FIDA3 ( F G- I GN D ifferential A ctive A ntenna A rray) Luis - PowerPoint PPT Presentation

FIDA3 ( F G- I GN D ifferential A ctive A ntenna A rray) Luis Enrique García-Muñoz, Vicente González-Posadas, José Antonio López-Fernández 1 , Daniel Segovia-Vargas Departamento de Teoría de la Señal y Comunicaciones Universidad Carlos III de Madrid (TSC-UC3M) 1 Observatorio Astronómico Nacional

State Of The Art � EMBRACE � Single ended technology (microstrip feeding balun printed in a different board). � Single polarization (soon dual polarization). � Elements Etched in FR4 substrate. � Band: 300-1500 MHz. (-45º to 45º scan). � 1 m 2 tile = 64 antennas per polarization (antenna pitch = 125 mm). FIDA3

FIDA3

State Of The Art II � VALARRAY � Single ended technology (microstrip feeding balun printed in a different board). � Dual polarization. � Elements made in aluminum material. � Band: 600-1500 MHz. (limited scan). � 1 m 2 tile* = 56 antennas per polarization (antenna pitch = 118 mm - element spacing = 125 mm). * 64 elements is feasible. FIDA3

FIDA3

State Of The Art III � FLOWPAD3* � Differential technology. � Dual polarization. � Elements entirely built in one layer of a thin substrate (polyester) and located in a polypropylene foam lattice. � Band: 300-1000 MHz. (-45º to 45º scan). � 1 tile = 32 antennas per polarization (antenna pitch = 165 mm). 1 m 2 of array: 36.75 antennas per polarization. * Simulated FIDA3

FIDA3

FIDA3 EMBRACE VALARRAY FLOWPAD3 FIDA3 Tech. Single Single Diff. Diff. - Extra board - Extra board - Bridge - Substrate? Fabric. - FR4 needed - Ground plane issues - Ground plane 300-1500 600-1500 300-1000 300-1000 Band MHz. (-45º to MHz. (limited MHz. (-45º to MHz. (-45º to 45º scan) scan). 45º scan)* 45º scan)? LNAs/m 2 128 128** 73.5 <73.5? FIDA3

FIDA3 FIDA3

FIDA3 antenna elements I � Bunny-Ears antenna Pitch = 176 mm � 64 LNAs/m 2 VSWR at Broadside for a 2 POL array of Bunny Ears 2.8 CST HFSS 2.6 2.4 2.2 2 VSWR 1.8 1.6 1.4 1.2 FIDA3 1 0.2 0.4 0.6 0.8 1 1.2 1.4 Freq [GHz]

FIDA3 antenna elements II � Scanning results Scanning a 2 POL array of Bunny Ears 7 H plane 45.8º E plane 45.8º H plane 22.9º 6 E plane 22.9º 5 VSWR 4 3 2 FIDA3 1 0.2 0.4 0.6 0.8 1 1.2 1.4 Freq [GHz]

FIDA3 WITH GND FIDA3

FIDA3 WITH GND EVEN MODE � � ODD MODE � � � � � � SCAN BLINDNESS NO SCAN BLINDNESS FIDA3

FIDA3 WITH GND INTRODUCING RESISTORS IN AN ODD CONFIGURATION � � � EVEN CURRENTS ARE BEING REMOVED � � � � � ODD MODE IS STILL PRESENT � � � � NO SCAN BLINDNESS FIDA3

FIDA3 WITH GND FIDA3

FIDA3 Preliminar Noise Study FIDA3

FIDA3 Preliminar Noise Study 4 3.5 3 2.5 VSWR 2 1.5 1 R WARNING: INCREASING R, 0.5 STRONG MISTMATCH APPEARS � � � � COMPROMISE SOLUTION 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 FIDA3 Freq [GHz]

FIDA3 Final Design H PLANE E PLANE FIDA3

FIDA3 feeding network I � Two outputs per tile (combining 8*8 elements for each polarization) � � � � Only broadside FIDA3

FIDA3 feeding network II design � � � � � ‘Modular’ Subarrays inside the tile � � � � access to 16 subarrays of 4 elements, 4 subarrays of 4 elements and also single output (all cases with two polarizations) Versatile and 2D scanning. FIDA3

FIDA3 feeding network III Technology: � Coaxial cables and commercial power splitters � Mixed feeding schemes: microstrip technology & commercial elements Key aspects: - Bandwidth: -Commercial power splitters � � � � -Wilkinson/T- junction based solutions � � � � - Losses � � Low noise � � FIDA3 solution

FIDA3 LNAs Balanced DA FIDA3

FIDA3 CONCLUSIONS EMBRACE VALARRAY FLOWPAD3 FIDA3 Tech. Single Single Diff. Diff. - Extra board - Extra board - Bridge NO Fabric. SUBSTRATE - FR4 needed - Ground plane issues - Ground plane 300-1500 600-1500 300-1000 300-1000 Band MHz. (-45º to MHz. (limited MHz. (-45º to MHz. (-45º to 45º scan) scan). 45º scan)* 45º scan) LNAs/m 2 128 128** 73.5 64 FIDA3