Signal-to-noise generators come in multiple bands

WIRELESS TELECOM GROUP CNG-EbNo series of precision signal-to-noise generators are designed for Carrier-to-Noise (C/N), Carrier-to-Noise density (C/No), Signal-to-Noise (S/N), Carrier-to-Interferer (C/I) and Bit Energy-to-Noise density (Eb/No) analysis. Products come in a variety of off-the-shelf frequency bands, as well as customized frequency bands. Unit is available in 50 or 75 ohms impedance versions, with a signal input range is -55 dBm to +5dBm. Nominal gain for the carrier path is +/-1.0dB with a gain resolution of 0.1dB, and flatness from +/- 0.2 dB.

http://www.wtcom.com