Here is a small selection of possible replacement units.
RF Output Frequency: 14.0-14.5 GHz. Output Power @P1dB 1W (+30 dBm min) IF Frequency: 950-1450 GHz. Input Connector: Type F Female. Output Interface: WR75 Waveguide Flange (with Groove). Power Requirement: +24VDC (+15 to +24 VDC). Power Consumption: 18W max. Weight: 1 kg (2.2 lbs)