MMIC, and he will keep us informed the result. Fred may visit Ruben late Oct in Saintbabra to see what he

is doing for the HEMT of low frequency instrument.

4.As for the 0.1um GaAs HEMT design work is still ongoing, the first design review will be made in mid of Sept., and finish the design in

Mid of Oct, so far everything is on schedule.

5.H. Wang said there is no further progress report from TRW for the export license of InP HEMT, so he will keep contacting with TRW.

6. Waveguide filter - Mal thinks it is the tough one, but from a system point of view, these numbers are reasonable. So Huei already gave it

to Prof. Wu, he will check with Prof. Wu to see if he can follow the design goals to build a module for us. Huei said that as he know

ATNF will work on that design for prototype. Mal said that at this moment they are investigating a couple of things, once he got that

data, he will talk about it more.

7. As for purchasing the 4 units of 82~106 GHz amplifiers from NRAO, in yesterday we wrote "A Statement of Ultimate & Purchaser" to

NRAO for the export license application. In the mean time, Fred approved that order as well. And once the process gone through the 4

amplifiers with them, Fred will talk to person who is planning to make the left if they don't have conflicting with the requirement. It is

the time we need to consider more about sending people to help working on them. The other alternative as Fred remember is described

that two parts of making, the first part could be made by outside company, John supposed he get quote on that, but he never did. So

it what Fred needs to follow up on. Then the other possibility is having somebody here to go and help. The issue there always is how

much time they need to train the person and how good the person is. This issue we need to bring up not immediately, but not wait too

long for the rest of amplifiers.

9. As to the MMIC design for InP LNA, Huei confirms that the design goal for the TRW wafer run and for the free ride on JPL's mask

are identical, so there is no duplicate work.

10. Leo and Eugene said that Specek postponed the delivery for amplifiers around two weeks, and they hope to get these amplifiers by

M. Sinclair

H. Wang

H. Wang

H. Wang

H. Wang

H. Wang

K.Y. Lo

M. Sinclair

T.H. Chu

ASAP

mid Oct

Ongoing

mid Sep

ongoing

ongoing

ongoing

1.For the 17 lag correlator, Jeff said the Gramic is till working on that, he don't expect anything for several more weeks.

2.For the Gilbert Cell Multiplier spec, H. Wang reminds J. Peterson to generate a specification to help S.S. Shen and his student to design

3.Huei says that according the Fushimi's paper; the diode mixer has a worse loss than the conventional mixer at RF &LO powers input. He

4.Jeff said that the email he did send around , what he realize that the signal level arriving both Gilbert Cell and mixers are quiet small, in

few microwatts (-25dBm). The division of tree structure to be made with the resistor, which make that structure much smaller. Warwick

says the resistor is much lower in the tree structure, and it certainly is the advantage to achieve that bandwidth as we talk about. The

structure will be bigger than the structure of Gilbert Cell itself, probably twice as big. Jeff will keep on thinking about an idea of merit.

He may try it, perhaps to build one.

5. Jeff said the progress of the Gramic today about switching that they are thinking for us for the tree structure and the resistance divider.

This makes the two technology re-testing as different as possible, and we learn more as we do that way, so his suggestion is that

we do that by the tree structure with mixer from that MMICs, and then we go continuously with the delay line lag correlator. Warwick

says he have not decided definitely on that structure. But he will come out some simulation with other work they do. Jeff said he would

like better for what he try, so he probably will go ahead that direction. Warwick agrees with Jeff to choose that mixer tree structure.

6. Warwick said he is still waiting for the HBT Gilbert Cell multipliers coming back, and expecting the wafer to arrive in by now , but he

can't get informaton on TRW for when they can get the MMIC coming. TRW should test it on 19th, and then see how they are going.

Warwick is still working on the 1~4 GHz lag correlator by using the commercial multipliers , he is constructing and testing it, and this

goes very well. So he hopes something comes out in a couple of weeks.

7. Warwick said he had communication with Prof. Chiueh concerning about the output processing prototype as well as the CMOS

chip design. Fred said it would be good to keep Prof. Chiueh talking to Warwick.

8. Professor Chiueh's student - Ray Wei , he makes a report on the work of "output processing IC design ". As to the "band gap reference,

he has completed the analogue system , including the close loop circuit, voltage control oscillator. And now, he is working on the digital

part and layout. He hopes finishing that work in two months.

9. As for the Gilbert Cells Multiplier, Paul Roberts and Warwick think the GaAs HEMT is worse than the HBT due to high noise and

conversion loss. Huei said they has completed 80% of the design work with the GaAs HEMT for Gilbert Cells Multiplier, he will

continue to finish that work. To solve the high loss problem, Huei suggests put amplifiers in front of RX and LO circuits. Without

testing , Warwick is wondering how practicable that solution would be. Huei decides to finish that design, and then send the test result to

J. Peterson

J. Peterson

J. Peterson

J. Peterson

J.Peterson

W. Wilson

Ray Wei

H. Wang

Ongoing

ASAP

ASAP

ASAP

ASAP

ongoing

mid Nov

J. Peterson

ASAP

1.Eugene says he is continuously working on enquiry for components and instruments.

2.Leo received the equalizer information from George, and he passed it to Prof. Chu. Prof. Chu and his students is looking at that circuit,

and so far he is doing the conventional IF system.

3.Warwick says he is working on the delay line for the AT broad band correlator, and he thinks the work they are doing should be directly

applicable for AMiBA in case we need a delay line.

Y..Hwang

T.H. Chu

H.C.Lu

Ongoing

Ongoing

• He is not convinced that approach is easy and cheap to do.
• No one had ever built a hexapod mount to support a 12m big platform.
• There is only one company we could deal with to design and to build those hexapod, too many risks.
• The biggest problem which CBI they had is the platform, the mount, the drive. As to the conventional mount approach, they made many mistakes on their design. Concerning the problem they deal with, the 12m platform is bigger than the 6m platform. If we are going to do a single platform, we need to look at the conventional mount and the hexapod mount. The conventional mount has more past experience to build for some big platform.
• As for the enclosure, we don't have any budget for a 12m telescope, besides both of the environmental conditions in Chile and in MK are difficult to use either shielding or ground screen. In MK site, the wind speed is up to 200miles per hours.
• As for the polarization experiments, all we need is a 2m platform; it is very different for the SZ experiments in many aspects.
• It looks like more and more; we are talking about two instruments.

M. Kesteven

Specification &

1.Michael says he is processing on drafting specs for AMiBA, after circulating it here he will send a copy to Bob to look at. (Paul

already emailed that draft to everyone to look at.) People could send comments to Bob and Michael for any particular area, and we can

start editing and updating on them. We should work out a book of specification for other stuff, and currently Michael is working on that.

2.We need someone to take care of the master filing for the dynamic project book, and let people know what we are doing and a lot open

issues and provide an easy access to fill in their comments, probably through web site. Bob will talk with Paul to find out a solution after

meeting.

3.Warwick reminds we need quickly to complete the specification for prototype which we are going to build up by the mid of next

year. Bob is working on that, he will try to out line some of them.

M. Kesteven

B. Martin

B. Martin

ASAP

ASAP

ASAP