FOUR-STAGE PHASE DISPLACEMENT MODULATOR, IN PARTICULAR FOR AMPLITUDE MODULATION WITH TWO QUADRATURE CARRIERS WITH A LARGE NUMBER OF STATES

摘要

P The modulator comprises a four-output RF signal generator Q5 to Q8 delivering the signal with four phases offset by 90degrees (s). A phase selector has four carrier inputs connected to the outputs Q5 to Q8, four modulating signal inputs and four out of phase carrier outputs. Each modulating signal input is connected to the control input of a switch 9 to 12 mounted between a carrier input and a phase-shifted carrier output. / P P The generator comprises a signal source Ho, Ho / in phase opposition and two frequency dividers 3 and 4 with two outputs Q3, Q3 / and Q4, Q4 / in phase opposition. It further comprises two pairs of flip-flops 5, 6 and 7, 8 whose outputs Q5, Q6, Q7 and Q8 form the four outputs of the generator. The signal inputs of the flip-flops 5 and 6 are connected to the outputs Q3 and Q3 / of the first divider and the signal inputs of the flip-flops 7 and 8 are connected to the outputs Q4 and Q4 / of the second divider. The out-of-phase carrier outputs are connected to the inputs of a gate or 13. Between the clock inputs of the latches and the ground are provided variable capacitors C1 to C4. / P P A modulator MAQ 2 ** 2 ** n includes n such modulators MDP4 whose outputs are connected to the inputs of n attenuators followed by a summator. / P