Readout electronics for kinetic inductance detectors for COSMO

We describe the readout electronics for Kinetic Inductance Detectors (KIDs) that we are developing based on a commercial IQ transceivers from National Instruments and using a Virtex 5 class FPGA. It will be the readout electronics of the COSmic Monopole Observer (COSMO) experiment, a ground based cryogenic Martin-Puplett Interferometer searching for the Cosmic Microwave Background spectral y-distortions. The COSMO readout electronics requires a sampling rate in the range of tens of kHz, due to both a fast modulation of the signal with a spinning optical element and the short time constant of the Kinetic Inductance Detectors (KIDs) used in COSMO. In this contribution we show the capabilities of our readout electronics using Niobium KIDs developed by Paris Observatory for our 5 K cryogenic system. In particular, we demonstrate the capability to detect 23 resonators from frequency sweeps and to readout the state of each resonator with a sampling rate at about 12 kHz.