YTLA Digital Backend for CO Intensity Mapping
Chao-Te Li1*, Homin Jiang1, Derek Kubo1, Kim Guzzino1, Jen-Chieh Cheng1, Ming-Tang Chen1
1Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan
* presenting author:Chao-Te Li, email:ctli@asiaa.sinica.edu.tw
As observations of Sunyaev-Zeldovich (SZ) clusters tapered off, a new initiative was taken for the Yuan-Tseh Lee Array (YTLA, formerly AMiBA) to map CO intensity to trace the large scale structure of star forming galaxies in the early universe. YTLA, located on Mauna Loa, Hawaii, is an interferometric array equipped with W-band receivers. Since the analog correlator for the SZ observations doesn’t have enough frequency resolution, the array is being retrofitted with a digital correlator for molecular line detection. The wideband digital correlator utilizes high speed analog to digital converters (ADCs) and field programmable gate arrays (FPGAs) for signal processing and 10 Gb Ethernet for interconnection. A 5 Giga-sample-per-second (Gsps) ADC board was developed to digitize a substantial portion of the 16 GHz wide IF. Digital sideband separating technique was also adopted to double the processing bandwidth to probe more space volume.


Keywords: intensity mapping, interferometry, correlator, analog to digital conversion, sideband separation