Atacama Large Millimeter/submillimeter Array Karl G. Jansky Very Large Array Robert C. Byrd Green Bank Telescope Very Long Baseline Array Engineering Opportunities at the NRAO’s Central Development Lab Morgan McLeod and John Effland NRAO Central Development Lab

Radio Telescope Block Diagram 2 Central Development Lab

Student opportunities include: – summer, – intern, – co-op, and/or – graduate 3 Building a National Partnership for Future STEM Leaders, Howard University, 30 Aug 2015

Central Development Lab R&D areas of interest: – Advanced integrated receivers – Phased array feeds – Low noise amplifiers – Cryogenic mixers – Precision Array for Probing the Epoch of Reionization (PAPER) Subject areas: – Analog and Digital Electronics – Microwave Engineering – Software Development 4 L-Band ( GHz) Integrated RF-to-Baseband-to-Digital-to- Optical converter module

Central Development Lab Fully-integrated Analog-Digital-Photonic receivers: – 1.2 – 1.7 GHz for Phased-Array-Feed: 40 channels, 100 Gbps total output on 40 optical fibers with unformatted serial data links Heat sink from 3-D printer – 2-4 GHz single-channel receiver element: 4-bits, 620 MHz dual-sideband 5 Gbps total output on 2 fibers 5

Central Development Lab 6 Reflectionless Filters – Absorbs stop-band power rather than reflecting it back to the source. – Reduces out-of-band interactions with non-linear components (mixers, multipliers, ADCs...) – Patented, now licensed to Mini- Circuits. (measured data)

Central Development Lab Precision Array for Probing the Epoch of Reionization (PAPER) – 200 MHz Transitioning to Hydrogen Epoch of Reionization Array (HERA) – 10 to14-m mesh reflectors. – 24 x 24 array 7 Rich Bradley training South African students for the 64-element PAPER array

Central Development Lab Electromagnetic (EM) Designs – Polarization Splitter – Skills in EM simulation CST Quickwave – Microwave measurement techniques – Mechanical layouts GHz OMT developed and fabricated by the CDL for the GBT galactic center pulsar receiver.

Central Development Lab Cryogenic Low Noise Amplifiers – “Chip and wire” designs – Monolithic Microwave Integrated Circuits (MMIC) Analysis Measurements – Cryogenic test system 9 Cryogenic 100 GHz Amplifier

Central Development Lab Software Areas – Signal Processing – Test system improvements Upgrade LabVIEW measurement software Upgrade browser-based analysis software – Javascript – PHP – MySQL – Extjs Improvements to cryogenic cold loads 10 ALMA cryogenic receiver test system (211 – 275 GHz)

Questions? 11 ALMA cryogenic receiver (85 – 960 GHz)