Kinda! I want to make sure NOT to jam or degrade any of the UMTS band, except while stopping something connecting to a certain cell by jamming the downlink frequency it close range (within a few metres). Just a manually tunable fixed frequency narrowband signal would probably do, I'm just not sure how feasible that is. Basically this principle/method works fine using a Rohde and Schwarz 20 GHz sig gen I have here, giving 15 dBm into a poorly tuned antenna. I can't have this here and use an expensive bit of test gear we need for other stuff, just for this though.If I can make an oscillator that doesn't drift much and stays at 2122.4 MHz without varying out of it's 5 MHz channel bandwidth, then the simpler the better to be honest! All RF chips of this frequency seem to involve a certain amount of complexity and control for synthesis that I've found.