100. 100. 10. 4. 3 vodljiva ravnina. 100. 100. 2,8. Ref: D. BonefaÄiÄ, et. al. Frequenz 2007. Ref: D. BonefaÄiÄ, J. BartoliÄ, ICECom 2010, Dubrovnik ...
Overview of Innovative Antenna Research at the University of Zagreb Juraj Bartolić
University of Zagreb Facultyy of Electrical Engineering g g and Computing p g Department of Wireless Communications
Antenna A R & D at the h U University i i off Z Zagreb b focus on
Miniaturisation
Small antennas
Broadbanding oadba d g Multiband antennas
UWB antennas Hardware d i design Reconfigurable antennas G1DMULT algorithm AIA &RFID
Conformal antennas
Optimization algorithms
Software design
Motivation • • • • • • • •
Antennas A t for f mobile bil tterminals i l Antennas for conventional base stations Antennas for UWB communications Reconfigurable f antennas for f base station and small terminal antennas Reconfigurable antennas for satellite communications RFID antennas Sensor antennas Active integrated antennas (AIA)
Outline • Small S ll antennas t (l (low profile fil antennas) t ) – Miniaturizing techniques – Broadbending techniques
• Antennas for UWB communications – Interference problem inside UWB range – Band rejection techniques
• • • •
Conformal antennas Active integrated and RFID antennas R Reconfigurable fi bl antennas t Software design g
Small Antennas
Small antennas Miniaturization techniques W
The first step: half the patch length ! W
patch
L≈ λ/2 via
L≈ λ/4
Small antennas Miniaturization techniques B
A 50 9,8
22,8
50
5 25
8,8 5
7
25 8,8
vodljiva ravnina
100
vodljiva ravnina
100
100
100
C
4,2 5
D
30
3,7 5
4,5
10
5
3,9
2,4
30
3,7
10
2,8
4
3
100
vodljiva ravnina
100
10 100 vodljiva ravnina
100
Ref: D. Bonefačić, et. al. Frequenz 2007 Ref: D. Bonefačić, J. Bartolić, ICECom 2010, Dubrovnik
Small antennas Miniaturization techniques 1
2
Sloped Coupled Patch 9,5 50 8
W
L
7
100
H d
h
Feed
50
8
7,5
31 6
5
Driven Patch
0 Ground Plane
Short Circuit
-5
Measured VSWR S 11 [dB ]
-10 -15
S11 [dB] -20 -25
PIFA PIFA PIFA + hand PIFA + hand PIFA + hand + head PIFA + hand + head
-30 30 -35 -40 850
Ref: D. Bonefačić, J. Bartolić, ICECom 2010, Dubrovnik
900
950
Frequency [MHz] Frequency [MHz]
1000
Ultra Wideband (UWB) Antennas
Interference problem in UWB systems
S lf Self-complementary l t antenna t Ö Development of a compact wide-band antenna g mount base stations for ceiling Self-complementary antenna
Self-complementary monopole
Arraying of two triangular monopoles ANTENNA 1
Za=188 Ω Za=94 Ω ground plane
Ref. J. Bartolić et al., APS 2007, Hawaii, Honolulu
Za=47 47 Ω
UWB antenna of two bow-tie monopoles
d2=74.5
d1=25.5
Ref. J. Bartolić et al., Frequenz 2007.
UWB antenna of two bow-tie bow tie monopoles |S11 |
0
[dB] 5
Z0=100Ω VSWR=2
10
1
VSWR=2 15
5 5
Z0=50Ω 20
25
30 0.5
1
1.5
2
2.5
3
3.5
Frequency [ GHz] 0 5 GHz 0.5
array (normalising impedance: Z0=50Ω) single (normalising impedance: Z0=100Ω)
Ref. J. Bartolić et al., Frequenz 2007.
