Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

use PLL as n-PSK modulator?

Status
Not open for further replies.
F

fenfei

Member level 1
Joined
Apr 19, 2010
Messages
38
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
1,559
using pll as FSK modulator is easy to understand.how to use a PLL as PSK modulator? Anyone have suggestion?
I have read some article about using PLL as GMSK modulator by dlta-sigma modulator. changing the divider N could chang the frequency,but how could the N divider affect phase of VCO output?
 

You can't use just one PLL for making a PSK modulator.
There is a possibility to use two synchronized PLL's (working as phase/frequency modulators) with summed outputs, and a phase shifter.
 

you could also combine a PLL with a DDS chip, where the DDS either sums in a phase shift via a mixer before the divider, or the DDS is the PLL clock, and you modulate (in small steps) the clock. These only work for low data rates due to PLL settling time.
 

biff44 said:
you could also combine a PLL with a DDS chip, where the DDS either sums in a phase shift via a mixer before the divider, or the DDS is the PLL clock, and you modulate (in small steps) the clock. These only work for low data rates due to PLL settling time.
Click to expand...

do you mean that the data rate must be lower than loop bandwidth?
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top