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Issues and Description
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Action by |
Output |
| General |
Fred mentioned that according the TAW8 meeting on science,
a very strong message showed that we got to hurry up. As for the CMB
polarization experimentation,we have to do it ASAP. He have been talking
to Mike and Ravi about proposing a plan to build up from the prototype
staged enhancements so that we can embark on CMB polarization measurement
ASAP. It means, all the critical components needed to be done at faster
time scale, including receiver, correlator, and everything else. May
be we don't need all 19 elements and everything on line,
but we need to go through it. That's the background come up with what
we are
dealing with. Tony Readhead is coming on the 21 August; so far he
has still
not expressed his intention of collaboration with us on CBI. But Fred
thinks
we can't depend on what he intend to do. So either way, Fred thought
we need
to speed up what we need to do. Fred proposed to organize a meeting
for all
of us to review what we are doing. |
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Ongoing |
| MMIC |
- Bob mentioned he had a phone conversation with Stacey about
the InP HEMT foundry issue, and she feels we round and round a
circular without a result. The bottom line is we need to get a
definite plan what we are going to do for the InP HEMT foundry.As
for the existing contract, Stacey expressed we can revise it if
it is not enough,but we can not put on Sandy design on it, since
that will change the contract and need to start all over. But
if we want to do all in US then we have to come up a detail proposal;
we want to have how many wafer chips, we want use some sort of
design and how we get approval from them, who is going to do the
packaging and testing, and any person who touch the wafer chips
should guarantee he will not export. Jeff thinks the best approach
is to follow what UMass did, and may propose the idea of UMass
contract to Stacey to consider. So the next step is to figure
out what we are going to do, for example, where to do the packaging
and test. Fred suggests arrange another telecon to go over that
issue ASAP.All agreed to have a meeting on next Tuesday morning
9AM Taipei time. Participants are Fred, Huei,Bob, and Jeff. Mal
and Paul. Paul will follow up to set up the telecon connection
ASAP. In the mean time, Huei will wrap up a proposal and send
to everybody to look at in advance.
- Huei mentioned Todd told him today the four modules are ready
to ship to us, and Todd also showed the test result to him. Todd
also mentioned to him that Challis Laurence will meet Tom Prince
this week, and he hope to get some answers back on the collaboration
issue which Challis brought up to him in July.
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H. Wang
P. Shaw
H. Wang
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Action item
Ongoing
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| Lag Correlator Hybrid |
- Jeff mentioned there is one complete 17-element correlator based
on mixers alumina, and they test today for the first time.The
result is disappointing, they are not getting the response as
they expected from the correlator. They are getting an average
cross path band they want about 2% of the response they expected,
and he don't know why the response so low. They have been doing
a little discussion here about why they are getting such low response,
and he is interested in the opinion from Warwick and others on
why will be as low as it is. One could probably use these devices
in a prototype correlator for using in testing the array, but
that will require more drives than we are planning. So that will
change our plan in the prototype correlator, it's not something
he will consider for the full-scale unit of current condition
just now response or not. He thought the best thing to do is for
Warwick, him and Jeff Rapadas to have a separate discussion about
where to go next. The basic idea is using the mixers in the delay
line lag correlator, he thought it sound the mixer have single
element mixer does have the frequency response we want, it does
have low noise level we want, but our implementation there is
17 element correlator in the alumina is working out. So this brings
out what the next step is. Jeff suggested set up a separate
telecon to discuss the technical details with Warwick; he will
summarize a plan for discussion in advance.
- Tzi-Da has come back from Switzerland, and has been showing
up at this meeting. He mentioned he has read Warwick's comments
of test on the CMOS output end chip, and he has also sent back
a proposal to Warwick by email in yesterday. Tzi-Da will discuss
with Warwick further by offline. Fred thought we need to set up
a number of phone call to go over that area in details, and to
come up with an action plan. Paul will follow up to organize
the telecon to go over the correlator issues.
- Tzi-Da mentioned he will try to revise the existing chips to
get it work, otherwise they need at least 3 to 4 months to get
another new chips. For details, he will discuss with Warwick by
offline.
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J.Peterson
T.D.Chiueh
P.Shaw
T.D.Chiueh
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Action item
Action item
Ongoing
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| Receiver |
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| Mingtang mentioned all components for prototype
have been ordered and should be delivered to us on time, the only
uncertainty is the OMT. So far NRAO did confirm us the shipping date
for that. Mingtang will follow up to check the status with NRAO person.
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M. Sinclair |
Ongoing |
| IF/LO |
- Leo mentioned he received some information from Warwick, and
he has discussed this information with Pro.Chu as well. And they
thought there is one point needed to clarify; that is how much
input power required for the correlator? Since Prof. Chu will
do the equalizer circuit, and we will integrate the amplifier
to the equalizer. Pro. Chu is preferring to us a low power amplifier,
and put it inside of the correlator, so that he don't need to
package this amplifier outside the correlator.
- As for the power budget, Leo will send it to Warwick to look
at after discussing with Mingtang.
- Eugene mentioned he tested three of the four photo mixers, and
the test results were reasonable and identical with the test report
of the manufacturer. However their performance were 10 dB lower
than the theoretical modeling expected. He wrote an email to NRAO
engineer for opinion, and he got some opinion and suggestion back
on how to adjust the test procedure in order to improve the test
result. So he will follow this suggestion to re-test those photo
mixers.
- As for integrating the tunable lasers with the fiber output,
Eugene mentioned he just starts to make a coupling from the laser
head to optical fiber. He will get more technical data from the
manufacturers in order to find a way to get a reasonable the coupling.
And he is respecting the coupling efficiency will be as high as
70%.
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H.C. Lu
H.C. Lu
Y.J. Hwang
Y.J. Hwang
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Ongoing
Ongoing
Ongoing
Ongoing
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| Platform/Mount/Dishes |
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| Computer control ,software |
| Mike mentioned the software board for prototype should
be completed in a couple of weeks. |
M.Kesteven |
Ongoing |
| Site Acquisition |
| Bob mentioned we need to come up with a proposal to
contribute something for using the site at Mauna Loa. |
B. Martin |
Ongoing |
| Next Meeting |
| 7:30pm EDT,8:30am Taiwan, 10:30 Australia, 4:30pm Tucson/Thursday/
23 August 2001 |
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