AMiBA PROJECT WEEKLY MEETING MINUTES

Date: 15 February 2001

Participants: B. Martin, H. Wang, W. Warwick, M.Sinclair, H.C. Lu, Y. J. Hwang, W. Ho, Homing Jiang, P. Shaw, Jackie Wang, Jean Cheng

Issues and Description

Action by

Output
MMIC

1.        Regarding the HPF purchasing issue, Leo will contact the supplier and tell them we would like to purchase the first 5 units for prototype, and we will purchase 35 units more once the first 5 units is accepted by testing, and ask the supplier to give their best offer to us.

2.        As for inquiring TRW for the price of InP HEMT & HBT MMIC foundry run, Huei will send a schedule plan to TRW. Huei thinks the InP foundry run schedule should be based on the existing design of JPL, and we should loan some modules from JPL to verify whether they are good for our prototype or not, and if JPL agree to loan some module to us. Another back up action is to put our design on ATNF’s HBT chips, since a wafer run t will be carried on in June this year for their own purpose, Mal says. Mal agree to talk about that idea with the people in charge in ATNF, and then contact TRW through the existing contract channel to see whether TRW accept the a.m. collaboration on the InP HBT wafer run for AMiBA. And we should point out to TRW that the InP chips will be directly shipped to Hawaii or via ATNF to Hawaii.

l       Schedule plan for InP HEMT MMIC:  1st run - end of 2001, 2nd run - 3rd quarter of 2002;

l       InP HBT MMIC: 1st run – 2nd quarter of 2002.  

3.        Since we got approval for the InP export license, so Todd thinks they probably could ship the units through TRW on the export license. Huei will talk with TRW people to see whether they could do this service on us.  

4.        Jean already sent a copy of the InP LNA measurement result from NRAO to everyone to look, and in the mean time Mingtang inputs two plots of the Trx VS Frequency for the NRAO LNA on web site as well. He will talk with the designer when he visit NRAO by next week, and see if they could make the rest of 2 units better.

5.        No response from Spacek about mixer and amplifier, and T.H. will keep in touch with Spacek, Eugene says.  Eugene got a quotation for mixer and HPF from Russian firm, it is $3,000 USD each mixer and $1,200 USD each HPF, deliverable in 8 weeks, and the conversion loss is only 6~8 dBA for the mixer. This will be an option for the post amplifier.

6.        As an alternative for the past amplifier, Mal will take a look at the InP mixer chips which they have designed for their own, to see if they can modify the package design to suit our needs. Mal will follow up to collect all drawings for machining and packaging, and send them to Mingtang and Bob. In the mean time, Mingtang and Eugene will contact Chungshang Institute to see if they can do the machining & packaging for that mixer chips.

7.        Mingtang and Eugene will contact the Chungshang Institute to discuss the packaging issue for the Sub-harmonic mixer chips

8.        Regarding the wafer run for the 0.1um GaAs HEMT chips, Huei says due to TRW raise their price from $120k USD to $185K USD, and is difficult to get money from NSA /CIC to make the wafer run in this year. However this change will not affect the prototype fabrication.

9.         Due to the problem of the Specek amplifier, we need to find an optional post amplifier for receiverMal says they don’t have the suitable GaAs MMIC chips for our post amplifiers needs. however Mal will keep on looking for the opportunity to use the ATNF InP HBT chip for the post amplifier.   

H.C. Lu

 

  

  

H. Wang

M. Sinclair

 

 

 

 

 

 

 

 

 

 

 

 

H. Wang

 

 

 

M.T. Chen

 

 

 

 

T.H. Chu

 

 

 

 

M. Sinclair

M.T. chen

Y.J. Hwang

 

 

 

 

M.T.Chen

Y.J.Hwng

 

 

 

 

 

M.T.Chen

H.C. Lu

M. Sinclair

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Lag Correlator Hybrid

1.        Huei says a model of GaAs HBT from CIC /Taida shall be provided to ATNF/Paul Robert in this March..  

2.        Regarding the InP HBT multipliers, Warwick says the packaging test is under way.

3.        Eugene contacted the ACX in Taiwan; he got an offer back from ACX, and forwarded it to Warwick as well. According their offer, Warwick thinks the biggest problem is they don’t have experience in doing the print resistor, and we have to use this resistor in the lag correlator. So he thinks we need to look for some other manufacturers. Warwick will do it in a couple of weeks. Ray says the IC chips will be back from CIC in March, and before that he is working on another chip design of voltage converter, it will be completed in March also. Regarding the LNA, it is difficult to find that chip in die form; Ray will keep on looking for that.