4
4.5
5
Comparison of experimental results for modified antenna 90 120
90 1.0
60
60
E-plane
0.8
–10 10 dB
H-plane 150
0.6
30 –20 dB
30
0.4 0.2
–30 dB
180
0
1 GHz 3 GHz 5 GHz
210
240
0
330
64.3
100
feed
300 270
300 270
triangular l monopole grounded plate 300 64.3 grounded plate
330
1 GHz 3 GHz 5 GHz
80 38.3
type-N connector
Planar noched UWB antennas Dual band 17 5 17.5 1
1
35 4 35.4 ground plane
2
coaxial feed
17.5 1
0 25 0.25
14 0 25 0.25
6.7
10
1
0.5
0.5
11.4 29.3 20.4
29.3
ground plane
ground plane
2
coaxial feed
2
coaxial feed
Ref: M. Banožić, et al., IWAT 2010, Lisbon
Active Integrated Antennas (AIA) AIA)
Constructing Elements for AIA Planar antennas Passive components
Active devices Schottky diode: mixer, multiplier varactor diode: tuning, VCO
power combiner/divider hybrids
Gunn device: mmw oscillator FET, HEMT, HBT: oscillator, ill t amplifier, lifi etc. t
transmission lines: (MS, CPW, SL, etc)
MEMS
filters, resonators MEMS
Compact self self-oscillating oscillating U U-patch patch AIA Circuit layout
Base R2 R1
E
Line Transformer
–Vdc
Collector Vias
Chip Capacitor
Ref: D. Bonefačić, J. Bartolić, AP-S 1999, Orlando
C Compact t self-oscillating lf ill ti push-pull h ll AIA Circuit layout
Base
E
Coupling Li Line Collector E
Collector Rstab
Base
–Vdc
Chip Capacitor
Ref: D. Bonefačić, J. Bartolić, EuMC 2000, Paris
S lf Self-oscillating ill ti push-pull h ll AIA Active circuit +Vdc d
coupling line RB C
∆fB≈180 ≈180°
RB C
T1
T2
output 1
L
Rstab
Rstab
∆fE≈180°
output 2
L
RE
–Vdc
T1 and T2 NPN bipolar transistors AT-41485
Reconfigurable Antennas
Slot antennas with frequency band switching g or changing g g PIN diode or MEMS or varactor diodes
0
0 -5
-5
-10 -10
S11 (d dB)
S11 (dB)
-15 -20 -25 -30
-15
-20
measurement calculation
-25
-35 measurement calculation
-40 -45 0.5
1
1.5
2
2.5
-30
3
-35 0.5
1
Frequency (GHz)
Ref: T. Debogović et al., MRRS-2008, Kijev, Ukraine
1.5
2
Frequency (GHz)
2.5
3
Reconfigurable antennas Radiation pattern reconfiguration
Ref: T. Debogović, J. Bartolić, IEEE MTT-S International Microwave Workshop Series on Wireless Sensing, Local Positioning, and RFID, Cavtat, Croatia, 2009
Reconfigurable antennas Polarization reconfiguration
Ref: T. Debogovic and J. Bartolic, EuCAP 2010, Barcelona, Spain
Reconfigurable antennas Partially Reflective Surface (PRS) Antenna with Dynamic Beamwidth Control 10 x 10 planar PRS array
Unit cell
Driving patch & reflector (PEC) Ref: T. Debogović et al., IEEE Antennas and Wireless Propagation Letters, 2010
Reconfigurable antennas PRS antenna for linear polarization measured results E-plane H-plane
circular polarization
Ref: T. Debogović et al., accepted for ESA workshop (Challenges for Space Antenna Systems), Noordwijk, NL, 18-21 October, 2011.
RFID Antennas
Size reduction of RFID antenna for cable identification application Prototypes
Ref: Tin Komljenović et al., EuCAP 2011, Rome
Conformal Antennas
Conformal antennas design g Spectral domain Green’s function algorithm G1DMULT h b has been applied li d ffor analyzing l i diff differentt ttypes off z conformal arrays and lense-antennas: θ h
ρGND
dz dφ
εr , tan δ
Ref: Z. Šipuš et al., IEE Proc. Microwave Antennas Propag., 2005.
