METHOD AND SYSTEM FOR ADJUSTING SPURIOUS LINES OF AN OUTPUT FREQUENCY SPECTRUM IN A SIDEBAND FREQUENCY TRANSLATING DEVICE

摘要

The invention concerns a method which consists in: delivering in input on two channels of the frequency translating device two parameterable and mutually phase-shifted test signals TXI and TXQ; measuring the level of each of the spurious lines for different test values of different parameters; and determining the reference values for the different parameters for minimising the levels of spurious lines, by digital computation carried out from a predetermined number of different test values and corresponding measured level values, taking into account two parabolic relationships relating the levels of two spurious lines to said parameters. Thus, the adjusting time interval is reduced to a minimum by using a reduced number of test values. The invention is applicable to mobile telephone system.