| 摘要 |
PROBLEM TO BE SOLVED: To provide a frequency converting circuit capable of widening the allowable level and allowable frequency range of oscillation signal, suppressing the distortion of the signal, outputting the local signal of less phase deviation and reducing the phase deviation at the time of frequency conversion. SOLUTION: A single differential converting circuit 10 converts an oscillation signal Sin to a pair of differential signals S01 and S02, limits the level through a limiter amplifier 20 and outputs differential signals SLO and SLOB having a fixed amplitude. A DC feedback circuit 40 reduces the DC offset of differential signals SLO and SLOB by negatively feeding the low frequency and DC components of differential signals SLO and SLOB back to the input side of the single differential converting circuit 10, a frequency divider 30 respectively divides the frequencies of differential signals SLO and SLOB and outputs local signals SLO1 and SLO2 composed of a pair of orthogonal signals, and mixers 50 and 60 respectively multiply the local signals and orthogonal input signals SM1 and SM2 and output converted signals SMO1 and SMO2.
|
