5b_08.dvi

Size: px

Start display at page:

Download "5b_08.dvi"

しょうこおおはし
5 years ago
Views:

1 , Circularly Polarized Patch Antennas Combining Different Shaped Linealy Polarized Elements Takanori NORO,, Yasuhiro KAZAMA, Masaharu TAKAHASHI, and Koichi ITO 1. GPS LAN 10% [1] Graduate School of Science and Technology, Chiba University, Chiba-shi, Japan Japan Radio Co., Ltd., Mitaka-shi, Japan Japan Aerospace Exploration Agency, Sagamihara-shi, Japan Research Center for Frontier Medical Engineering, Chiba University, Chiba-shi, Japan Graduate School of Engineering, Chiba University, Chibashi, Japan [2] 2 90 [3] 10% [4][6] [7][9] [4], [5] 0.5λ [6] % 2dB 90 G/T B Vol. J91 B No. 5 pp c

2 2008/5 Vol. J91 B No. 5 [7], [8] [10] [9] % [11] % 10% AL 1 1 AL 2 (Pcut) ε r=1 Ensemble [12] [11] (a) Top view (b) Side view 1 Fig. 1 Geometry of proposed circularly polarized patch antenna. 1 Table 1 Fundamental antenna parameters. Length and width of excited patch AL 1 89 mm Length and width of parasitic patch AL 2 73 mm Chamfered depth Pcut 35 mm Distance between excited patch and GND TL 8mm Distance between excited and parasitic patch TH 10 mm 596

(a) Top view (b) Side view 2 Fig. 2 Geometry of conventional corner-truncated patch antenna. 2 2 I 1I 2 I 1I 2 f 1 f 2f 1f 2 f o f 2 f 1 /f o Q f o Q Q 2050 25% 2 1 (TL = 8 mm) 1.6 GHz Q 10 ΔS/S Q =0.

3 (a) Top view (b) Side view 2 Fig. 2 Geometry of conventional corner-truncated patch antenna. 2 2 I 1I 2 I 1I 2 f 1 f 2f 1f 2 f o f 2 f 1 /f o Q f o Q Q % 2 1 (TL = 8 mm) 1.6 GHz Q 10 ΔS/S Q =0.5 ΔS/S =5% [11] ΔS/S =15.5% Fig. 3 Calculated frequency response of axial ratio dB 12% 1.55 GHz (f alower ) 1.66 GHz (f aupper) 1.6 GHz (f acenter) 0.17 db0.20 db f alower f aupper f acenter GHz 1.46 GHz1.98 GHz 30% 597

4 2008/5 Vol. J91 B No. 5 (a) t =0 (b)t = T/4 4 Fig. 4 Frequency response of return loss. (excited patch only) (c) t = T/2 (d) t =3T/4 6 Fig. 6 Time variation of currents on excited patch. (excited patch only) (a) Frequency: 1.46 GHz (b) Frequency: 1.55 GHz (c) Frequency: 1.60 GHz (d) Frequency: 1.66 GHz (e) Frequency: 1.76 GHz (f) Frequency: 1.98 GHz 5 Fig. 5 Current distributions on excited patch. (excited patch only) GHz1.98 GHz GHz 1.66 GHz 1.6 GHz 1.66 GHz 1.98 GHz 1.76 GHz 5(a) (f) 1.46 GHz 1.98 GHz 1.46 GHz 2 I GHz I 2 5(b)(e) (b)(d) 1.6 GHz GHz 11 db I 1 I 4 [11] P 1 598

5 7 Fig. 7 Schematic of currents on proposed patch antenna. (a) Amplitude (a) Amplitude (b) Phase difference 9 P1P2 I1-I4 Fig. 9 Calculated frequency response of current I1-I4 at observation point P1 and P2. (b) Phase difference 8 P1 I1I2 Fig. 8 Calculated frequency response of current I1, I2 at observation point P1. P 2 P (a) I 2 8(a) I 1 f 1 =1.44 GHz I 2 f 2 =1.9GHz f 1 f I GHz I GHz I 1 8(b) I 1 I 2 3 3dB GHz 150 TH 9 8 9(a) I 2 I 1 I 4 7 I GHz 1.7 GHz I GHz 2.1 GHz I 1 I 2 I GHz I 1I GHz I 1 I

6 2008/5 Vol. J91 B No t Fig. 10 Loci of elliptical waves radiated from excited and parasitic patch and of their superposition. I 3 I GHz I GHz I 3 I GHz I 3 I P1 I 1I 2 P2 I 3I 4 9 P GHz db 4.4 db P2 P1 βth 3 11 Fig. 11 Schematic of currents on proposed patch antenna. 11 I ai b I ci d I ci d I ai b 9(a) I 1I 2 I ci d I 3I 4 I a I b I a I b I ci d I ci d I ci d I ci d (I a + I c)(i b + I d) 7 I 1 (I a + I c) 1.44 GHz 1.7 GHz I 2 (I b + I d) 1.7 GHz 1.9 GHz 2.1 GHz 1.7 GHz (I a + I c) I a I b I c I d I ci d 600

