1 Super-wideband Antenna Technologies for Next Generation Mobile Systems Student: Jianjun Liu Student ID: Supervisor:Karu. P. Esselle Centre for Microwave and Wireless Applications, Electronics Engineering, Macquarie University, NSW 2109, Australia

2 Outline Introduction Antenna requirement Antenna development and Case study Proposed extremely wideband antenna for wireless communication Systems Conclusion

3 Wireless Communication System dBm/MHz maximum power level for UWB

4 GPS (1.57–1.58 GHz) WCDMA (1.92–2.17 GHz) Bluetooth ( GHz) WLAN b/g ( ) WLAN802.11b/g ( ) Wi-max ( GHz) Commercial UWB (3.1–10.6 GHz) Vehicle UWB radar system(22-29GHz) Examples for existing communication standard

5 Examples for multi-band wireless system Cellar system (GSM, Bluetooth, CDMA, USMT)

6 Wireless Local Area Network

7 UWB through wall image operation (0-960MHz) Commercial UWB, localization precision(3.1–10.6 GHz) vehicle UWB radar system(22-29GHz)

8 Antenna Requirement Key component Antenna performance Proposal A: multiple antennas are implemented Each one covers a specific operation spectrum. Disadvantage: Occupy much space for other device Increase the system complexity. The installation may restrict the system updating possibility after manufacture. Proposal B: Utilize single antenna Antenna bandwidth can cover more than one operating frequency bands of multiple wireless communication systems Such antenna should have stable radiation-pattern characteristics over entire frequency range.

9 Lodge’s biconical antennas (1898) Carter’s improved match biconical antennas (1939) Antenna Development The antennas are bulky and too heavy for portable device

10 Equiangular spiral antenna (1959) log-periodic dipole antenna (1960) The movement of the effective radiating region with frequency results in waveform distortion of a transmitted pulse

11 Metal-plate Monopole Antennas Ratio impedance bandwidth: 13:1 Frequency range : GHz J.A. Evans and M.J. Ammann. “Planar trapezoidal and pentagonal monopoles with impedance bandwidths in excess of 10:1 [C],” IEEE Antennas Propagat. Symp., vol.3, pp , July, 1999.

12 Frequency range : GHz Ratio Impedance bandwidth: 8.3:1 The perpendicular ground plane leads to antennas with high profiles which is inconvenience for integrating with monolithic microwave integrated circuits (MMIC). Kin-Lu Wong, Chih-Hsien Wu, and Saou-Wen Su, “Ultrawide-Band Square Planar Metal-Plate Monopole Antenna With a Trident-Shaped Feeding Strip, ” IEEE Trans. Antennas Propagation, vol.53, pp , April, 2005.

13 Microstrip-feed Printed Monopole Antenna J. Liang, Choo C. Chiau, X.D. Chen, et al. “Study of a Printed Circular Disc Monopole Antenna for UWB Systems” [J].IEEE Trans. Antennas Propag., 2005, 53(11): Impedance bandwidth ratio : 3.52:1 Frequency range : GHz

14 CPW-fed Printed Monopole Antennas Impedance bandwidth ratio : 4.4:1 Frequency range : GHz J. Liang, L. Guo, C.C. Chiau, X. Chen and C.G. Parini. Study of CPW-fed circular discmonopole antenna for ultra wideband applications[J].IEE Proc.-Microw. Antennas Propag.,2005,152(6):

15 Disc Elliptical patch Discone Trapezoid ground plane Coaxial-feeding line CPW feeding line Complanation Transform from Discone Antenna

16 S.-S. Zhong, X.-L. Liang and W. Wang, “Compact elliptical monopole antenna with impedance bandwidth in excess of 21:1,”IEEE Trans. Antennas Propagation, vol.55, pp , November, Performance for antenna with Trapezoid Ground Plane

17 tapered trapeziform Elliptical Performance Comparison between different printed antenna

18 Characteristic Mode Analysis for Printed Antenna K. D. Akkerman, T. F. Kennedy, S. A. Long, and J. T. Williams, "Characteristic modes for planar structure feed design," in Antennas and Propagation Society International Symposium, 2005 IEEE, 2005, pp vol. 2B.

19 Characteristic Mode Analysis for Printed Antenna

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21 Modified Coplanar waveguide-fed elliptical monopole The feeding terminal affect the high frequency impedance matching

22 With height and width of patch increased, the lowest limit decrease and ratio bandwidth increase Width a （ mm ） b=30mm Ratio bandwidth VSWR≤2 Impedance bandwidth (GHz) VSWR≤2 a= : a=120 53: Height b （ mm ） a=120mm Ratio bandwidth VSWR≤2 Impedance bandwidth (GHz) VSWR≤2 b=30 53: b=90 64: Modified Coplanar waveguide-fed elliptical monopole

23 Modified Coplanar waveguide-fed elliptical monopole Gap is a crucial parameter, The gap variation will affect the impedance bandwidth of whole spectrum

24 Substrate: Rogers permitivity:3.48 ， thickness:1.5mm 。 D max H a b Measured bandwidth: GHz, ratio bandwidth:23:1 Modified Coplanar waveguide-fed elliptical monopole

25 (a) (b) (c) (d) (a)f=1.5GHz (b) f=5GHz (c) f=10GHz (d) f=20GHz Maximum gain: 7.2dB Gain decrease ： 1 substrate loss 2 radiation shifting Smith chart Modified Coplanar waveguide-fed elliptical monopole With the frequency increasing, cross polarization increased. Reverse current lead to pattern distortion and horizontal current lead to cross polarization enhanced.

26 Modified Microstrip-fed printed monopole Based on modified CPW-fed printed monopole, two modified microstrip-fed monopole are proposed

27 Antenna type Ratio bandwidth VSWR≤2 bandwidth (GHz) VSWR≤2 Ordinary antenna20:10.47 – 9.8 Proposed antenna59: Modified Microstrip-fed printed monopole

28 Measured bandwidth: GHz, ratio bandwidth:25:1 Top side Modified Microstrip-fed printed monopole Back side

29 E Plane H Plane (a)f=1.5GHz (b) f=5GHz (c) f=10GHz (b)(d) f=15GHz(e) f=20GHz Modified Microstrip-fed printed monopole

30 Modified Microstrip-fed printed monopole Maximum gain: 6.5 dB Gain variation between 4-20 GHz: 2.5 Db

31 Original proposed antenna Measured bandwidth: GHz Modified Microstrip-fed printed monopole

32 ordinarytaperedproposed Bandwidth (GHz) VSWR≤ Ratio bandwidth Input impedance （ Ω ） Modified Microstrip-fed printed monopole

33 Measured bandwidth: GHz, ratio bandwidth:46:1 Modified Microstrip-fed printed monopole Top side Back side

34 E Plane H Plane (a)f=1.5GHz (b) f=5GHz (c) f=10GHz (b)(d) f=15GHz(e) f=20GHz Radiation shifting is small Modified Microstrip-fed printed monopole

35 Maximum gain: 8.3dB, gain increases in the whole spectrum Modified Microstrip-fed printed monopole

36 Conclusion Three new configuration of monopole antenna for wireless applications Four Techniques can enhance BW: 1 tapered Microstrip-feeding line 2 trapezoid ground plane 3 optimized radiation patch 4 semicircular feeding branch terminal

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