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This custom plate assembly was design to generate and distribute 2 to 18 GHz wide-band noise or CW tone for in-situ calibration and test of the I/Q down converters and digital backend correlator system. The plate is mounted on the platform and is controlled remotely via Ethernet.
Noise/Tone Calibration Plate, YTLA Project
Photo of the bottom side of two IF Processor chassis under construction in Hilo office. Visible are the four 0-2 GHz baseband channels, DC power supplies, and ADAM monitor and control. IF processing and down conversion sections are on the far side.
IF Processor Chassis, GLT Project
Internal photos of Block Down Converter instrument: left - top view of RF brackets (x4), and monitor & control; right - bottom view of DC power supplies (x4), local oscillator plates (x2), and baseband plates (x4). Developed at the SMA project office by Derek Kubo, Ryan Chilson and John Kuroda for the SMA wideband upgrade project, this instrument provides signal conditioning and frequency translation of sixteen 8-12 GHz intermediate frequency channels from the eight SMA antennas. Two of these instruments were deployed to the Mauna Kea facility with a full suite of control software developed by Ranjani Srinivasan.
RF Block Down Converter Chassis, SMA Project
This photo represents the first production in-phase/quadrature down converter designed for the YTLA project as an upgrade to the AMiBA analog correlator system. The design was based on the results of a prototype development conducted the previous year.
In-Phase/Quadrature Down Converter Production Bracket, YTLA Project
Photo of wide-band radio frequency translator plate. This prototype provides signal conditioning and frequency translation of a pair of intermediate frequency channels to baseband for digitization.
Early Prototype Down Converter Plate, YTLA Project
Internal photos of the Laser Synthesizer instrument. Left - top view of optical components including FBG assembly that houses optical filters, couplers and switch; Amonics erbium doped fiber amplifier along with other auxiliary items. Right - bottom view consisting of Centellax RF power amplifier, Sumitomo Mach Zehnder modulator, DC power supplies, and ADAM monitor & control.
MZM Laser Synthesizer, ALMA Project
Internal photos of LORTM instrument. Left - top view of optical components including Sumitomo Mach Zehnder modulators (x2), Centellax RF power amplifiers (x2), Amonics erbium doped fiber amplifier, fiber Bragg grating filters, along with other auxiliary items. Right - bottom view consisting of DC power supplies, ADAM monitor & control, TexaXion laser, and Miteq IF power amplifier.
Local Oscillator Reference Test Module, ALMA Project
Internal photos of Laser Synthesizer instrument: left - top view of optical circuitry including Erbium Doped Fiber Amplifier and custom Fiber Bragg Grating filter assembly; right - bottom view of RF power amplifier, Mach-Zehnder modulator, DC power supplies (x3), and monitor & control. Developed at the SMA project office by Derek Kubo and Ranjani Srinivasan in collaboration with NAOJ, this instrument was designed to provide a pure optical local oscillator reference for distribution over long distances of optical fiber (Kubo et al. Aug 2013, IEEE T Microw Theory: 61(8), 3005-3014).
MZM Laser Synthesizer LO Source
In May 2017, the GLT make the very first-time integration test from receiver to the backend recorder in ASIAA-Hawaii laboratory. Since the instrument rack is not delivered on time, the cable is not routing organized. However, the injection tone signal from RF window is recorded in the backend recorder as expected.
System integration test from receiver to Mark 6 recorder
The cryostat chamber mounted on an alumina holding structure (The dewar frame) shown in the center of the picture. Except for few instruments fixed on the dewar frame, most frontend hardware is installed into 36U height rack that locates on dewar left and right side. The vacuum pump sits under the dewar with long bellow pipe connect to the dewar chamber.
GLT Frontend System
From observations of Orion-KL, the HCO+ and HCN lines were detected using the prototype digital correlator for AMiBA.
Orion-KL observations using AMiBA prototype digital correlator
Srinivasan, Ranjani
Software Prog/Scientist
photo of Srinivasan, Ranjani
Office: Hilo 212
808-961-2939 / 808-961-2983
Email: rsriniva_replace2@_asiaa.sinica.edu.tw
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