| 摘要 |
<P>PROBLEM TO BE SOLVED: To simplify a constitution of a folding circuit for self-diagnosing an RF unit or the like in a radio communication apparatus. <P>SOLUTION: A control circuit 50 sets a local signal oscillator 18 to a turned-on state (oscillation state), and supplies a transmission signal Sd for test having a predetermined amplitude, of 1.6 [GHz] from a frequency converter 52 to a power amplifier 10. A leakage signal Se of the signal Sd from a diplexer 12 and a local signal L having 0.1 [GHz] are supplied to a low-noise amplifier 20. A signal having the same frequency (1.5 GHz) as a received signal is taken out by a band-pass filter 58 from a cross modulation signal Sm of an output signal of the amplifier 20 becoming nonlinear at a low level. The control circuit 50 can self-diagnose the RF unit 54 or the like according to this taken-out signal. <P>COPYRIGHT: (C)2003,JPO |
