Patent attributes
A linear channel select filter for an Intermediate Frequency selector of a satellite broadcasting tuner, linearly changes a desired frequency by adjusting an output current, and includes: a transconductance (GM) current cell controller for determining a control voltage according to a select signal, generating the output current according to an differential input voltage, linearly controlling the output current according to the control voltage, and providing a linearly variable resistance according to the linearly controlled output current, and a capacitor circuit coupled to the GM cell controller to provide a capacitance to generate a cutoff frequency voltage according to the output current and the variable resistance. An occupying area and a size of the filter are reduced.
