| 摘要 |
PURPOSE:To allow a spectrum analyzer and a network analyzer to share a common circuit constitution part, by setting the level distribution of the whole system to the best level according to an in-use mode. CONSTITUTION:For use as a spectrum analyzer, when a signal having logic H is supplied to a switching terminal 32, AND gates 29-1-29-6 are opened and mixers 16, 19 and 22 and intermediate frequency amplifiers 18, 21 and 24 in respective stages are set to the best levels held in a spectrum analyzer level holding part 26. When the signal having logic H is applied to a terminal 33, the mixers and intermediate frequency amplifiers in the respective stages are set to respective levels suitable for a network analyzer by a network analyzer level holding part 27. Consequently, the functions of the spectrum analyzer reduce higher harmonic distortion and cross modulation distortion, and those of the network analyzer secure the linearity of input and output characteristics. |
