Desenvolvimento de um espectrômetro de RFI de baixo custo e portátil para o radiotelescópio BINGO

Abstract

The BINGO project aims to construct an innovative radio telescope to map neutral hydrogen emission within a redshift range of z = 0.13 to z = 0.45, with a focus on its ability to detect Baryon Acoustic Oscillations (BAO), a phenomenon caused by the interaction of matter with radiation in the primordial universe. The radio telescope operates in the frequency range of 980 to 1260 MHz, and to ensure measurement quality, it is essential to monitor radiofrequency interference (RFI). In this context, the BINGO project adapted the CALLISTO spectrometer, a programmable receiver traditionally used for solar burst observations, to cover the 900 to 1300 MHz range and monitor RFI. This study proposes the development of a low-cost, portable spectrometer for RFI monitoring, utilizing the MAX2121 integrated circuit, a direct-conversion tuner operating from 925 MHz to 2175 MHz. This circuit includes components such as a low-noise amplifier (LNA), RF variable gain amplifier, in-phase (I) and quadrature (Q) mixers, as well as low-pass filters and baseband amplifiers with digital control. Inspired by the CALLISTO spectrometer, this new project aims to enhance RFI monitoring, contributing to the integrity of the data obtained by the BINGO radio telescope and strengthening the conditions for advancing studies on the expansion of the universe and the nature of dark energy.