1. um GaAs HEMT HEMT -

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

Prof. Wu, let him to check if he can follow the design goals to build a module.

3. We received a formal quotation from NRAO for 4 units of 82~106 GHz amplifiers, delivery for the first two units is on or before

Nov. 31, 2000, delivery for the remaining 2 units is on or before July 31, 2001. Now, await Fred's approval for ordering .

4.No news from Todd Gaier for loaning two units of JPL's LNA modules, Huei will follow up it.

5. Huie has modified the design goals for MMIC components; Paul will email that sheet to everyone to review after this meeting.

6. Mal said he got the first chip back from TRW for InP LNA, at present they try very hard to get them into the amplifier test, as

M. Sinclair

H. Wang

H.Wang

H. Wang

K.Y. Lo

P. Shaw

H. Wang

Ongoing

DONE

ASAP

Done

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 said 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. He will talk with Paul about later to see what he think.

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 last week we heard TRW will deliver them in

early September. Presently, he is working on the 4 GHz lag correlator by using the commercial Gilbert Cell multipliers, he should have

something comes out in a couple of weeks, he hopes.

5. Layout of the circuit board - Jeff is thinking about how to layout the circuit board to accommodate the correlator self, LN DC

multipliers, converter and custom chips. He thinks those item probably take us a good realistic, and may be a square inch or two? if we

are lucky. Warwick is also thinking a little bit about how to put them together, he thinks we need more information to figure out a lot of

J. Peterson

J. Peterson

J. Peterson

J.Peterson

Ongoing

ASAP

ASAP

ASAP

1. Mintang decides to use the Daikin cooler, with a student's assistance, the preparation work for purchasing is starting now.

2.As to the OMT, there are two available sources - NRAO & Atlantic, Mintang has been contacting both of them, once he got price

transfer the IF signal by laser beam.

2.Eugene asks Warwick that is there any information about the frequency response for the 20GHz external modulator plus laser for the

photonic system ? Warwick says he has a spec. sheet, it shows for a 3dBA band, the frequency is 2 ~ 20 GHz. Eugene currently is looking

for the components for the photonic LO system, and he found the phototec laser. He thinks we don't need to use controller, so we can cut

down the price about half. We only need the narrow frequency adjustment, the original price is about 9,500USD, and the head is only

5,500USD. Warwick says this is good news, and he will close look at this spec. Eugent will finish the components list for photonic LO,

he will send it to Warwick for his review and comments. Warwick says it would be a good idea to do it as early as we can for the cost

comparison between the original LO and the photonic LO system, to make sure not to get ourselves in large cost.

3.As to the photonic delay system, T.H.Chu asks Warwick that do you think is it necessary to use the delay system for AMiBA which

mentioned in your email ? Warwick says it won't be necessary if we still use a single platform for all of the 19 antennas.

But if we use a separate mounts system, it will be really a big question about delay. T.H. asks Warwick that how long is the fiber line in

your system? And how long is the delay system itself ? is that line in your array or used in your movable fiber antenna ? Warwick says

they have not built that delay system yet, they just design it. They design a system for a 13m each base line, so as the delay system they

design, to take a ±13m delay line. T.D.Chu asks Warwick to provide the modulator information. Warwick agrees to email it to Eugene.

4.Bob confirm the traveling schedule to NRAO for Eugene & Leo has been finalized with John, it is from 25 Sep. through 6 Oct. Both

5.Eugene is continuing to collect more detail and precise information from vendors of Photonic LO system components.

6.As to the fiber modulator, Warwick says it is normally available up to 20GHz bandwidth, not much more than that, they are pretty

expensive items going with the multiple mounts system. He sent some information to Eugene about the cost of various components for

photonic IF system. Eugene also found some laser modulator from other vendors, they claim their modulators can up to 30 to 40 GHz

wide band. Warwick is not sure it is really available or just under developing, but he thinks the 20GHz band width is still pretty much

pushing thing, and we need to get more information about it.

M. Sinclair

Y.J. Hwang

W. Wilson

Y. J. Hwang

H.C. Lu

ASAP

DONE

DONE

ASAP

B. Martin

M. Kesteven