Technologies for Tunable Antennas Holger Maune Technische - - PowerPoint PPT Presentation

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Technologies for Tunable Antennas Holger Maune Technische Universitt Darmstadt Institute of Microwave Engineering and Photonics maune@imp.tu-darmstadt.de 19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

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SLIDE 1

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Technologies for Tunable Antennas

Holger Maune

Technische Universität Darmstadt Institute of Microwave Engineering and Photonics maune@imp.tu-darmstadt.de

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SLIDE 2

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Agenda

  • Reconfigurable RF Frontends
  • Technologies for Tunable Antennas
  • Ferroelectrics
  • Liquid Crystal
  • Tunable Antennas
  • Pattern Engineering
  • Impedance Tuning
  • Conclusion
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SLIDE 3

Today‘s Technology for Radio-Frontends

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Radio Frequency Frontend Digital Backend Antenna

Mixer Oscillator Amplifier Matching Network Filtering Switch Diplexer Matching Network Digital - Analog Converter Signal Processing

F F

D A D A

HPA LNA VCO

DSP

A wide range of incompatible, hardware-related inflexible systems,

  • perating on a variety of carrier frequencies, modes and standards.
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SLIDE 4

Towards Frequency-Agile, Software-Defined, and Cognitive Radios

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Digital Backend

Digital - Analog Converter Signal Processing

Reconfigurable RF-Frontend with tunable passive components

Smart

Antennas

Mixer Oscillator Amplifier Matching Network Filtering Switch Diplexer Matching Network

F F

D A D A

HPA LNA VCO

DSP

Φ

  • Baseband (software) reconfiguration for multi-standard operation
  • Reconfigurable RF frontends with reconfigurable/tunable analog

RF components for multi-band (and multi-standard) operation

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SLIDE 5

Fundamentals of Antenna Arrays

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

I = + + +

Θ α Θ α α cos 2 2 cos 1

2 1

kd j j jkd j j

e e I e e I e I ... = ∑

− = ⋅ ⋅ ⋅ ⋅ 1 cos N n d k n j j n

e e I

n

Θ α

ζn = n⋅k⋅d⋅cos(Θ) for n= 0, 1, 2, 3...

a0 a1

Attenuators Phase shifters

+

α

1 − N

α

1

α

Wavefronts Receiver

j

E e ξ ⋅

1

j

E e ξ ⋅

1 N

j

E e ξ

−

⋅

d

Θ

Radiating elements Combiner

aN-1

Phase difference at n-th element Sum-Signal

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SLIDE 6

Example: Linear Dipole Array

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Broadside Θ0=90° Endfire Θ0=0°

Pattern changes during scanning

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SLIDE 7

Applications for Steerable Antennas

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

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SLIDE 8

Technologies for Reconfigurable RF-Hardware

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Thin Film Thick Film

Technologies for Reconfigurable Systems

MEMS LC ACTIVE PASSIVE FE Semiconductors

MMIC RFIC

Thick Film LC

Low cost technologies Low power consumption High linearity  High power application High FoM possible Compact by using MetaMaterial structures

Ferrites

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SLIDE 9

Liquid Crystal as Tunable Material for Microwave Applications

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Solid Nematic Liquid Temperature z x

n 

ε⊥ ε

uniaxial anisotropy

Isotropic Not Tunable Anisotropic Tunable Anisotropic Not Tunable Liquid Nematic Soild

εr,║ εr, ┴

Anisotropy ∆εr= εr,║-εr, ┴

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SLIDE 10

Liquid Crystal as Tunable Material for Microwave Applications

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

DC

RF V

2 ( ) ( )

r

U U π β ε λ Φ = ⋅ = ⋅  

( ) ' '( ) ( ) U U U j L C γ ω µ ε ≈ ∝ ⋅

{ }

2 ( ) ) ( ) (

r r

U U π ε ε λ ∆Φ = − ⋅

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SLIDE 11

Barium-Strontium-Titanate as Tunable Material for Microwave Applications

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

  • Large dipole moment by Ti4+ & O2-
  • Permittivity can be changed by an electrostatic field
  • Change limited by breakdown
  • Fast Tuning  ps-range
  • Passive Tuning  electrostatic field

Dielectric Tunability

εr

|E|

∆εr(E)

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SLIDE 12

Barium-Strontium-Titanate as Tunable Material for Microwave Applications

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

3D Structures

  • Deposition on

Si,MgO,LaAlO3,Pt… (400…650°C)

  • εr ≈ 100 … 600
  • h ≈ 70 … 500 nm

Thin-Films

Planar Structures

  • Screen-printing
  • n Al2O3
  • Sintering (≈ 1200°C)
  • εr ≈ 200 … 700
  • h ≈ 1 … 30 µm

