Possible Instrumentation Development Items for SKA at ASIAA

1. Possible Instrumentation Development Items for SKA at ASIAA Chau-Ching Chiong (ASIAA) and Yuh-Jing Hwang, Homin Jiang, Chao-Te Li

2. Outlines • Back-end • ADC + ROACH • Fast Fourier Transform Spectrometer • Front-end • Antenna, MMIC devices for • SKA-mid : 500MHz -10GHz • SKA-high : 10-25GHz • Summary

3. AMiBA Backend Upgrade • Digital backend using Gsps ADC + ROACH (Re-configurable Open Architecture Computing Hardware - a stand-alone FPGA processing board from CASPER) for molecular line observation, solve bandwidth smearing • Wideband (2 GHz), high-resolution (2 MHz) digital correlator • Integrate phase switching technique to reduce systematics cross power spectra with and without phase switching

4. Additional LO (LO2) + IF circuits + Digital backend for AMiBA 2 LO2 + IF backend

5. 5 Gsps ADC e2V 5Gsps chip 4 bits, demux 1:2/8 bits no demux 2GHz Bandwidth.

6. 10Gsps ADC Design Concept – Parallel Port MMCM D7 : D0 CLKDIV CLK OSERDES 1-bit/1.25GHz CLK BRAM D7 : D0 CLKDIV CLK OSERDES 4-bit/1.25GHz 4-bit LVDS/2.5GHz GTX Transceiver D7 : D0 CLK CH A D7 : D0 CLKDIV CLK OSERDES 4-bit/1.25GHz BRAM D7 : D0 CLKDIV CLK OSERDES 4-bit/1.25GHz 4-bit LVDS/2.5GHz GTX Transceiver D7 : D0 CLK CH B D7 : D0 CLKDIV CLK OSERDES 4-bit/1.25GHz ZDOK BRAM D7 : D0 CLKDIV CLK OSERDES 4-bit/1.25GHz 4-bit LVDS/2.5GHz GTX Transceiver D7 : D0 CLK CH C D7 : D0 CLKDIV CLK OSERDES 4-bit/1.25GHz BRAM D7 : D0 CLKDIV CLK OSERDES 4-bit/1.25GHz 4-bit LVDS/2.5GHz GTX Transceiver D7 : D0 CLK CH D D7 : D0 CLKDIV CLK OSERDES 4-bit/1.25GHz Xilinx FPGA XC6VLX130T 10Gsps ADC ANST7120-KMA D7 : D0 CLKDIV CLK OSERDES 1-bit/1.25GHz CLK Prototype at the coming August

7. One Baseline Correlator for AMiBA 2 • Studying the possibility of low-z red shift. Stay at W band, only migrate analog correletor to digital correlator • Deployment could be in the coming Autumn 2012 Original analog correlator ROACH digital correlator

8. 4 Antenna Packetized Correlator Collaborate with CASPER

9. The Fast Fourier Transform Spectrometer • CIDRE is a project of an heterodyne receiver embedded under a stratospheric balloon • Its goal is to detect the OH and HD molecules with fundamental transitions near 2.5THz and 2.7THz • The IF signal coming out from the mixer will be at 3GHz. • The most challenging points about this FFTS are: • -Its processing frequency (3GHz) • -Its power consumption and its cooling • At this altitude (40km), there is almost no air so it is very difficult to cool the FFTS. That is why we need to create a power efficient FFTS.

10. We are working on MMIC key components for many years… PLL board Packaged MMIC LNA MMIC VCO MMIC filter MMIC mixer

11. Feed Antenna • Broadband dual-polarization planar antennas to eliminate the requirement of waveguide orthomode transducer, thus reduce the mechanical size. • Low-loss MEMS switch would be used to switch between different bands. Slot antenna for two polarizations (Berkeley) + Horn (NRAO)

12. RF and IF Low-Noise Amplifier • Experience on ALMA Band-1 development. • Tsys < 30-35K, Tn for LNA should be < 15K • Use low-noise GaAs or InP HEMT technology with cryogenic cooled down to 77K or 15K • Cryogenically cooled IBM SiGe BiCMOS as alternative choice • If un-cooled, we need 100x numbers of element to reach the same noise level.

13. Antenna Integrated Rx Module Feedhorn SIW with planar probe (NRAO) 180˚ hybrid + filter (NTUEE) Or Slot antenna for two polarizations (Berkeley) LO source and PLL or VCO as ADC clock signal LNA Mixer + IF amp. or ADC

14. Summary • Possible items on SKA instrumentation are identified. • For back-end, high speed ADC and new digital correlator are the core technologies. • For front-end, MMIC-based devices might be the main contribution from ASIAA, mainly for SKA-mid and –high. • Detailed evaluation on each development plan will be available later. • Additional interested items • SKA.TEL.SADT Signal and Data Transport • SKA.TEL.CSP Central Signal Processor