Rewriting the Band 6 Cartridge Test System + Phase Stability Kendal Sandridge + Supervisor: Morgan Mcleod

Introduction to ALMA The Atacama Large Millimeter Array with 66 dishes It is used to study planetary formation

Introduction to the Band 6 CTS The Band 6 Cartridge Test System is a system for testing different specks on the Band 6 Cartridge The Band 6 Cartridge is a receiver centered on 230GHz with a band width of about ALMA receivers are split into bands because of the different sky transparencies.

Types of Measurements Phase Stability* Amplitude Stability Noise Temperature Image Rejection Beam Pattern Measurement Output Power

Components to the Band 6 CTS Power meter PNA Programmable Attenuator Switch Controller/Warm IF Plate Signal Generator

LabVIEW LabVIEW stands for Laboratory Virtual Instrument Engineering Workbench Its is a system-design platform and development environment for a graphical languages named “G” LabVIEW makes it easier to acquire data, control instruments, and automate processes.

SQLite SQL = Structured Query Language SQLite is a version of SQL that does not need a server to run. It is self- contained

Perforce Perforce is a source code control system Perforce is used instead of GIT because LabVIEW code isn’t text based and the full benefits of GIT can’t be had. Perforce allows software engineers to look back at previous changes with code and revert their current code if an bug has occurred

The New Band 6 CTS Architecture The biggest reason for rebuilding the Band 6 CTS is because LabVIEW 2013 runs 8x faster than the previous version of LabVIEW By porting the old code to the new platform we can increase test speed and efficiency

Writing Drivers The driver layer the lowest software layer in the system. This layer talks directly to the hardware Each instrument has its own way of communication Sometimes bit manipulation is involved

Ways to Communicate with Test Instruments SCPI – Standard Commands for Programmable Interfaces Ex. Other types – Attenuator A = ON B = OFF Ex. A123 B456 Turns on switches 1,2,3 Turns off switches 4, 5, 6

Writing Models Models are the next level up in the software architecture They are like a class in Java and come with an Activate which calls each function and a Validate which checks each sent and received value to see it it is valid

Phase Stability The phase stability measurement procedure involves measuring the phase of a signal over time. The phase must be stable to achieve in order for the different signals to correlate Phase stability is measured with the PNA, RF Source, Signal Generator, temperature sensor, and Warm IF Plate

Writing Phase Stability The phase stability procedure implementation is a collaboration between the Front End model, the PNA model, the Switch Controller model, the Attenuator Model and the Temperature Controller Model

Phase Stability Data Phase stability data is usually converted from degrees to femtoseconds to make the spec lines the same for each band The Alan Deviation Plot shows how much variation in phase is happening in short term intervals and long term intervals

Conclusion Over the course of this summer I successfully rebuilt parts of the Band 6 CTS up to the Phase Stability Measurement