15GHz!!

 The SynthHD is a state of the art Dual Channel #RF Signal Generator. These devices have set the bar on microwave radio frequency generators for quality, size and price - designed and manufactured in the USA! Tune any frequency between 10MHz and 15GHz in 0.1Hz resolution. Adjust calibrated amplitude in 0.1dB resolution up to +20dBm and across more than 50dB of range. Each channels has independent frequency and amplitude settings, or set both channels to the same frequency and adjust phase between the two in 0.1 degree increments.

Expect excellent performance and high reliability despite the SynthHD Pro’s low cost https://www.saelig.com/windfreak/synthhd-v2.htm