Reconfigurable RF Frontends Technologies for Tunable …Reconfigurable RF Frontends Technologies for...
Transcript of Reconfigurable RF Frontends Technologies for Tunable …Reconfigurable RF Frontends Technologies for...
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 [email protected]
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
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
FFDA
DA
HPA
LNA
VCODSP
A wide range of incompatible, hardware-related inflexible systems, operating on a variety of carrier frequencies, modes and standards.
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
FFDA
DA
HPA
LNA
VCODSP Φ
Baseband (software) reconfiguration for multi-standard operation Reconfigurable RF frontends with reconfigurable/tunable analog
RF components for multi-band (and multi-standard) operation
Fundamentals of Antenna Arrays
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
I = +++ ΘαΘαα cos22
cos10
210 kdjjjkdjj eeIeeIeI ... = ∑−
=
⋅⋅⋅⋅1
0
cosN
n
dknjjn eeI n Θα
ζn = n⋅k⋅d⋅cos(Θ) for n= 0, 1, 2, 3...
a0
a1
Attenuators Phase shifters
+
0α
1−Nα
1α
Wavefronts
Receiver
00
jE e ξ⋅
10
jE e ξ⋅
10
NjE e ξ −⋅
d
Θ
Radiating elements
Combiner
aN-1
Phase difference at n-th element
Sum-Signal
Example: Linear Dipole Array
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune Br
oads
ide Θ
0=90
°
Endfire Θ0=0°
Pattern changes during scanning
Applications for Steerable Antennas
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
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
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,
Liquid Crystal as Tunable Material for Microwave Applications
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
DC
RF
V
0
2( ) ( )rU Uπβ ελ
Φ = ⋅ = ⋅
( ) ' '( ) ( )U U Uj L Cγ ω µ ε≈ ∝ ⋅
0
2( ) ) ( )0(r rU Uπ ε ελ
∆Φ = − ⋅
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)
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 on 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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Planar Antennas
Planar Phased Array Antennas based on Liquid Crystal Technology
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
Planar Phased Array Antennas based on Liquid Crystal Technology
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
@ 17.5 GHz
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)
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
Planar Phased Array Antennas based on BST Thick Film Technology
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
Planar Phased Array Antennas based on BST Thick Film Technology
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
Phase Shifters for Differential Signals
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Tunable differential phase shifter
Phase Shifters for Differential Signals
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Performance @ 10 GHz Phase shift = 225° FoM = 38°/dB
Insertion loss = -12dB Leakage current < 0.2 nA
@ 10 GHz
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
Volumetric Antennas
Tunable Antennas for Inter-Satellite Communications
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Tunable Antennas for Inter-Satellite Communications
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Tunable Antennas for Inter-Satellite Communications
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
-20-15-10-50
26 28 30 32 34 36 38 40
|S| [
dB]
050
100150200
26 28 30 32 34 36 38 40f [GHz]
FoM
| [°/
dB]
100225350475600
∆Φ
[°]
Tunable Antennas based on LTCC
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Reflectarray Antennas
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1
k0 Rn r n r 0 n 2 Nn
1
2
Functional principle Energy radiated by the feed Reradiated and phase-adjusted at
each element
Phase compensation
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
Reflectarray Antennas
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
Gain: 20.3 dB Directivity: 24 dB Efficiency: 42%
Reflectarray Antennas
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
Gain: 20.3 dB Directivity: 24 dB Efficiency: 42%
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
Impedance Tuning
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
FFDA
DA
HPA
LNA
VCODSP Φ
Baseband (software) reconfiguration for multi-standard operation Reconfigurable RF frontends with reconfigurable/tunable analog
RF components for multi-band (and multi-standard) operation
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
0 V
50 V
90 V Refle
ctio
n Co
effic
ient
(dB)
Frequency (GHz)
Equivalent Bandwidth
Tunable Dual-Band Antenna
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0
-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
0
-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
Application Example for Tunable Antennas
19.09.2012 | Institute of Microwave Engineering and Photonics | Holger Maune
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
Die
lect
ric L
osse
s
Frequency