Process and device for modulating a carrier with amplitude and phase error compensation

摘要

The invention relates to processes and devices which make it possible to directly modulate an RF carrier with a quadrature signal. It consists in filtering ( 504 ) this quadrature signal around zero so as to introduce alternately ( 507, 508 ) on each of the channels a low-frequency subcarrier that will serve as reference. Each of these channels is alternately demodulated in a synchronous manner ( 519 ) cosine-wise and sine-wise. The demodulation signal is filtered ( 523 ) so as to recover the subcarrier marred by modulation errors. The measurement of these errors ( 524 ) allows feedback correction ( 503 ) of the quadrature signal. It makes it possible to perform the major part of the operations in the digital processor ( 501 ) and enables direct vector modulation to be made possible at millimeter frequencies.