AMiBA Engineering Telecon Minutes

10, Jan., 2002

Chair: B. Martin

Participants: M. Kesteven, R. Gough (Sydney), J. Peterson (USA),

H. Wang, T.D. Chiueh, M.T. Chen, C.T.Li, Y.J. Hwang, H.M. Jiang,

W. Ho, Ted Huang, C.J. Ma, P. Shaw (Taipei)

Summary

MMIC:

1. Huei is still working on the non-linear model of InP HEMT from TRW, he will keep on contacting TRW in order to get problem resolved ASAP.

2. Todd Gaier will help in testing the forth stage LNA , he will send the housing drawing to Huei once approved by JPL.

3. End-Feb.is still the target to finish InP HEMT chip design and send to TRW.

Correlator:

1. Jeff has received two units of lag correlator and checked it out, it works pretty good and little better than before. It seems responding nicely all the way to 18GHz and a reasonable delay line step from stage to stage. Jeff thinks it is what we need for prototype. He will send one unit to Warwick tomorrow, and keep the other one at CMU for further testing. He will check with Warwick

Monday morning to see if ok with Warwick.

2. Jeff had a discussion with Andy Harris on the lag correlators. Andy reminded Jeff it is absolutely

essential to measure both delay right and left, and he wonder why the tape delay line circuit did not

work and he suggested the power dividers is the better way to go.

Prototype mount:

We ordered a turn table from Vertex, Nederland for prototype mount. It will ship to Viola in two weeks time.

Philippe will ask the packaging and shipping firm to prepare the document required for temporally import to Hawaii.

Vertex mount:

Philippe will set up a visit to Vertex sometime this month.

Platform:

Philippe is working on the platform modeling, nothing really reported yet.

60cm dishes:

Philippe is contacting Quinstar and Milliflect to find out what exactly they can supply.

Optical telescope:

Mike send a note for optical telescope to Bob, Bob will go over it and get back to Mike. He thinks a 6 inch one is good for prototype using, and he will follow up to get quotations for that.

Receiver:

Cold test will be started tomorrow, this time is aiming at noise performance over frequency band. Mingtang hope to finish cold test for two receivers by end this month, in the mean time he will try to measure the beam pattern of feed horn with receiver cold. He is still looking for the final quote from vendors for electrical cabinet. Honming is still working on the control hardware and software. Mingtang is also working on the dewar modification for the secondary iteration of dewar design.

30cm dishes measurement:

Mingtang thinks to measure the beam pattern for feed horn is doable at receiver lab with existing set up, but he is not sure whether doable for 30cm dish or not at this moment .

Site visit:

We received annual report 2001, work plan 2002 and poster from Tzi-Da and annual report 2001 from Huei as well.

Action items:

1. Russell/Huei/ Russell will investigate when is available to test the GaAs HEMT chips at AT for Huei, Huei will send chips & probes to Russell afterward.

2. Russell/Huei/ Russell will test the noise figure the InP LNA chips to measure the noise figure for Huei.

3. Russell/Huei Russell will help to investigate whether AT can release the InP LNA model to Huei.

4.Jeff/ Jeff will ask Andy Harris to send his work references or comments on lag correlator to us.

5. Jeff/ Jeff will provide a broad band mixer to Mingtang to measure the signal correlation with two receivers.

6. Paul/ Paul will follow up to track down the delivery status of IF amplifiers with local agent to Milteq.

Next meeting: Thursday, 17, Jan., 2002 at 08:30AM Taipei time.