Study of potential upgrades for the ALMA Band 7 receiver

We will present the work performed during a 2-year feasibility study to assess possible upgrades of the ALMA Band 7 receivers. The main upgrade goals are to at least double the IF bandwidth from 4-8 GHz to for example 4-20 GHz, to extend the RF bandwidth to have more overlap with ALMA Band 6, and to improve the beam squint, by using orthomode transducers rather than wire grids. The study was completed in September 2023 and showed full designs for various components which could indeed allow fulfilling most of the new requirements. We highlight though that performing all these upgrades while keeping as good noise temperature as the current Band 7 will be very challenging.