Thick-Films

  • Printing of BST on

various materials

  • Sintering
  • h ≈ 70 … 500 nm

Inkjet-Printing

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SLIDE 13

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Planar Antennas

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SLIDE 14

Planar Phased Array Antennas based on Liquid Crystal Technology

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

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SLIDE 15

Planar Phased Array Antennas based on Liquid Crystal Technology

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

@ 17.5 GHz

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SLIDE 16

Phase Shifter Topologies

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Phase shifters are usually based on: Simple design & fabrication Wide bandwidth Change of line impedance  mismatching Artificial transmission line (LH) Conventional transmission line (RH)

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SLIDE 17

Phase Shifter Topologies

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Larger absolute phase constant  LH Line can be physically shorter More compact phase shifter LH RH Phase constant with higher sensitivity to a capacitance change

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SLIDE 18

Planar Phased Array Antennas based on BST Thick Film Technology

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

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SLIDE 19

Planar Phased Array Antennas based on BST Thick Film Technology

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

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SLIDE 20

Phase Shifters for Differential Signals

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Tunable differential phase shifter

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SLIDE 21

Phase Shifters for Differential Signals

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

  • Performance @ 10 GHz

Phase shift = 225° FoM = 38°/dB

Insertion loss = -12dB Leakage current < 0.2 nA @ 10 GHz

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SLIDE 22

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Volumetric Antennas

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SLIDE 23

Tunable Antennas for Inter-Satellite Communications

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

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SLIDE 24

Tunable Antennas for Inter-Satellite Communications

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

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SLIDE 25

Tunable Antennas for Inter-Satellite Communications

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

  • 20
  • 15
  • 10
  • 5
26 28 30 32 34 36 38 40

|S| [dB] 50 100 150 200 26 28 30 32 34 36 38 40 f [GHz] FoM| [°/dB] 100 225 350 475 600

∆Φ [°]

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SLIDE 26

Tunable Antennas based on LTCC

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

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SLIDE 27

Reflectarray Antennas

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

1

k0 R

n

r n r 0

n 2

N

n 1 2

Functional principle

  • Energy radiated by the feed
  • Reradiated and phase-adjusted at

each element

Phase compensation

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SLIDE 28

Reflectarray Antennas

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

  • 16x16 elements
  • All patches in a row connected
  • Beam steering in one plane
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SLIDE 29

Reflectarray Antennas

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Gain: 20.3 dB Directivity: 24 dB Efficiency: 42%

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SLIDE 30

Reflectarray Antennas

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Gain: 20.3 dB Directivity: 24 dB Efficiency: 42%

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SLIDE 31

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Impedance Tuning

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SLIDE 32

Towards Frequency-Agile, Software-Defined, and Cognitive Radios

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

Digital Backend

Digital - Analog Converter Signal Processing

Reconfigurable RF-Frontend with tunable passive components

Smart

Antennas

Mixer Oscillator Amplifier Matching Network Filtering Switch Diplexer Matching Network

F F

D A D A

HPA LNA VCO

DSP

Φ

  • Baseband (software) reconfiguration for multi-standard operation
  • Reconfigurable RF frontends with reconfigurable/tunable analog

RF components for multi-band (and multi-standard) operation

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SLIDE 33

Frequency Tunable Antenna

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune Ext.DC source

40 kΩ z y x

Using varactors to tune compact antennas to cover several bands ( e.g. 0.99 ~ 1.11 GHz with varactors‘ tunability of 30% ) Low operation current (e.g. ~ nA) allows very low DC power consumption

0.9 1.0 1.1 1.2

  • 18
  • 16
  • 14
  • 12
  • 10
  • 8
  • 6
  • 4
  • 2

0 V 50 V 90 V

Reflection Coefficient (dB) Frequency (GHz)

Equivalent Bandwidth

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SLIDE 34

Tunable Dual-Band Antenna

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

  • 3
  • 6
  • 9
  • 12
  • 15
  • 18
  • 21
  • 24
  • 27
  • 30

0.65 0.95 1.25 1.55 1.85 Frequency (GHz)

By tuning Varactor 1

  • 3
  • 6
  • 9
  • 12
  • 15
  • 18
  • 21
  • 24
  • 27
  • 30

0.7 Frequency (GHz) 1.1 1.5 1.9 2.3

By tuning Varactor 2

  • Varac. 1

Varactor 2

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SLIDE 35

Application Example for Tunable Antennas

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

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SLIDE 36

Conclusion

  • Concepts for tunable antennas
  • Technologies for tunable microwave devices
  • Prototype realizations

19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune

FE LC

Dielectric Losses Frequency