| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent display of a spectrum waveform caused by fractional spurious components and allow quick measurements. <P>SOLUTION: When a width value of a predetermined span (analysis-object frequency range) is higher than a boundary value, a reference signal frequency is set to a predetermined reference value, a loop filter band narrower than an RBW (resolution bandwidth) is selected, thereby the fractional spurious within the RBW to prevent the fractional spurious is kept from being displayed as a spectrum waveform. When the width value of the predetermined span is smaller than the boundary value, the reference signal frequency is shifted from the reference value by a predetermined value; the frequency deference between a main signal component of a VCO output signal and the fractional spurious components is enlarged by an amount equal to a product of the shift amount and an integer part of a frequency division ratio; and the loop filter band is set within a range narrower than the enlarged frequency difference according to an RBW contained range to inhibit a level of the fractional spurious. <P>COPYRIGHT: (C)2011,JPO&INPIT |
