HIGH FREQUENCY UPGRADE OF EUROPEAN ANTENNAS

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HIGH FREQUENCY UPGRADEOF EUROPEAN ANTENNAS

• ALESSANDRO ORFEI
• IRA-INAF, ITALY

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PROPOSED JRAs and INTERESTED PARTIES

• mm-VLBI (43, 86GHz at least)
• FPA (up to 100GHz array)
• VSOP-2 (up to 43GHz receiver)

• Would some european antennas use high frequency
  FPA
• Would some european antennas partecipate to
  mm-VLBI
• Would some european antennas enhance cm-range up
  to 3mm
• Would some european antennas partecipate to VSOP-2

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EUROPEAN ANTENNAS
Most of them have full efficiency at cm
wavelengths (5-10GHz)
Effelsberg has usable antenna at 86GHz because of
large diameter

• Medicina, 32m ?22GHz _at_?min/20
• Noto, 32m ?22GHz _at_?min/20 now 43GHz, expected
  86GHz
• Cambridge, 32m 22GHz
• Torun, 32m ?32GHz _at_?min/20
• Effelsberg, 80m is upgrading antenna at 86GHz

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KEY INGREDIENTS FOR UPGRADING

• ENHANCE PEAK GAIN, i.e. UPGRADE SURFACE ACCURACY
• 1a. ENHANCE PRIMARY and SECONDARY MIRRORs
• 1b. ENHANCE ALIGNMENT PERFORMANCE
• GET A CONSTANT GAIN AT ALL ELEVATIONS
• 2a. INSTALL AN ACTIVE SURFACE

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UPGRADING NOTO
Panels0.085mm rms Sub0.35mm rms Align.0.2mm rms
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WHAT ACHIEVABLE
PANELS 0.065mm rms (available,
SRT) SUBREFLECTOR 0.05mm rms (available,
SRT) EXPERIENCE on ACTUATORS (avavilable,
NotoSRT) ALIGNMENT 0.05mm rms (?)
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FEASIBILITY STUDY

• Gravitational deformation of each antenna ?
  actuator stroke
• Mechanical interface between actuator and back-up
  structure
• Mechanical interface between actuator and panel
• Mechanical constraints of secondary mirror
• Contacting manufacturers for prices and
  delivering time

TIMELINE AROUND 1 YEAR
COSTS interface prototypes, mostly travel among
partners, 50K/antenna(?)
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EXECUTIVE PHASE
TIMELINE for 4 ANTENNAS DELIVERING ABOUT
1000 PANELS, 65?m (4 x 32m panels)
2-3Years DELIVERING 4 SECONDARY MIRRORS,
50?m WITHIN PANELS TIMELINE DELIVERING ABOUT
1000 ACTUATORS WITHIN PANELS
TIMELINE INSTALLING ACTUATORS, PANELS and ROUGH
ALIGNMENT 3-4 MONTHS/ANTENNA FINE ALIGNMENT
to 50?m 3-4 MONTHS/ANTENNA(?)
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COSTS FOR THE EXECUTIVE PHASE
NOTO 32m LIKE ANTENNA (at italian prices) 250
PANELS (65?m), ?580K/antenna
SECONDARY MIRROR (3.2m,50?m),
?120K/antenna 250 ACTUATORS,
?450K/antenna INSTALLATION,
?120K/antenna FINE ALIGNMENT,
?80K/antenna TOTAL
?1.35M/antennaTAX
COMPARE COST AND TIME WITH CONSTRUCTING A NEW
ANTENNA WORKING AT FULL EFFICIENCY _at_ 86GHz.