AMiBA PROJECT WEEKLY MEETING MINUTES

Date: 21 December 2000

Participants: H. Wang, W. Warwick, M. Sinclair, 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. Leo presents a simulation result on HPF, comparing the ¡§image rejection ratio in dB¡¨ among the specs of original, ATNF and proposed one. Due to the increase value of image rejection ratio compared with the original specs is only 1.7dB, Huei suggests Leo to make a spread sheet further on that simulation in order to verify whether it is worth to revise the original specs or not. Warwick says that if we increase the low frequency of the IF up to one GHz that will improve greatly, and he thinks that¡¦s going to happen. Any correlator we use is unlikely to go much below 1.5 GHz. So we should use an IF of 1~20GHz frequency range, and we will no go better than that. Leo will talk to T.H. about this issue. In the mean time, Mal is working on the filter fabrication and testing. 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 on design. As to loan some modules from JPL, Todd has promised to write a task description report to NASA for approval. 3. Regarding the Specek's amplifiers, Leo say that T.H. told him the Specek¡¦s agent in the States has received the amplifiers, and he thinks the delivery date may be after new year.	H.C. Lu H. Wang T.H. Chu			ongoing ongoing
Lag Correlator Hybrid
1. Huei received a revised specs for the Gilbert Cell Multiplier from Warwick, and the noise performance for the ATNF InP HBT multiplier may not be good enough for AmiBa According the calculation result, the multiplier adds about 10% to the output fluctuations therefore decreasing the sensitivity by 10%, and it is equivalent to a 10% increase in Tsys. Warwick will discuss this result further with Michael to see how to solve the problem. Warwick will provide the technical data of InP HBT chips to Huei. Huei will ask students doing a noise analysis on the circuit of GaAs HBT process. 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			ongoing ongoing
Receiver
1. As per request, Mal will provide a temperature sensor board to Mingtang. 2. Regarding the collaboration proposal on the development of NRAO OMT, John is working on pricing and time schedule in details. 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. As to the multi hole coupler, Mal says that a real one will be worked out in a couple of months. 5. Yugene will provide Mal the technical data, price and company information of the noise source, which made in Russia. 6. 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.	H.C. Lu B. Martin Y.J.Hwang M. Sinclair		ASAP ongoing ASAP ASAP
IF/LO
Yugene will send the technical data of fiber laser system to Warwick; Warwick will take a look to see if it is suitable for his need.		T.H. Chu		ASAP
Platform/Mount/Dishes
1. We are waiting for the final quotation for the prototype dishes from the firm ¡§Composite Mirror Application, Inc.¡¨ Bob and Kingsley will generate some preliminary drawings to show the interface between dish, receiver and mount, and send them over to Mingtang and Philippe to look at. 2. Bob is working on a quotation from Vertex for the feasibility study and pricing according the different specification of mount and platform. We hope to get it done in the beginning of Jan.		B. Martin B. Martin		ongoing ongoing
Next Meeting
7:30pm EDT, 8:30am Taiwan, 10:30 Australia, 4:30pm Tucson/Thursday/Jan. 4, 2001