I am building a generator scanning 5 frequency ranges and each range has its own frequency step, the total frequency range is 90KHz to 1GHz, the amplitude is fixed (60udB) the pulse width is not important.Welcome to AAC!
How accurately does the pulse shape need to conform to the true Dirac function?
What limits are there on pulse amplitude and width?
Have you read this guide, and the relevant datasheet, for that IC?