Hello Venkateshkuma,

First, be sure to put your ZQ520 printer into ZPL mode.
This can be done programmatically by sending the following command to the printer:

! U1 setvar “device.languages” “zpl”

You would then need to convert the PDF into a black and white PNG file.
I’m not sure if you can do this natively in the Windows phone environment, you may need to use a third-party library or SDK.

Then convert your PNG File and convert it to either Hexadecimal or binary data and wrap it in ~DY ZPL command.
More information on the  ~DY command can be found in the ZPL Programming Guide:
https://www.zebra.com/content/dam/zebra/manuals/en-us/software/zpl-zbi2…

Hope this helps.

Greg