AMiBA PROJECT WEEKLY MEETING MINUTES

Date: 19,October 2000

Attendants: J. Peterson, W. Wilson , M Kesteven, H. Wang , M.T. Chen, C.H. Lu, Y.J. Hwang, C.W. Lu, P. Shaw,

J. Wang

Issues and Description	Action by		Output
MMIC- W- Band InP HEMT LNA
1. Regarding the Sub Hamonic Mixer¡¦s chip test at ATNF, Mal says the target date to do that test should be in the end of this month. 2. Huei says that the first design for the InP HEMT MMIC is ready, and now is waiting for the wafer test data from JPL. Todd told him that he needs two weeks more to work out that test data. Fred says he will visit Pasadena in a week time. So Huei will inform Todd about Fred visit and ask him to arrange an appointment with the person in NASA who is responsible for the export license approval. 3. As for the 0.1um GaAs HEMT, Huei says they will finish the layout touch up and send the chip out to TRW by Oct. 20. 4. As to the export license application for the InP HEMT of TRW, Huei says Joyce told him that the review process is still ongoing at the State Department He is expecting to get a final decision on that issue by early November. 5. Wave-guide filter ¡V Huei received some experiment data from Mal by fax, Mal will provide some drawings to Huei as well, and Huei will forward those data and drawings to Prof. Wu. This would be a good reference to Prof. Wu to develop his design in parallel. (Mal is modifying the existing design of 80 GHz to 85 GHz as we need.) As for the prototype receivers, Mal suggests Mingtang to investigate if he can find the required filters in the market. 6. As per NRAO¡¦s request, we released a formal purchase order to NRAO for purchasing the 4 units of 82~106 GHz amplifiers. Mingtang will directly contact NRAO¡¦s engineer in order to get some technical data, including the layouts of amplifier. 7.Mal says that he received a reminder the wafer is back this week, the plan is to test more chips in the next couple of weeks. All the hardware of the amplifiers blocks in completed, so he expects to start to test that w-band InP LNA chips sometime by end next week. So he hopes to work out some test results in three weeks. Huei says Specek answered him by fax on 12 Oct., it is not possible to make the conversion loss of the mixers lower above 100 GHz, and now the 2 mixer-doubler assemblies are ready to be shipped. Leo will talk to Prof. Chu all about and ask him to make decision on relative contract issue. Huei says that they have some back up plan, if ATNF could help us to package the mixers we have, besides we have several design on going, including HBT, two HEMT versions designed by Eugene. Warwick suggests we should keep the Specek one for prototype using and design a better one by ourselves for production using. Mingtang says that considering the space restriction for receiver, we need to specify the bias circuit as we purchase the relevant MMIC components.	H. Wang M. Sinclair H.Wang K.Y. Lo H.Wang H.Wang M.Sinclair H. Wang M.T. Chen H.C. Lu MT. Chen H. Wang T.H. Chu H.C. Lu		ongoing ongoing Oct. 20 ongoing ongoing ASAP ASAP ASAP ASAP
Lag Correlator Hybrid
1. Jeff will report by next. 2. Warwick says that they have made some measurement on the HBT Gilbert Cell multiplier wafer, the result is quite similar with the simulation, and he think there is a possibility to use that multiplier up to 16 to 20GHz bandwidth. Warwick will collect more measurement data, generate a report, and send over to Huei and Jeff to take a look. 3. Paul, Eugene and Leo met the ACX Company's people at the "Taitronic Exhibition" on last Thursday¡¦s afternoon. They brought our inquiry back to the headquarter for further study, and will give us an answer late this week. Paul will keep on looking at it. 4. Warwick says he got the low bandwidth prototype working now, got the first spectrum the other day, and it is working quite nicely at the 3 GHz bandwidth, simulate the result of Andy Harris shown. He is doing a test on it at this moment, trying to figure out what the frequency response has on the performance. And he thinks it looks quite promising to work with the 3 GHz bandwidth correlator. 5.Huei says that they finished the design work on the Gilbert Cells Multiplier, but there are some Problem unsolved. So he will talk to Paul Robert to find out a solution.	W.Warwick P. Shaw H. Wang		ASAP ongoing ASAP
