Keywords:Instruments, Plasma wave
Plasma waves are the important observation target for scientific missions investigating space plasma phenomena, and many scientific satellites observe plasma waves using onboard plasma wave instruments. Plasma wave receivers are composed of electromagnetic sensors and a plasma wave receiver which processes signals picked up by sensors. The plasma wave receiver requires high-performance electronic circuits, and it causes an increase in mass and volume. On the other hand, the miniaturization of observation instruments is highly demanded. Part of its reasons is the expanding usage of microsatellites and the increasing onboard instruments of satellites. To resolve this problem, we use the Application-Specific Integrated Circuits (ASIC) technology which enables to miniaturize electronic circuits. We already realized miniaturized waveform and spectrum types of plasma wave receiver by developing ASIC; however, frequency coverages of the developed receivers are up to 100 kHz, and wideband receiver is required.
In this study, we improve analog ASIC to become wideband. In previous analog ASIC, upper limit of the frequency coverage is determined by the frequency coverage of the anti-aliasing filter. The anti-aliasing filter is realized by using switched capacitor filter, and it requires high frequency clock signal. Thus, the operational amplifiers which compose switched capacitor filter requires wider frequency coverage then the receiver’s frequency coverage, and it is the biggest issue in broadening the previous ASIC. In this study, we develop the operational amplifier specialized for switched capacitor filter. In the presentation, we describe detailed design of the developed operational amplifier and switched capacitor filter.