ATCA and CMB anisotropies

Australia Telescope Compact Array (ATCA) observations in sky regions selected to be low in foreground confusion have been used to infer limits on arcmin-scale CMB anisotropy in total intensity and polarization. These deep searches have, hitherto, been made using the East-West ATCA in an ultra-compact 1-D array configuration and in the highest available frequency band at 3-cm wavelength. The ATCA is being upgraded for operation at mm wavelengths and in 2-D array configurations: the enhanced capabilities present a new opportunity for pursuing CMB anisotropy related observations with reduced foreground confusion and at smaller angular scales.