ISSN:
1089-7623
Quelle:
AIP Digital Archive
Thema:
Physik
,
Elektrotechnik, Elektronik, Nachrichtentechnik
Notizen:
For research into space plasma turbulence, we have developed a number of space-flight instruments for making in situ measurements of plasma wave activity. One of these instruments, the NRL downconverter, is used to measure plasma waves in the 2- to 20-MHz frequency range by downconverting a 100-kHz band of frequencies to the baseband. Input frequency tuning is controlled by an imbedded microcomputer, and can be programmed to scan in any desired frequency pattern. The in-phase and quadrature receiver outputs, each having a 50-kHz bandwidth, are processed externally by digital signal processors (DSP). The receiver achieves 35 dB of sideband rejection using a hybrid quadrature mixer design, which incorporates an analog front end with digital signal processing. This design yields 15 dB of improved sideband rejection over more conventional analog techniques. The microcomputer control, DSP processing, and modular design contribute to the flexibility of the receiver, which has allowed the system to be used on a number of different missions. © 1995 American Institute of Physics.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.1146045
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