Hot electron bolometer receivers for Herschel and beyond
- H F Merkel
- Proc. SPIE
The Heterodyne Instrument for Far Infrared (HIFI) on ESA's Herschel Space Observatory utilizes a variety of novel RF components in its five SIS receiver channels covering 480-1250 GHz and two HEB receiver channels covering 1410-1910 GHz. The local oscillator unit will be passively cooled while the focal plane unit is cooled by superfluid helium and cold helium vapors. HIFI employs W-band GaAs amplifiers, InP HEMT low noise IF amplifiers, fixed tuned broadband planar diode multipliers, high power W-band Isolators, and novel material systems in the SIS mixers. The National Aeronautics and Space Administration through the Jet Propulsion Laboratory is managing the development of the highest frequency (1119-1250 GHz) SIS mixers, the local oscillators for the three highest frequency receivers as well as W-band power amplifiers, high power W-band isolators, varactor diode devices for all high frequency multipliers and InP HEMT components for all the receiver channels intermediate frequency amplifiers. The NASA developed components represent a significant advancement in the available performance. This paper presents an update of the performance and the current state of development. 1. INTRODICTION A fully modern heterodyne receiver designed for autonomous operations, such as the Heterodyne Instrument for Far Infrared (HIFI) 1 scheduled for launch on the European Space Agency's Herschel Space Observatory, requires a number of technological improvements for implementation. In HIFI, the NASA funded " High Frequency Subsystem " has played a major role in developing and providing enabling technology for this demanding flight application. The fundamental HIFI instrument application is an observatory with unparalleled capability and flexibility. The requirements include nearly complete frequency coverage from 480 to 1910 GHz. This paper updates a previous paper 2 in the performance and the current state of development. In many cases, the final flight hardware has been flight qualified, built and accepted. Two other papers in this conference deal with local oscillators 3 and 1.2 THz SIS mixers 4 in more detail. A final paper 5 in this conference discusses the overall HIFI local oscillator subsystem architecture and development.