260 likes | 292 Views
ORA for SKA. Prof. A. K. Brown Dr. David Zhang School of Electrical and Electronic Engineering The University of Manchester Email: {anthony.brown, david.zhang}@manchester.ac.uk. Outline. A brief review of ORA aperture array antenna design at the end of SKADS
E N D
ORA for SKA Prof. A. K. Brown Dr. David Zhang School of Electrical and Electronic Engineering The University of Manchester Email: {anthony.brown, david.zhang}@manchester.ac.uk
Outline • A brief review of ORA aperture array antenna design at the end of SKADS • AA-mid Antenna design for PrepSKA • Discussions and near future plans
Aperture Array Antennas FLOTT: (a)(d) BECA: (b)(e) ORA: (c)(f)
Three candidate designs for SKADS (16×16 finite arrays) BECA ORA FLOTT (Photo Courtesy: SELEX Galileo)
Cross polarisation in the intercardinal plane at 1 GHz, based on the finite array measurement D-plane 45o Cut
Scanned element pattern for the centre element of the finite array E-plane, 0o Cut H-plane 90o Cut
Change of Frequency Range • LNA integration and feeding methods for ORA • The ORA finite array analysis • Measurement-noise temperature of integrated structure • Manufacturability
The optimisations of the feeding lines for a lower loss 3 2 1 LNA close to the radiators For LNA wiring Coaxial cable for single-ended feeding LNA above the groundplane LNAs below the groundplane, but using coaxial cables for single-ended feedings Shorter coaxial cables for single-ended feedings LNAs above the groundplane
Single-ended and differential feeding methods The single-ended stripline Differential coaxial cable feeding
ORA performance with differential coaxial cable feeds, 112mm element spacing
Single-ended Stripline feed for the 5×5 subarray of the 10×10 finite array tile The active reflection coefficient
Differential feeding method, passive reflection coefficient measured Element 13 Element 1
Integration with EMBRACE front-end electronics for further investigation
ORA tile for EMBRACE electronics integration 1375mm • The element separation of 125 mm • 70 ohms single-ended port for each element • The coverage area of the tile 1.125 m2
Efficiency measurements • Complete LNA integration and measure combined noise temperature • Manufacturability design • EMBRACE compatible tile • Final choice of LNA type and optimise ORA for mid frequency array • Build and test • Pre-production manufacturing techniques
Noise measurement of the active ORA finite array Sub-array becomes active with power splitters A hot/cold measurement facility is under construction in JBO, the measured results out of this for the finite ORA arrays will be confirmed at THACO in ASTRON
Further investigation of ORA tile with the EMBRACE electronics ? 1375mm
The manufacturing cost investigation Chemical etching: A traditional photo-lithographic technique on PTFE/woven glass laminate Ink-jet printing: A catalyst is ink-jet printed onto the plastic film, and then copper is electro-formed onto the catalyst, a further electroplating process is required Screen printing and other technics?
Efficiency measurements • Complete LNA integration and measure combined noise temperature • Manufacturability design • EMBRACE compatible tile • Final choice of LNA type and optimise ORA for mid frequency array • Build and test • Pre-production manufacturing techniques