ADF4350

ADF4350 is PLL-based signal generator capable if generating sine wave from 137 MHz to 4.4 GHz.

ADF4350 cicuit

You can be solderered evaluation board with ADF4350 on ebay or aliexpress for around $20 USD.

ADF4350

ADF4350 can be programmed with Arduino. Examples are freely available.

1. The first gives code to write proper registers
2. The second example provides a code with conversion from frequency into a register