Receiver
1. Mingtang is working on the dewar layout; he is waiting for the mount layout. He has not decided yet the overall size, because he is still waiting for the data of some components in dewar, e.g. wave-guide. J. Kingsley is working on the mount layout; Paul will contact Jeff to know the status. Leo will speed up the components sourcing progress to collect sufficient data in order to finalize the layout design ASAP. 2. Mingtang received a mail from J. Payne about the collaboration on the development of NRAO OMT. In this collaboration, U of Arizona machine shop would make parts for 8 OMTs (3 for NRAO, 2 for Wollack and 3 for ASIAA); we will pay three of the eight. NRAO provides drawings to the U. Arizona shop, ASIAA assembly all of them and make the test. Wollack measures 2 units to confirm the result. Mingtang and Yugene think we should be able to do the testing. But for assembling, we should ask for a detail description. So, Mingtang will ask John to provide a quotation and a detail assembly description for OMT production. Jeff says that Wollack may be the only person knows how to do it, and he also thinks this probably good for our people to learn by doing it. 3. Mingtang is also working on the feed horn design; he will work out something and circulate to everyone to look at during this week.	M.T.Chen P.Shaw H.C. Lu M.T. Chen M.T. Chen		ongoing ASAP This week
LO/IF
Eugene just generates a NRAO visit report today; he will circulate it to everyone to look at. We will put it on the ASIAA web site, and welcome everyone to take a look and to comment.		Y.J. Hwang	ASAP
Platform/Mount/Dishes
1.Bob will send over a draft layout for mount and dishes to everyone in a week or two after. 2.Jeff doesn¡¦t think the caesarian could work with the 30cm antenna due to its high ground pick up. He will do some quantitative analysis to demonstrate this case. 3.Regarding the height of ground shield for our antenna, Bob requests Michael to ask their expert to verify what size is good for us? 4.Mingtang says our new engineer assistant C.W.Lu fould a local expert in the field of Hexapod. The expert, Prof. Perng, leading a lab in the Department of Power mechanical Engineering of The Tsing-Hua University. Prof. Peng has more than 10 years research experience on Hexapod, and he is very interest in the AMiBA work. So Mingtang will invite him over to ASIAA to give a talk on what he knows and what he think about our mount.		B. Martin J. Peterson M.Kesteven M.T. Chen	ASAP ASAP ongoing ongoing
Site acquisition
Bob says that he plans to visit Mauna Lao Observatory by the second week of November, to take a look on site and see what the possibility is and how we proceed.	B. Martine		Ongoing
Prototype Specification and Project Book
1. He got some contribution receiving drawings last day or two, we he will incorporate all of these into a revised draft, he will send it to Fred and Paul by the end of week. As a center source of all documentation there, and that is what has to be worked with others for further contribution on all chapters. Fred will take over the question with. 2. Bob and Fred asks Michael, Ravi and Bob to take a close look at some technical related science issues, e.g. UV coverage with current design on platform and drift scanning techniques, observation strategy and photonic delay line. 3. Michael inputs some comments on the antenna layouts; Philippe also feed something back to Michael as well. As to the secondary mirror supporting structure, Jeff will collect some material information and send it over to everyone to look at.	B. Martin M.Kesteven J. Peterson		Ongoing Ongoing ASAP
Visitor
Darrel Emerson Oct. 9~11 / J. Payne Oct. 9~16
Traveling
Bob / Oct.9 ~ Oct. 26, Fred / Oct.14~Nov.1
Next Meeting
8:30pm EDT, 8:30am Taiwan, 10:30 Australia, 5:30pm Tucson/Thursday/ Oct. 26. 2000