• B-mode
• CMB
• Detection
• Lithography
• Superconducting device

The aim of the Large Scale Polarization Explorer (LSPE) is to measure the B-mode polarization of Cosmic Microwave Background. LSPE-SWIPE is a mm-wavelength polarimeter which will operate on a stratospheric balloon. Nowadays the CMB spectrum is visible in the microwaves. The use of superconducting devices, as TESs (Transition-edge sensors) and SQUIDs (Superconducting Quantum-Interference Devices), is necessary due to the CMB signal being very faint. To optimize the realisation of the readout chain the method of multiplexing was implemented: it consists in connecting the sum of the signals coming from several TESs, each of them working at a specific frequency, to a single SQUID. It leads to have less wiring noise and thermal load issues. Each TES is connected to a LC resonator which filters the signal outside the operating frequency.
In this thesis an innovative multiplexing setup was studied: it was based on the use of superconductive LC filters. We concentrated on the measurements including the use of the SQUID. We set up a complete readout chain, and investigated several issues related to defects in the fabrication of the wafers, e.g. problems of parasitic capacitance or inductance. Comparison between simulations of circuits including the LC filters and the wiring, and the data allowed us to find reasonable solutions.