NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Microwave Radiometers from 0.6 to 22 GHz for Juno, a Polar Orbiter around JupiterA compact radiometer instrument is under development at JPL for Juno, the next NASA New Frontiers mission, scheduled to launch in 2011. This instrument is called the MWR (MicroWave Radiometer), and its purpose is to measure the thermal emission from Jupiter's atmosphere at selected frequencies from 0.6 to 22 GHz. The objective is to measure the distributions and abundances of water and ammonia in Jupiter's atmosphere, with the goal of understanding the previously unobserved dynamics of the subcloud atmosphere, and to discriminate among models for planetary formation in our solar system. The MWR instrument is currently being developed to address these science questions for the Juno mission. As part of a deep space mission aboard a solar-powered spacecraft, MWR is designed to be compact, lightweight, and low power. The entire MWR instrument consists of six individual radiometer channels with approximately 4% bandwidth at 0.6, 1.25,2.6,5.2, 10,22 GHz operating in direct detection mode. Each radiometer channel has up to 80 dB of gain with a noise figure of several dB. The highest frequency channel uses a corrugated feedhorn and waveguide transmission lines, whereas all other channels use highly phase stable coaxial cables and either patch array or waveguide slot array antennas. Slot waveguide array antennas were chosen for the low loss at the next three highest frequencies and patch array antennas were implemented due to the mass constraint at the two lowest frequencies. The six radiometer channels receive their voltage supplies and control lines from an electronics unit that also provides the instrument communication interface to the Juno spacecraft. For calibration purposes each receiver has integrated noise diodes, a Dicke switch, and temperature sensors near each component that contributes to the noise figure. In addition, multiple sensors will be placed along the RF transmission lines and the antennas in order to measure temperature gradients. All antennas and RF transmission lines must withstand low temperatures and the harsh radiation environment surrounding Jupiter; the receivers and control electronics are protected by a radiation-shielding enclosure on the Juno spacecraft that also provides for a benign and stable operating temperature environment. This paper will focus on the concept of the MWR instrument and will present results of one breadboard receiver channel.
Document ID
20090026409
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
P. Pingree
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Janssen, M.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Oswald, J.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Brown, S.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Chen, J.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Hurst, K.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Kitiyakara, A.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Maiwald, F.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Smith, S.
(MMW Technology, Inc. Lawndale, CA, United States)
Date Acquired
August 24, 2013
Publication Date
March 1, 2008
Subject Category
Spacecraft Instrumentation And Astrionics
Meeting Information
Meeting: IEEE Aerospace Conference
Location: Big Sky, MT
Country: United States
Start Date: March 1, 2008
End Date: March 8, 2008
Sponsors: Institute of Electrical and Electronics Engineers
Distribution Limits
Public
Copyright
Other
Keywords
receiver
antenna
radiometer
electronics
microwave

Available Downloads

There are no available downloads for this record.
No Preview Available