One-chip analog circuits for a new type of plasma wave receiver on board space missions

Takahiro Zushi,Hiroshi Yamakawa,Hirotsugu Kojima

doi:10.5194/gi-6-159-2017

Abstract

Abstract. Plasma waves are important observational targets for scientific missions investigating space plasma phenomena. Conventional fast Fourier transform (FFT)-based spectrum plasma wave receivers have the disadvantages of a large size and a narrow dynamic range. This paper proposes a new type of FFT-based spectrum plasma wave receiver that overcomes the disadvantages of conventional receivers. The receiver measures and calculates the whole spectrum by dividing the observation frequency range into three bands: bands 1, 2, and 3, which span 1 Hz to 1 kHz, 1 to 10 kHz, and 10 to 100 kHz, respectively. To reduce the size of the receiver, its analog section was realized using application-specific integrated circuit (ASIC) technology, and an ASIC chip was successfully developed. The dimensions of the analog circuits were 4.21 mm × 1.16 mm. To confirm the performance of the ASIC, a test system for the receiver was developed using the ASIC, an analog-to-digital converter, and a personal computer. The frequency resolutions for bands 1, 2, and 3 were 3.2, 32, and 320 Hz, respectively, and the average time resolution was 384 ms. These frequency and time resolutions are superior to those of conventional FFT-based receivers.

Highlights

Space is filled with plasmas, and plasmas in low-density regions, such as Earth’s magnetosphere and solar wind, are collisionless
Because these collisionless plasmas exchange their kinetic energies through plasma waves, the measurement of plasma waves is essential in understanding the physical processes occurring in space; plasma wave receivers have been used on past scientific satellites focused on the investigation of space plasma phenomena
A waveform receiver has become common in scientific missions; waveform observation should be intermittent because it produces a large amount of waveform data relative to the capacity of the satellite telemetry

Summary

Introduction

Space is filled with plasmas, and plasmas in low-density regions, such as Earth’s magnetosphere and solar wind, are collisionless. Zushi et al.: One-chip analog circuits for a new type of plasma wave receiver waveform receiver having poor observation capabilities for relatively weak plasma waves in the high-frequency range Another disadvantage of the waveform receiver is its power consumption. When the frequency spectrum is obtained with a good frequency resolution, the onboard digital processing unit must process a huge amount of waveform data This requires a high-performance digital processing unit, leading to further increases in the necessary resources, such as the power and size of the receiver. The sampling frequencies of the analogto-digital converters (ADCs) and the gains of the main amplifiers change synchronously with the changes in the filters This synchronization enables the measurement of plasma waves in an appropriately defined receiver dynamic range with a reasonable power consumption. The present paper introduces the design and specifications of the developed analog component and demonstrates its performance as a FFT-based spectrum receiver based on the experimental results of the developed chip

New type of the FFT-based spectrum receiver

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Conclusion