A 3 Giga Sample Per Second 14-bit Digital Receiver with 9 GHz Input Bandwidth for Solar Radio Observation

Abstract

A new digital receiver with excellent performances has been designed and developed for solar radio observation, which can receive the radio signal from direct current (DC) to 9 GHz in the direct acquisition way. On the digital receiver, the analog-to-digital converter (ADC) with 14-bit, two input channels and 3 Giga Samples per second (Gsps) are used to acquire observed signal, and the field-programmable-gate-array chip XCKU115 acts as the processing module. The new digital receiver can be used to directly sample the solar radio signals of frequency under 9 GHz. When receiving the solar radio signal above 9 GHz, the new digital receiver can save 1–2 stages of frequency down-conversion, and effectively improve many indexes of the solar radio observation system, i.e., the time resolution, analog front-end circuit, weight and volume of the analog circuit system. Compared with the digital receiver with sampling rate below 1 Gsps used in existing solar radio telescope, the new digital receiver reduces the frequency switching times of large bandwidth, which is beneficial to improving the frequency and time resolutions. The ADC sampling resolution of 14 bits, providing a large dynamic range, is very beneficial to observing smaller solar eruptions. This receiver, which would be used in the solar radio observation system, well meets the latest requirements with the resolutions of time (≤1 ms) and frequency (≤0.5 MHz) for fine observation of radio signals.