More Related Content
Similar to 2005 IEEE AP-S-Internal Shorted Patch Antenna for UMTS Mobile Phone
2005 IEEE AP-S-Internal Shorted Patch Antenna for UMTS Mobile Phone
- 1. 2005 IEEE AP-S International Symposium Internal Shorted Patch Antenna NSYSU for UMTS Mobile Phone *Saou-Wen Su1, Kin-Lu Wong1, C.L. Tang2, S.H. Yeh2 1 Dept. of Electrical Engineering National Sun Yat-Sen University Kaohsiung 80424, Taiwan 2 Computer & Communications Research Lab Industrial Technology Research Institute Hsinchu 31040, Taiwan *E-mail: susw@ema.ee.nsysu.edu.tw Jul 2005
- 2. Dept of EE,NSYSU, Taiwan NSYSU Outlines (I) Introduction Configuration of the conventional mobile-phone PIFAs Mobile-phone PIFAs with a shielding metal box (II) Design Considerations of the Antenna Constructed prototype of the internal patch Parametric studies on the impedance matching (III) Comparison of the Antenna Performance Between the proposed patch and the corresponding conventional PIFA Advantages over the conventional PIFA designs (IV) Conclusion 2
- 3. Dept of EE,NSYSU, Taiwan Conventional PIFAs (1)- NSYSU On the feeding/short-circuiting PIFAs Conventional PIFAs mainly comprise: a top patch, a feeding pin, and a shorting pin The top patch is usually mounted above a system ground plane; The shorting and feeding pins, connected to the top patch at proper positions, have the same length as the distance between the patch and the ground plane 3
- 4. Dept of EE,NSYSU, Taiwan Conventional PIFAs (2)- NSYSU Metal box placed away from the PIFAs Conventionally a large isolation distance (usually > 7 mm) is required between the internal PIFA and the RF/battery shielding box for avoiding destructive coupling MOTL, vol. 32, pp. 87-88, Jan 2002 MOTL, vol. 41, pp. 483-486, Jun 2004 4
- 5. Dept of EE,NSYSU, Taiwan Design Consideration (1)- NSYSU Configuration of the internal patch Detailed dimensions of the shorted patch; Design example for UMTS folder-type mobile phones TW/US Patent Pending 5
- 6. Dept of EE,NSYSU, Taiwan Design Consideration (2)- NSYSU Antenna return-loss performance 9.6-dB RL BW (2:1 VSWR) satisfies the UMTS band, 1920~2170 MHz Relatively small variations in the measured RL for three possible talk positions are seen The center frequency can be obtained from the following equation: c f≈ 4 × (0.5L + W ) where c is the speed of light 6
- 7. Dept of EE,NSYSU, Taiwan Design Consideration (3)- NSYSU Measured radiation patterns, peak gain Measurement is for the Measurement is for the talk position with α = 15oo talk position with α = 15 Peak antenna gain level reaches about 3.4 dBi across the UMTS band 7
- 8. Dept of EE,NSYSU, Taiwan Design Consideration (4)- NSYSU Parametric studies on impedance BW Other parameters are the Other parameters are the same as given previously same as given previously Increasing h in general increases the impedance BW; Feed gap d is inversely proportion to the center operating frequency 8
- 9. Dept of EE,NSYSU, Taiwan Design Consideration (5)- NSYSU Parametric studies on impedance BW (continued) Decreasing t leads to a slight decrease in the center operating frequency, different from a quick decrease in that of the conventional PIFA; Short-circuiting the patch to the antenna ground is to introduce additional inductance to compensate for the capacitive coupling between the patch and the bottom ground 9
- 10. Dept of EE,NSYSU, Taiwan Antennas by Comparison (1)- NSYSU On the surface current distributions Smaller surface current distributions are seen in the portion below the proposed antenna ground Proposed antenna should be less prone to hand effects on the performance degradation Conventional PIFA of size 28 x 15 mm2 (short-circuited by a pin) with h = 6 mm and t = 2.5 mm 10
- 11. Dept of EE,NSYSU, Taiwan Antennas by Comparison (2)- NSYSU Shorted patch with a shielding metal box Shielding metal box in vicinity to the antenna and the conventional PIFA with an isolation distance D Detailed Detailed 11
- 12. Dept of EE,NSYSU, Taiwan Antennas by Comparison (3)- NSYSU Effects of the metal box on impedance BW Impedance matching quickly degraded with a decrease in D Negligible variations on the impedance matching over the bandwidth 12
- 13. Dept of EE,NSYSU, Taiwan Antennas by Comparison (4)- NSYSU Radiation power contributed from antenna Proposed antenna and corresponding PIFA are divided into various portions for investigating each portion that contributes to radiation power Shorted patch Antenna ground Proposed antenna Proposed antenna Bottom ground Upper ground 13
- 14. Dept of EE,NSYSU, Taiwan Antennas by Comparison (5)- NSYSU Radiation power contributed from antenna (continued) Shorted patch Corresponding Corresponding conventional PIFA conventional PIFA Bottom ground Upper ground 14
- 15. Dept of EE,NSYSU, Taiwan Antennas by Comparison (6)- NSYSU Radiation power contributed from antenna Simulated (IE3D) antenna efficiency are normalized with respect to total antenna efficiency of 81% and 78% for the proposed antenna and the corresponding PIFA 15
- 16. Dept of EE,NSYSU, Taiwan Internal Shorted Patch for NSYSU UMTS Mobile Phone Application Other possible embodiments: For bar-type mobile phone application Proposed PIFA mounted at the bottom end of the bottom ground 16
- 17. Dept of EE,NSYSU, Taiwan Internal Patch Integrated with NSYSU Shielding Metal box UMTS antenna can also be integrated with a step-shaped shielding metal box served as an antenna ground plane More board space on the system circuit board are released for deploying the RF modules or other associated components UMTS antenna integrated with a step-shaped shielding metal box 17
- 18. Dept of EE,NSYSU, Taiwan NSYSU Conclusion Proposed shorted patch antenna can be arranged to be in close vicinity to the RF shielding metal box with small coupling effects between the antenna and the shielding metal box More designs of the internal mobile antenna integrated with the shielding metal box are foreseen and in progress 18
- 19. Dept of EE,NSYSU, Taiwan THANK YOU FOR YOUR ATTENTION! NSYSU 19