AMiBA PROJECT WEEKLY MEETING MINUTES

Date: 4 January 2001

Participants: B. Martin, H. Wang, T.H. Chu, M.Kesteven, M.T. Chen, H.C. Lu, Y. J. Hwang, P. Shaw, J. Wang, Jean Cheng

Issues and Description	Action by			Output
MMIC- W- Band InP HEMT LNA
1. Follow up the conclusion on the HPF simulation in last meeting, Leo changed the IF frequency to 1~ 20GHz and re-do simulation, he found the image rejection ratio in dB increase to more than 40 dB. For our original specs of HPH, the ratio becomes to 42.6 dB, and 48.3 dB for ATNF HPF. As for the system temperature. He reviewed the previous noise calculation, the estimate there is 1 dB loss of the HPF, and it will cause less than 1 degree system noise temperature. Leo will make a report on that simulation and circulate to everyone to take a look. So we will finalize the specs in the next meeting, and then start purchasing process right away. 2. Huei have sent the initial layouts of the InP HEMT chip to JPL; he has discussed the noise model with Todd, and is doing the final trading off on design. As to loaning some modules from JPL, Todd has promised to write a task description report to NASA for approval. 3. T.H. has received the Specek¡¦s amplifiers, he will test them ASAP.	H.C. Lu H. Wang H.Wang T.H. Chu			ongoing ongoing ASAP
Lag Correlator Hybrid
1. Huei received a performance table of InP HBT from Warwick before X¡¦mas shut down, now his student is studying it and trying to work out a comparison matrix, to see how feasible for the GaAs HBT stuff. So he will follow up and inform us the progress by next week. Warwick updated and clarified by email that the noise performance of the ATNF InP HBT multiplier should be able to meet the specs of AMiBA according to his recalculation result. Huei is checking whether the GaAs HBT can do the same work or not. 2. Regarding the InP HBT multipliers, Warwick says that wafers have not gotten back from TRW yet, and in the mean time Paul has been getting the packaging and test fixture ready. He is also continuing to talk to the ACX in Taiwan about the LTC module for lag correlator using HBT multipliers. 3. Ray has sent Warwick a lot of information about the possible DC amplifier to follow the multiplier. Warwick says that in line with the latest information we have on noise, we need to reconsider there exactly what noise performance we need. Ray and Warwick will keep on looking for the available commercial chips.	W. Wilson H.Wang W. Warwick R. Wei			ongoing Ongoing ongoing
Receiver
1. As per request, Mal will provide a temperature sensor board to Mingtang. Paul asks Mal to provide the cost information as well. The commercial board for 8 channels will cost $1000USD each. 2. Regarding the collaboration proposal on the development of NRAO OMT, John is working on pricing and time schedule in details. Mingtang is concerning about the testing schedule, and it would be better to know earlier. Bob will follow up this issue with John. 3. Regarding the vacuum window material, Mal will send a sample to Mingtang, and then Mingtang will do the transmission measurement on it. 4. Yugene sent Mal a copy of the technical data, price and company information of the noise source, which made in Russian. 5. Mal will look at the summary on receiver design, which prepared by Mingtang; he will get back to Mingtang if any thing is needed to clarify. 6. We have a new member today ¡V Mr. West Ho, he is our new mechanical engineer just join us from Dec.	M. Sinclair B. Martin M. Sinclair Y.J.Hwang M. Sinclair		ongoing ongoing ASAP Done ASAP
IF/LO
1. Yugene sent the technical data of fiber laser system to Warwick; Warwick will take a look to see if it is suitable for his need. 2. As to the optical fiber (5 meters long), Yugene is still waiting the quote from Sumitomo. Sumitomo announced they will discontinue that production, but they will check their stock to see if could find some. He also has problem to get the quote for Erbium doped fiber optical amplifier, he will send both of the specs to Bob, John and Warwick, to see if they could help him to find out the source of supplier. 3. Bob says that since our focus is back on the single platform, somebody should be looking seriously at the high quality cable, but not necessary one of this, what is the best approach, what is die-electrical or just standard hard line for IF return. This probably something that Yugene, Leo and T.H. should look into it.		T.H. Chu Y.J. Hwang Y.J. Hwang H.C. Lu T.H. Chu		ASAP ASAP ASAP
Platform/Mount/Dishes
1. Kingsley is doing more drawings in detail for the dishes we are working with the vendor in Tucson. We should have a final quotation and all prices together by the end of this week. Bob says the design is looking for using the compositive construction sandwich for the primary surface of both cases. As for the edge, we decide to use the shell and catch that rigidly around the cylinder around the edge of primary, and then attach the fed leg to there. So we get very stiff structure by using the shell of the part of mechanical structure. 2. As for the platform, what we are looking at now is a single platform around 6 meters. Bob is trying to place a proposed design and design study with vertex, and a feasibility study of what real way could be, what real pricing, performance, etc. We got a quotation from Vertex, Paul is working on that. We should probably go ahead with that in a week or two. And that will be a design study bottom, it last too long. That really put it in place how the feasibility real proceeding with such platform, what real cost would be, and then how to do next.		B. Martin B. Martin		ongoing ongoing
Work plan
We had a quick review on the work plan right after this telecon with Huei, T.H., Mingtang, Yugene, Leo, Paul & Jackie. All agreed to update their work plan, purchasing requirement, man power and cost for the year 2001. We will discuss this further more in the next meeting.
Annual report
Annual report should be submitted to Jean before Jan. 10.
Next Meeting
7:30pm EDT, 8:30am Taiwan, 10:30 Australia, 4:30pm Tucson/Thursday/Jan. 11, 2001