We have designed DDS based board using IC AD9914. The application is to generate frequency range of 0.5-18 GHz.DDS board is generating frequencies from 0.4-1.6 GHz. There after doubling, amplification and switching is carried on to generate the final band of frequencies. there are 2 main problems am facing,
1) the IC AD9914 is getting heated very fast.
2) The unwanted spurious is very much high at the output of the DDS. As the chain up consists of amplifiers this is becoming still more worse.
3) We see sudden rise of noise floor and spurious and subsides immediately leaving the spurious level high.
Am attaching both the pics
The behaviour of the IC is intermittant
Please suggest and find the attachment.