Direct modulation in PLL without up conversion mixer

[wireless man]

What system is feasible in implementing direct modulation in PLL without up conversion mixer?
GMSK? QPSK? or others?
Thanks

 

[RFCMOS]

Hello,

You could use translational PLL for constant envelope modulation like GMSK and QPSK

 

[khouly]

yeah i agree with RFCMOS , PLL can only modulate the phase and frequency ,

but others like QAM and so on , no

Khouly

 

[bingdao89]

i think the two below is right!