I a I c I b I d f a f b f a >f b 2(f a f b )/(f a + f b ) 9 I 1 I 3 C 13I 2 I 4 C 24 C 13 =0.19C 24 =0.21 I 1 I 2 I 3( C 13I 1) I 4( C 24I 2) I a I c I b I d 5. 12 2 2 1 0.5 mm 200 mm 12 Fig.

7 I a I c I b I d f a f b f a >f b 2(f a f b )/(f a + f b ) 9 I 1 I 3 C 13I 2 I 4 C 24 C 13 =0.19C 24 =0.21 I 1 I 2 I 3( C 13I 1) I 4( C 24I 2) I a I c I b I d mm 200 mm 12 Fig. 12 Photograph of fabricated antenna. 2 Table 2 Fabricated antenna parameters. Length and width of excited patch AL 1 87 mm Length and width of parasitic patch AL 2 71 mm Chamfered depth Pcut 35 mm Distance between excite patch and GND TL 8mm Distance between excite and parasitic patch TH 10 mm 13 VSWR Fig. 13 Measured and simulated VSWR. VSWR GHz VSWR GHz VSWR 601

8 2008/5 Vol. J91 B No. 5 (a) Measured and simulated gain (a) φ =0 (b) Measured and simulated axial ratio 14 Fig. 14 Measured and simulated antenna gain and axial ratio. 14 3dB8.9 dbi 1.66 GHz φ =0 φ =90 15 θ = θ =0 3dB φ =0 59 φ =90 60 φ =0 67 φ = dB φ =0 96 φ =90 71 φ =0 109 φ = dB 3dB (b) φ =90 15 Fig. 15 Measured and simulated radiation patterns % 3dB 602

9 [1] ( Fleet F77 Maritime Satellite Communication Terminal. [2] J.D. Kraus, Antennas, McGraw-Hill, N.Y., [3] J.Q. Howel, Microstrip antennas, IEEE Trans. Antennas Propag., vol.ap-23, no.1, pp.90 93, Jan [4] 4 Bvol.J65-B, no.10, pp , Oct [5] H. Nakano, H. Tanaka, T. Honma, H. Mimaki, and J. Yamaguchi, Low-profile helical array antenna fed from a radial waveguide, IEEE Trans. Antennas Propag., vol.40, no.3, pp , March [6] Bvol.J68-B, no.4, pp , April [7] A P81-102, Nov [8] T. Teshirogi, M. Tanaka, and W. Chujo, Wideband circularly polarized array antennas with sequential rotations and phase shift of elements, Proc. Int. Symp. on Antennas and Propagat., vol.i, pp , Japan, Aug [9] 2 Bvol.J65-B, no.2, pp , Feb [10] J.R. James and P.S. Hall, eds., Handbook of microstrip antennas, Peter Peregrinus, Ltd., London, [11] Bvol.J63-B, no.6, pp , June [12] Ansoft, Ansoft Ensemble user s Manual. A 1 TL Fig. A 1 Simulated axial ratio vs. spacing between excited patch and ground plane, TL. A 2 TH Fig. A 2 Simulated axial ratio vs. spacing between excited patch and parasitic patch, TH. 1 A 1 A 5 1 TL f alower 2 TH f aupper 3 Pcut f acenter 4 AL 1 A 3 Pcut Fig. A 3 Simulated axial ratio vs. chamfered length of excited patch, Pcut. 5 AL 2 603

10 2008/5 Vol. J91 B No IEEE A 4 AL 2 (AL 1 = 89 mm) Fig.A 4 Simulated axial ratio vs. length and width of parasitic patch, AL 2 (AL 1 = 89 mm) RLSA IEEE A 5 AL 2 (AL 1 = 95 mm) Fig.A 5 Simulated axial ratio vs. length and width of parasitic patch AL 2 (AL 1 = 95 mm). A 1 A IEEE AP-S Distinguished Lecturer AdCom IEEE FellowAAAS IEEE 604

untitled

untitled ( ) (mm) (GHz)=300( ) 30 300GHz=1 10mm ( 2GHz2Mbps) Gbps= Mbps ( m),? S G=P/Pi30dB=1000 Gm=4πS/λ 2, S= 80λ 2 Gm=30dB η=g/gm, S= 80λ 2,G=27dB η=50% (GHz) 80 70 60 50 40 30 20 10 16 19 22 25 28 31 34 37