ANALOGUE MODULATION METHOD AND MONOLITHIC INTEGRATED CIRCUIT WITH MIXER STAGE COMPRISING NON-POLARISED FIELD-EFFECT TRANSISTORS

摘要

The invention concerns a method and a circuit for analogue phase and/or amplitude modulation of a high frequency carrier signal with an Î or Q low frequency analogue modulation signal, comprising at a least mixer stage (5, 6) including two field-effect transistor, called modulation transistors (21, 22), mounted with the sources (23, 24) jointly connected to ground, and whereof the drains (25, 26) are not polarised. The method consists in applying on the gates (30, 31) of the modulation transistors (21, 22) I or Q modulating analog electric signals, I or Q at low frequency matching each other, whereof the amplitude is less than a maximum value Amax beyond which the power of the signal modulated in output is no longer proportional to the power of the modulating signal.