The 95 GHz Gunn Diode Microwave Source

The 95 GHz microwave source consisting of (from the left to right):

• Gunn diode oscillator
• Isolator preventing reflected microwaves from entering the oscillator
• Mixer used to lock the microwave frequency
• Attenuator (large black box)
• Frequency multiplier generating higher harmonics of the base frequency 95 GHz
• High-pass filter (in this picture the X3 filter is attached, cutting off frequencies 95 and 190 GHz while passing 285 GHz and to some extent, higher harmonics)
• Horn (the waveguide is seen to the right of the horn)

The 95 GHz source is used only with the transmission spectrometer. The 110 GHz microwave generator that is used with either the transmission or with quasi-optical instrument contains similar components.