ALMA band 1 development at Universidad de Chile

The lowest spectroscopic band devised for the Atacama Large Millimeter Array (ALMA), the so-called Band 1, covers the frequency range from 31 to 45 GHz. This band was not implemented during the rst construction phase of the telescope, but will be included during a second ALMA development phase. During the past 4 years our group has been working on the development of technology to cover this band, complying with the demanding ALMA specications. Among the most burdensome challenges are the stringent specications on noise temperature, the large required bandwidth, and the limited space available for this receiver within the ALMA cryostat. In this paper we present some of the technologies we have developed, including the design of key components like horn, lens, ortho-mode transducer, and low noise ampliers. We also present an evaluation of third-party components which can be used in the receiver. The work is used to present a preliminary layout of the Band 1 receiver.