A multi-band dual-polarized antenna-coupled TES bolometer

We are developing multi-band dual-polarized antenna-coupled transition edge sensor (TES) bolometers for observing Cosmic Microwave Background (CMB) polarization anisotropies. We have designed a prototype pixel that uses a dual-polarized log-periodic antenna on a silicon hemispherical lens. Each polarization is coupled onto a separate microstrip transmission line. Microstrip filters are used to divide the broadband output of this antenna into a set of narrow frequency bands centered at 90, 150, and 220 GHz with bandwidths of 20%. We report on the fabrication of these devices as well as the initial optical testing.