1. name1 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Developement - FIDA3 Timothy Finn FG-IGN t.finn@oan.es José Antonio López Fernández, Daniel Segovia, Enrique García, Vicente González, José Luis Vázquez, José Manuel Serna, Oscar García Pérez 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn

2. name2 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Overview DS4-T4 Antenna design & simulations Noise Simulations Construction of FIDA3 Characterisation of FIDA3 performance Conclusions 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn

3. name3 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Overview DS4-T4 establishes that the FG-IGN will be responsible for the design, developement, construction and characterisation of a 1m 2 ultra wide band aperture array These elements should be low cost, dual polarised, and optimised for RF performance from 300 – 1000 MHz. In addition overall design should yield lowest possible noise figure to maximise Aeff/Tsys sensitivity FG-IGN has three specific roles to play in DS4-T4 –1 : Model an entire antenna tile accounting for mutual coupling effects –2: Develop soultions for integrating active elements with the antenna elements with optimised coupling –3 : The charactersiation of system performance over a range of ambient temperatures 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn

4. name4 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn Vivaldi Variant Bunny Ear Antenna TSA technology allows a potentially low cost planar antenna to be designed Differential feeding No need for balun Provides a UWB antenna from 300 -1000 MHz Design problem : Scan blindness in band Old solution : Cross Wall New Solution : 3 kΩ resistor to dissapate even mode current

5. name5 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn Design Problems and Solutions

6. name6 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn Total System Noise Simulated System Gain > 20 dB Simulated Total System Noise >70 K

7. name7 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn Construction The antenna design has been fixed (1 m 2, 64 antennas, ʎ /2 seperation@1GHz) Al ground plane of 1.5 mm and FR-4 post and frame of 2 mm Construction of the antennas has already begun Full integration forseen by year end or early 2009.

8. name8 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn Construction

9. name9 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn Construction

10. name10 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn Measurements AIV campaign has already begun Hot/Cold facility at Astron will be utilzed for Tsys measurements Open range available at the National Aerospace and Telecommunications centre near Madrid. Backup facility near Yebes

11. name11 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn Hot/Cold Measurement will be undertaken using the sky as the cold source and an ambient temperature absorber load using Astron facility Should be done for range of frequencies in the band (at least ends of band and centre) Caesar will be used to verify the measurements of Tsys including sky noise Measurement Concept – Hot/Cold

12. name12 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn Plan to measure radiation pattern in cuts and full spherical map to broadside. Absolute gain allows calcuation of Aeff and hence sensitivity. Open Reflection Range is optimised to mitigate RFI and to limit non- propagation related diffraction. Measurement Concept – Beam Pattern

13. name13 title 4 th SKADS Workshop, Lisbon, 2-3 October 2008 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Progress in Active Antenna Design and Development Tim Finn Conclusions Years 1,2 and 3 have seen an evolution from preliminary evaluation and feasability study to a fully functional, theoretical array. Year 4 activities will focus on integration of antenna array, beam forming network and DLNAs with the goal of minimising system noise and thus maximising sensitivity Characterisation of array is planned to begin by first quarter of 2009