Two 1.7 to 1.9 THz frequency multiplier LO chains for integration into the Heterodyne Instrument for the Far-Infrared (HIFI) on the Herschel Space Observatory.

Local Oscillators are an essential part of heterodyne receivers, which are commonly used in submillimeter-wave or far-IR high-resolution spectrometers. The use of "multiplier" techniques that include JPL-developed doublers and triplers have resulted in development of very stable LO's at high frequencies (e.g., 2 THz). New developments in LO capability have enabled several space flight instruments (MLS, MIRO, Herschel HIFI) and are critical components in new heterodyne spectrometers for planetary science applications. Future instrument concepts will include heterodyne array receivers, which will require higher LO output power levels at frequencies ranging up to several THz in order to achieve optimum receiver performance for each element of the array.