| 摘要 |
PURPOSE: A circuit for generating a signal to check a receiving path in a mobile terminal is provided to generate a signal to check a receiving path in a mobile terminal and to offer a circuit to check the receiving path using a cheap low frequency signal generator. CONSTITUTION: An Rx local signal, generated from a local oscillator(155) is inputted to an AGC(Automatic Gain Control)(210) that maintains the signal at a uniform local signal level. Then the signal is separately inputted to a transmitting modulator(140) and a mixer(203) by a splitter(205). The mixer(203) mixes the signal transferred from the splitter(205) with a signal of 800MHz generated from a low frequency signal generator(201), and transfers the mixed signal to a switch(SW1). At this moment, only an Rx frequency signal in the mixed signal is selectively filtered and supplied to a receiving path through the switch(SW1). In the case of checking the abnormality of the receiving path, the switch(SW1) switches the mixed signal to the receiving path.
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