Title: FANTAIL DIPOLE ANTENNA FOR S-BAND PRECISION COSMOLOGY

Keerthipriya.S

EEG

There exist inevitable deviations in the Cosmic Microwave Background (CMB) spectrum, from that of a blackbody. One such is the distortion from the formation of the first atoms in the Universe over the Epoch of Recombination (ERA). Even in the highest signal-to-noise ratio frequency band of 2 - 6 GHz, the signal is 8 orders of magnitude fainter than other astrophysical signals. This translates to a technological challenge in designing high-precision antennas and receivers. We present a novel scalable broadband antenna design motivated by detecting these spectral distortions in the 2.5-4 GHz band. This antenna is capable of maintaining the spectral quality of the measured sky-spectrum to one part in 10^3 over the full band, and outperforms conventional broadband antennas by at least an order of magnitude The antenna's sensitivity meets the baseline design criteria for conducting experiments capable of making absolute milliKelvin-level measurements of the sky spectrum, holding potential for improving foreground models in global signal detection experiments (including those from the cosmic dawn and epoch of reionization).