AD9954 harmonices use

[7rots51]

I want to have a FSK signal at 1500MHZ,I want to modulate AD9954(crystal 20MHZ ,PLL*20) at 100MHZ.

The DDS have a 1500MHZ spur at -40dBc relative ro main 100MHZ signal,
I want to filter out other spur signals and extract 1500MHZ and amplify it to 0dbm.

Is this a right way for FSK? What filter should I use and is better to remove spurs?

 

[FvM]

I don't think that you are following a promising technique for a FSK transmitter. A lot of synthesizer circuits is able to generate 1500 Mhz or at least 500 or 750 MHz directly. This way, you can get a spurious free 1500 MHz carrier with less effort.

 

[7rots51]

A lot of synthesizer circuits is able to generate 1500

Please give some part numbers.

 

[FvM]

E.g. Analog ADF4360 With frequency doubling or tripling, nearly any ISM FSK transmitter as CC1050 can be used.