Distinction of the actual line and the image line in the frequency changer for the spectrum analyzer

摘要

This method distinguishes the image line and the actual line which occur from the frequency line of the input signal in the frequency converter. The above-mentioned frequency converter is output the filter assembly which the signal which is mixed the filter is done (6) has the mixer which mixes with the signal which is supplied the above-mentioned input signal and (2) and with the said mixer (2) by the local oscillator (4). At least one sweep is executed, with the said sweep frequency of the above-mentioned local oscillator changes, is recorded in regard to the frequency where the signal level in outputting the particular frequency converter is converted one group. Further sweep although frequency of the actual line which occurs with the input line at the time of the said further sweeping it becomes identical with the frequency of the actual line which occurs with the said input line the description above at least at the time of one sweeping in order the frequency where the line occurs the description above at least in each of one sweep not to agree, is executed also the frequency of the image line which occurs with each input line at the time of the said further sweeping. Selective figure Figure 2