4.        Warwick asks Bob does he hear any comment back from the science team about how to fit the prototype measurement with two correlators instead of two. Since Bob didn’t attend that telecon, so Warwick will follow up with Michael.

5.        Regarding the 16-element correlator basis on mixer using power divider circuit, Jeff says they are continuing to test the individual mixer using noise source. now they are going to measure the stability of the output, but they don’t have sensitive enough equipment to see the fluctuation of the output. So they will add the LNA to the output, and see if they can measure on that. In mean while, he is still waiting for out put of the producer for lag correlator, he will keep on pushing them. Jeff will be gone in the next two weeks to south pole, so he hopes something comes out when he backs.

H.Wang

W.Warwick

W.Warwick

 

W.Warwick

 

 

R. Wei

 

 

 

 

W. Warwick

 

 

 

Peterson

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Receiver

1.        Mingtang tested the window material, which supplied by Jeff in the last week; he found that material is very good. Besides its cost is much cheaper than the commercial one. He will finish the test on that material and send the results to everyone to look. Mal also will send a sample to Mingtang as well. 

2.        Warwick says he received the resent work plan of Mingtang by email from Jean, and it is readable. So Jean will follow up to resent all work plans to everyone as she did before. As to the project schedule, Jean will resent the schedule in the Microsoft Project 98 version as well.  

3.        Regarding the circular polarization issue, Mal has read the information from Jeff. and he will be modeling on that. He will let us know what is going on afterward.

4.        Mingtang will visit ATNF from Feb. 27 to March 4, he will discuss with Mal about the receiver design in details, including feed horn.

5.        Eugene says that our mechanical engineer West Ho and himself almost finish RX components layout in the cryostat, the only problem is we need a little bit higher space inside the chamber to put the stainless wafer guide flange for the temperature difference. They also generate some special wave-guide section drawing, and will send them to the firm in USA for quotation.

 

M.T. Chen

 

 

 

J. Cheng

 

 

 

M. Sinclair

 

M. Sinclair

M.T. Chen

M.T. Chen

Y.J. Hwang

W. Ho

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IF/LO

1.        Warwick has received the technical data of fiber laser system from Eugene, and he agrees to buy one from IAA. Eugene will talk with Warwick about the purchasing procedure in detail afterward.

2.        As to the optical fiber, Bob suggests Eugene should look for other alternative in the market, and discuss with John about alternative as well. In the mean time, Bob will try to get the quotation from Sumitomo through the Smithsonian people. Mal will send some cable information to Eugene to look.

3.        Regarding the Q band sub harmonic mixer design, Eugene will make a back up plan for using the 0.5 um GaAs chip instead of the 0.1um GaAs chip. He will continue looking for a commercial available MMIC chips on that mixer.

 

Y.J.Hwang.

W. Wilson

 

Y.J. Hwang

B. Martin

M. Sinclair

 

Y.J.Hwang

 

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Platform/Mount/Dishes

 

 

1.        Philippe received some drawings of the small dishes from Bob; he will start working on those drawings by today. Bob will work out a summary of the optics in the coming day. 

2.        As to the mount, Bob will work out some drawings and send them over to Vertex and Chungshang Institute before he visit vertex by next Thursday & Friday, after that he will come to Taipei. The general overview on the prototype system including time schedule in a regular basis is necessary:

Paul will place the work plan of each sub-system in prototype as well as the time schedule on the web site, so everyone could take a look. We will talk on those work plans in detail by next week.

 

P. Raffin

B. Martin

B. Martin

 

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Next Meeting

7:30pm EDT, 8:30am Taiwan, 10:30 Australia, 4:30pm Tucson/Thursday/Feb. 22, 2001