Chalmers University of Technology Research Activities on Eleven Feed: 1-13GHz Eleven Feed and Dual Band (C/Ku) Solution based on Eleven Feed and Choke Horn Jian Yang, Xiaoming Chen, Adeel Yasin and Per-Simon Kildal Chalmers University of Technology Göteborg, Sweden COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Background: Alternative wideband feed technology Feed developed at UC Berkley COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Log-periodic feeds for reflector antennas Example: Lowest frequency 500 MHz Old technology New technology The Eleven antenna: 11 times smaller ……-and better Breakthrough in wideband technology COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Idea behind Eleven feed new invention • Two parallel dipoles over ground ( Eleven configuration) – equal E- and H-plane patterns – Beamwidth constant with frequency – phase center is locked to the ground plane – low far-out sidelobes and backlobes. • Decade bandwidth by – Log-periodic array – Folded dipoles COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Previous developed Eleven antennas for Green Bank for RATAN telescope for radio telescope for 150 – 1700 500 – 3000 MHz MHz. COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology CAD drawings (left) and photos (right) of 1-13 GHz Eleven feed Feed mounted between upper and lower support foam. Without upper a support foam. COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Input impedance analysis including center puck using “3 software method” (Chen Xiaoming) Center puck S1P SN P7 R e f File="D :\users\default\centerpuck_prj\data\FoldPlt.s1p" S-parameter S1P SN P2 1 Re f File="D :\users\default\centerpuck_prj\data\FoldPlt.s1p" 1 S1P SN P9 IN R Re f File="D :\users\default\centerpuck_prj\data\FoldPlt.s1p" R 1 ISO T erm R =50 O hm 1 H ybrid180 T erm 2 H YB2 1 Re f N um =2 Loss=0 dB Z =50 O hm S1P G ainBal=0 dB 1 2 1 1 0 1 1 9 SN P8 PhaseBal=0 2 8 File="D 1 :\users\default\centerpuck_prj\data\FoldPlt.s1p" Re f CST center puck model 3 Re f 7 S1P 4 5 6 SN P3 1 Re f File="D :\users\default\centerpuck_prj\data\FoldPlt.s1p" D eem bed12 S1P SN P10 SN P5 IN File="D :\users\default\centerpuck_prj\data\centerpuck.s12p" R File="D S1P :\users\default\centerpuck_prj\data\FoldPlt.s1p" R 2 ISO SN P4 T erm R =50 O hm 1 H ybrid180 File="D :\users\default\centerpuck_prj\data\FoldPlt.s1p" T erm 1 S1P H YB3 N um =1 Re f SN P6 Loss=0 dB 1 Z =50 O hm File="D :\users\default\centerpuck_prj\data\FoldPlt.s1p" G ainBal=0 dB Re f PhaseBal=0 ADS integration Antenna S-parameter WIPL-D antenna model COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Measured and simulated reflection coefficient 0 -2 simulated by WIPL-D simulated by 3-software-method -4 mearuement -6 Reflection coefficient(dB) -8 -10 -12 -14 -16 -18 -20 2 4 6 8 10 12 Frequency(GHz) COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Radiation patterns in 45 deg plane COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Dual Band Solution based on Eleven Feed and choke horn Simulation model photos of prototype COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Reflection coefficient for Eleven Feed Simulated and measured data and the set-up of measurement COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Reflection coefficient for choke horn Simulated and measured data and the set-up of measurement COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Coupling between Eleven and horn Simulated and measured data and the set-up of measurement COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Radiation patterns for Eleven 6GHz 6.5GHz COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Radiation patterns for horn 15GHz 10.5GHz COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Conclusions for 1 – 13 GHz Feed • Reflection coefficient below -10 dB up to 7.5 GHz. • 3-software-method can give much better prediction up to 13 GHz with much more computational efficiency. • Measured radiation patterns agree with simulation. But there are shoulders in measured radiation patterns for high frequencies. • The used kapton film is not proper type which causes unacceptable loss in the feed. We are manufacturing a new feed by using much lower loss dielectric films and hope the loss will be reduced. COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Conclusions for dual-band solution • Good performance at both bands • Low loss at both bands • Easy for manufacturing • Need to do more research to reduce the gap between the two bands COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
Chalmers University of Technology Thank you COSTic0603 ASSIST April 10, 2008 Limassol, Cyprus
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