Patent ID: 8154659

Claim:
A mobile communication terminal comprising: a transmission/reception circuit having a mobile phone function; a communication unit having a function of communicating with a network formed by at least one local area network communication unit and/or at least one personal area network communication unit, the at least one local area network communication unit and/or the at least one personal area network communication unit using a frequency band in an industry-science-medical (ISM) band; and a digital terrestrial television broadcasting receiver to receive digital terrestrial television broadcasting targeted to mobile communication terminals, wherein the digital terrestrial television broadcasting receiver includes: a low-noise amplifier to amplify a received and inputted RF signal; a local oscillator to generate a signal having a frequency corresponding to an output signal of the low-noise amplifier; a mixer to mix the output signal of the low-noise amplifier with the output signal of the local oscillator; an A/D converter to convert a baseband signal contained in the RF signal into a digital signal, the baseband signal being obtained due to the mixture; and a demodulation circuit to modulate the digital signal obtained by the A/D converter, and the mobile communication terminal having a self-diagnosis mode configured to receive a first transmission signal outputted by the transmission/reception circuit having a mobile phone function and a second transmission signal outputted by the communication unit having a function of communicating with a network, using the digital terrestrial television broadcasting receiver; to generate a difference signal having a frequency that is a difference between both the transmission signals by mixing both the transmission signals using a non-linear characteristic of the low-noise amplifier; and to self-diagnose whether the digital terrestrial television broadcasting receiver is normally operating, on the basis of an output of the A/D converter based on an output signal of the mixer obtained by mixing the difference signal with the output signal of the local oscillator.