AMiBA Engineering Telecon Minutes

13, Jun, 2002

Participants:	USA: B. Martin, J. Peterson, D. Kubo
	Taiwan:	K.Y. Lo, P. Ho, H. Wang, C.T. Li, Y.J. Hwang, H.M. Jiang, W. Ho,
		C.C. Han, C.J. Ma, K.Y. Lin,T.H. Chiueh, P. Wu, G.C. Liu, U. Keiichi

Summary

General:

Fred introduced Paul Ho to AMiBA science team and engineering team and announced Paul will take over both positions of IAA director and AMiBA PI from him. He assure to everyone that even he left he will keep his eyes on AMiBA and get involved as much as he can. Paul said that AMiBA is a critical project, SMA is more and less rolling and AMiBA is in the build up phase, very important for the institute. And it's also important  to do it as quick as we can, because of the competition over there so many projects. He asked everybody work harder as usual and help him as much as possible to understand where the problem areas are.

Correlator:

1. Derek has proposed a reduced correlator block diagram for everyone to read and comment. All agreed that we should go ahead to do it.

2. C.T. has measured  the squared terms from each lag of 2 correlators, with 2 noise sources of -7 dBm IF power at correlator inputs, and demodulation disabled as well as the rms values as IF power is varied. He also circulated to everyone to read. He will measure the smr value with Marki mixer and correlator sometime in the next week.

3. C.T. got the Triquint amplifier yesterday, he will test it today and tomorrow.

4. Derek mentioned that the main schedule driver for the entire correlator acivity work is the delivery of correlator module, we originally needed 91 plus 9 spare to give 100 in total,  if we go with the reduced configuration, we only need each box 21, so it will be 42 plus 7 for calibration and 5 for spare, and then total is 54. So we actually about half, that helps a great deal, we by may be 8 months for 100 modules and may take 5 months now.  He needs the detail of dc amplifier from Warwick, C.T. will follow up and send what he has to Derek.

5. To understand what the various noise levels, Jeff asked C.T. to figure out the calibration of correlator counts in units of brightness temperature at the receiver flange and in units of voltage at the correlator output. C.T. will follow up on this with Warwick.

6. Jeff said that two biased mixers of Meridian will be shipped to Taipei by next week.

LO/IF:

4 equalizers are ready for testing, and Prof. Chu got all phase switches and assemble into the LO. It will be finished in a week or so.

Receiver:

C.T. said that we need to check the system noise of receiver again when we got the LO & IF back.

Eugene said that we are also trying to get rid of the first isolator in front of receiver to reduce the noise temperature, if it works the noise temperature will be reduced a lot. We need one week more to insert the wave guide section and remove the isolator. Eugene and C.T. will follow up on doing these works.

Mount:

Bob and Philippe had a telecon with Vertex early this week, progress is moving on schedule.

Philippe will visit Vertex on next Monday & Tuesday.

Platform:

Philippe and Ted are still working on the modeling.

60cm dish:

Philippe is still working on the FEA study of Miliflect dish.

As for the far field range measurement on 30cm dishes, C.J. and K.Y. will carrying on it after they got the adapter in a day or two.

MMIC:

The final layout for the InP HEMT chip design will be finalized with TRW very soon, Huei updated.

As for purchasing the 28 LNA of JPL, Hilo office received the contract document from JPL. Bob will follow up on the purchasing process immediately.

Action items:

1. Derek/ Derek has proposed a reduced correlator block diagram , and according his estimation, this new approach will save 40% cost. Derek will follow up to put together a package describing the 2 correlator approaches (4 products/baseline vs 2 products/baseline) and circulate to everyone to read.

2. Derek/ Derek is planning to purchase the first section IF distribution, 4 way power divider, directional coupler, he will discuss the details with C.T. offline shortly.

3. Ted We got a quote from Dr. Ong, Ted will arrange a telecon for bob and Philippe to go over the quote with Dr. Ong and his colleagues shortly.

4. Derek How to extend the proposed correlator module configuration of 13 element to 19 element and what is the feasible approach, Derek will figure it out in a week.

5. Proty Proty will talk to C.T. and Derek offline to know more about the correlator.

6. Tzi-hong/ Tzi-hong will summarize the argument of science issue relevant to the technical requirements and the priority, so that we could define the raw map accordingly.

7. Proty/ Tzi-hong/ Kin-wang Regarding the test plan and the observation strategy for prototype, Proty, Tzi-hong and Kin-wang will discuss together by offline and come back to science telecon next week.

Next telecon: Thursday, June 20, 8:30AM Taipei time (10:30AM Sydney time, 10:30PM EST, 2:30PM Hawaii)