A cryogenic solid state LO source at 1.9THz

Abstract

The Low Frequency Array instrument at SOFIA is a heterodyne array designed to observe in the complete range between 1.9 and 2.5 THz. It is a 14 pixel instrument, working in a dual polarization configuration. To provide enough LO power for the 14 HEB mixers a cryogenic solid state LO source is used. It consists of two identical set of millimeter wave amplification and multiplication chains, one per polarization. The frequency coverage is limited to 1.830 to 2.070 GHz, centered on one of the main scientific target of the instrument, the CII at 158mm. We present an overview of the design of this LO source and present the experimental results obtained.