Development of band-1 receiver cartridge for Atacama Large Millimeter/submillimeter Array (ALMA)

The prototype cartridges for ALMA Band-1 receivers have been developed, based on the key components developed in ALMA Band-1 consortium laboratories. The prototype cartridges for each receiver consist of two parts, cold cartridge assembly and warm cartridge assembly. The cold cartridge assembly (CCA) consists of horn antenna, orthomode transducer and a pair of 35-52 GHz cold low-noise amplifiers, the amplified signals of both polarizations are transmitted to warm cartridge assembly by long waveguide sections. In warm cartridge assembly (WCA), two major modules incorporated, down-converter assembly including warm low-noise amplifier, high-pass filter, mixer and 4-12 GHz IF amplifier, and local oscillator based on a 31-40 GHz YIG-tunes oscillator. The frequency range is based on the upper sideband scheme. Based on the measured performance of the key components, the expected noise performance of the receiver will be 26-33K.