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

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

3. 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.

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

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

7. 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.

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

9. 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

10. The New Band 6 CTS Architecture
The biggest reason for rebuilding the Band 6 CTS is because LabVIEW 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

12. 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

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

14. 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

15. 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

16. 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

17. 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

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