Patent ID: 6594477
Filing Date: 2003-07-15
Classification: H03D,H03J,H04B

Abstract:
An electronic tuner comprising:an up-converter for converting an input high frequency signal into a first intermediate frequency signal of a frequency higher than the high frequency signal; a down-converter for converting the first intermediate frequency signal into a second intermediate frequency signal of a frequency lower than the high frequency signal; a high frequency amplifying circuit, disposed on a signal transmission path between an input of the high frequency signal and an output of the second intermediate frequency signal as an output signal, for amplifying an input signal; and a temperature compensating section for compensating for deterioration of electrical characteristics caused by a change in temperature, a filter circuit, disposed on the signal transmission path between an input of the high frequency signal and an output of the second intermediate frequency signal as an output signal, wherein the high frequency amplifying circuit includes a field-effect transistor as an amplifying element, and the temperature compensating section includes: a thermistor that is disposed in a preceding stage or succeeding stage of the filter circuit and has such a characteristic that resistance is decreased in substantially proportion to a rise in temperature within a predetermined temperature range; and a serial circuit composed of the thermistor and a coupling capacitor of the filter circuit.