transmitting the power from the power source supply line to the antenna terminal;
- a first capacitor connected between the power source supply line and ground for removing influence of a noise component included in the power transmitted by the power source supply line;
- and
- a second capacitor connected between the power source supply line and ground for removing influence of the high frequency signal component which leaks in via the choke coil,
- wherein a self-response frequency of the second capacitator is higher than a frequency of the high frequency signal inputted via the cable.
An input circuit of a satellite tuner comprising:
- an antenna terminal for connecting to an outside converter via a cable;
- a high pass filter for extracting a high frequency signal component from the outside converter transmitted via the cable and for transmitting the extracted high frequency signal to an initial stage circuit;
- a power source supply line for connection to a power source for providing power for the outside converter via the cable;
- a choke coil connected between the power source supply line and the antenna terminal for block in a the high frequency signal component from the outside converter transmitted via the cable and transmitting the power from the power source supply line to the antenna terminal;
- a first capacitor connected between the power source supply line and ground. for removing influence of a noise component included in the power transmitted by the power source supply line;
- and
- a second capacitor connected between the power source supply line and ground for removing influence of the high frequency signal component which leaks in via the choke coil,
- wherein a self-resonance frequency of the second capacitor is higher than a frequency of the high frequency signal inputted via the cable.
Dependencies are inferred from the claim text.