Presentation #533.04 in the session “Radio, mm and sub-mm Instrumentation and Performance”.
The Mapper of the IGM Spin Temperature (MIST) experiment aims to measure the global redshifted 21-cm signal to study the evolution of neutral hydrogen in the intergalactic medium (IGM) and of the first compact objects during the Dark Ages, Cosmic Dawn, and Epoch of Reionization. MIST has recently seen progress in the development of the third generation of the instrument. In my presentation, I will introduce the new RF analog chain, which has been designed with the purpose of unifying the input switching stage used for calibration and the amplification stage of previous designs into a single PCB. I will briefly discuss RF design considerations implemented into the PCB, which is based upon the Grounded Coplanar Waveguide design, such as RF impedance, shielding, and isolation considerations. I will then describe the different sections of the PCB, paying particular attention to the semiconductor devices - RF switches and amplifiers - that have been selected and implemented to ensure that the new design is highly power-efficient and miniaturized in comparison to previous versions. I will summarize the input and output ports of the circuit and all the possible signal paths within the PCB. I will also present examples of S-Parameter testing of on-board components, and display both images of evaluation boards custom-designed for MIST to test the components as well as figures characterizing their S-Parameters. Each figure will be briefly discussed to motivate the reasons for choosing the components and to describe their performance. At the end of my presentation I will mention the tasks left for future work, which include the manufacturing and testing of the new RF analog chain in both the lab and field prior to being implemented into the science-grade instrument to measure the 21-cm signal.