Project:	Electrically stable antenna design for Cosmology
Disciplines:	Astronomy, Electrical Engineering
Mentor:	Gregg Hallinan, Professor of Astronomy; Director of OVRO, (PMA), gh@astro.caltech.edu
AO Contact:	Nivedita Mahesh, nmahesh@caltech.edu
Background:	Measuring the 21-cm signal from neutral Hydrogen in the early epochs of the Universe is the only direct probe to study initial cosmic structure formation and evolution. There are a number of experiments in the world designed to make this measurement. But it is difficult measurement for the signal is faint, usually 4 orders of magnitude fainter than our own Milkyway, setting strict requirements on the instrument design. One of which is the smooth response of the antenna beam. Because un-smooth beam of the antenna versus frequency can make separating the desired signal from the from the foreground galaxy difficult if not impossible.
Description:	In this the student will design antenna with electrically smooth response between the frequency range of 50 to 150 MHz. They will use a commercial EM simulation software like FEKO that has a CAD interface to model and design the antenna. They will first model antennas used by three different existing experiments, assess their properties with a common analysis pipeline. This exercise in itself will be useful for the community since the existing systems havent been compared against the same benchmark. using the results from this analysis, the student will make a better antenna design or improve an existing one.
References:	Jonathan R Pritchard and Abraham Loeb 2012 Rep. Prog. Phys. 75 086901 Mahesh, N., “Validation of the EDGES Low-band Antenna Beam Model”, The Astronomical Journal, vol. 162, no. 2, Art. no. 38, IOP, 2021. doi:10.3847/1538-3881/abfdab.
Student Requirements:	The student should have some familiarity with CAD design and modeling. Experience in coding with Python is preferred.
Programs:	This AO can be done under the following programs:   Program    Available To        SURF    Caltech students only  Click on a program name for program info and application requirements.