APRICOT: Achievements in reporting period: 2010 Q4/2011 Q1

Task1 Architecture: not yet available Task2 Passive Systems: a) 7-horn platelet-like system to INAF design – has been measured b) polarizer: 2 prototypes ordered based on Manchester design . To be made by Forestal by

   electroforming technique

c) 7-OMT platelet-like system to INAF design : finalization of mechanical drawings d) Added to the task exploration of the feasibility for an integrated device (Q-band FEM i.e Q-band

   front end module, one per horn) able

- to connect directly each OMT output to the cryo LNA input (waveguide to microstrip transition) - to inject a known calibration noise to both receiver polarization (noise diode + directional couplers) - to include two cryo MMIC-LNAs, one per polarization

Task3 Semiconductor Devices: a) UMAN: first transistors fabricated in collaboration with IEMN Lille’s standard lithography. gate length=130nm. Measured Ft ~140 GHz, Fmax~200 GHz look promising since the semiconductor material layers are not the ones optimised for noise performance. Samples of these devices have been sent to Yebes for noise measurement. Collaboration has now been established with University of Glasgow group which has high quality e-beam lithography with standard gate length is 80 nm. First 80nm devices with superior materials expected summer 2011. b) INAF/UTV: still waiting down-conversion chips from OMMIC they should arrive in June then we proceed with testing. Also working on structures which are necessary for a Q-band receiver in particular a revolutionary waveguide to microstrip transition and a directional coupler in order to integrate the noise source for calibration purposes inside the dewar. A first design of directional couplers has been made - awaiting some accessories to test it. The waveguide to microstrip transition has been finalised - proceeding in order to build the test jigs and test it c) MPIfR: mHEMT device and MMIC programme with IAF - work with IAF independent of (but helping) APRICOT: Work in this area is ongoing with strong focus on RT and cryogenic device characterization and modelling. IAF is constantly working on the improvement of the fabrication process by incorporating data from own measurements and those from external partners from the radio astronomy community. Throughput of cryogenic testing has been clearly identified as a bottleneck for the development of cryogenic HEMT devices. IAF has invested massively in noise characterization of HEMT devices at room and cryogenic temperature. They will soon be able to perform full noise characterization at RT up to 50GHz using an improved system based on mechanical tuners. MPIfR is currently setting up a completely new cryo-prober station which will be able to do (semi-) automated testing on parts of a full wafer. This will provide a much larger number of cryogenic measurements per cooling cycle in order to supply the necessary cryogenic database to improve the statistics of the cryogenic model. The first dedicated cryogenic process run at IAF is currently underway, first devices at are expected for ~May this year.

The formal order from APRICOT to IAF on the fabrication of metamorphic MMICs using their standard 50 and 100nm processes has been placed in July 2010. First payment has been carried out in September 2010 upon confirmation of order according to the contract.

A Q-band LNA has been designed and fabricated at IAF within the CAY-IAF mHEMT device and MMIC programme. A formal decision whether this is intended to be an official APRICOT design is pending, if this is the case the design could be made available for the partners.

AMSTAR+ link: LNA modules at W-band using IAF’s standard RT process and their standard cascode design were tested at room and cryogenic temperatures. Modules cover the full WG-band (75-115GHz) at room and cryogenic temperature, so far cryogenic noise performance of NGC LNA’s has not been reached.

Other points: we have agreed with INAF-IRA to share our cryogenic facilities to do cryogenic MMIC characterization of several LNA designs. Testing of a 22GHz LNA manufactured at NGST is completed, testing of a Q-band design also manufactured at NGST is ongoing. We plan to present test data from both LNAs at the Cagliari APRICOT meeting. Characterization of a second Q-band LNA fabricated by OMMIC will follow next.

Task5 update:

a) Existing programme: - Radio telescope scanning simulations based on Torun RT-4 - Simulations and analysis of sky scanning strategies - Further development of this software will be done in the near future

b) Current development programme:

- OCRA-p/f receivers simulations - Noise analysis for OCRA-f and noise parameter estimation (MCMC and simulated annealing) - Application of noise analysis and parameter estimation for solving one of the main tasks of the APRICOT task 5: i.e. algorithmization of the queue-scheduling process based on current weather conditions as defined in terms of the model noise properties (continuously updated noise parameters) - this is not yet working but we have an idea how to do it and software that can do it. Now we need to put this into life. - Radio sky simulations CMB+SZ+… (in progress, a lot is done already)

c) Future programme:

- cross-talk simulations of various elements of the receiver system (classes that simulate OCRA-f can also be easily utilized to mimic APRICOT type reciver) (work being developed) - Weather simulations (in plans) (although this is also one of the main tasks for APRICOT task 5 it is not started yet; however an analysis of noise generated by the weather can be included in software simulations very soon) - For the moment I cannot answer whether I will be able to say whether or not it will be possible (or to what degree) to do observations through clouds with non-switched system (or with software switching). I however will be able to make some sort of relations showing eg SNR vs “cloud content” for eg. simulated OCRA-f receiver within (hopefully few month of time). - Simulated sky surveys and system optimization (eg. optimization of f_switching, etc.) this is one of the topics for the coming OCRA-F paper. - Finally, the dynamic queue scheduling / queue ordering program although not yet done, I will try to attack this problem with high priority ASAP so that some of the deliverable were ready.

List of working documents

Main Activities during

Meetings attended by people involved

Problems / Issues

Red flags - major problems

Forward Look


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