References:: References D. Bonefačić,, J. Bartolić,, Overview of Small Antenna Research at the Universityy of Zagreb, g , Conference Proceedings g of 20th International Conference on Applied Electromagnetics and Communications(ICECom 2010), Dubrovnik, 20-23 Sept. 2010, pp. 1-8. M. Banožić, J. Bartolić, B. Ivšić, T. Debogović, Dual Band Planar Folded Monopole, 2010 International Workshop on Antenna Technology: Small Antennas Antennas, Innovative Structures and Materials (iWAT 2010), 2010) Lisbon Lisbon, Portugal Portugal, 1 1-3 3 March 2010, pp. 1-4. J. Bartolić, T. Debogović, M. Knežević, Ultra Wideband Antenna of Two Bow-Tie Monopoles, Frequenz, Vol. 61, No. 5, pp.106-109, 2007. D. Bonefačić, J. Bartolić, Design Considerations of an Active Integrated Antenna, Radioengineering, Vol. 14, No. 4, pp. 33-39, December 2005. T. Debogović, J. Bartolić, Pattern Reconfigurable Compact Antenna, Proceedings of IEEE MTT-S International p Series on Wireless Sensing, g, Local Positioning, g, and RFID,, Cavtat,, Sept. p 24–25,, 2009,, pp pp. 95-98. Microwave Workshop T. Debogović, J. Bartolić, Capacitively Fed Annular Ring Microstrip Antenna with Reconfigurable Circular Polarisation, Proceedings of 4th European Conference on Antennas and Propagation (EuCAP 2010), Barcelona, Spain, 12 – 16 April 2010, pp. 1-4 T Debogović, T. Debogović JJ. Perruisseau Perruisseau-Carrier, Carrier JJ. Bartolić Bartolić, Equivalent Surface Modelling for Reconfigurable Partially Reflective Surface Antennas, Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP 2011), Roma, Italy, 11- 15 April 2011, pp. 3660-3664. T. Debogović, J. Perruisseau-Carrier, J. Bartolić , Partially Reflective Surface Antenna with Dynamic Beamwidth Control, IEEE Antennas and Wireless Propagation Letters, Vol. 9, pp. 1157 – 1160, Dec. 10, 2010. T. Komljenović, Z. Šipuš, J. Bartolić, RFID Tag Antenna for Cable Identification Application, Proceedings of 20th International Conference on Applied Electromagnetics and Communications (ICECom 2010), Dubrovnik, 20-23 Sept. 2010,, pp. pp 1-4. T. Komljenović, Z. Šipuš, J. Bartolić, Size reduction of RFID antenna for cable identification application, Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP 2011). Roma, Italy, 11- 15 April 2011, pp. 415-418. N. Burum, Z. Šipuš, J. Bartolić, Mutual Coupling Between Spherical-Rectangular Microstrip Antennas, Microwave and Optical Technology Letters, Letters Vol. Vol 40 40, No No. 5 5, pp. pp 387-391, 387 391 March 5, 5 2004 2004. Z. Šipuš, M. Lanne, L. Josefsson, Moment Method Analysis of Circular Cylindrical Array of Waveguide Elements Covered with a Multilayer Radome, IEE Proceedings. Microwaves, antennas and propagation, Vol. 153, No. 1, 2006, pp. 29-37.
Thank you ! Acknowlegment: Some parts of this material have been supported by EU and US Air Force through FP7 and EOARD projects, like ACE Antenna Centre of Excellence (FP7) (FP7), and some results are outcomes from the EU COST Actions 223 223, 245 245, 260 260, 284, 284 and ASSIST (IC0603 Action), and EurAAP WG on Small Antennas