Analysis of miniaturized 3 dB branch-line hybrid couplers using distributed MIM capacitors
✍ Scribed by Sung-Chan Jung; Renato Negra; Fadhel M. Ghannouchi
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 863 KB
- Volume
- 52
- Category
- Article
- ISSN
- 0895-2477
No coin nor oath required. For personal study only.
✦ Synopsis
The far-field radiation characteristics of the proposed antenna were also investigated. As can be seen in Figure 5, the measured results show that the radiation patterns (co-polar and cross-polar patterns) at 1.9 GHz, 2.1 GHz, and 2.3 GHz operating frequencies show an approximately similar general polarization planes and similar radiation patterns. The simulated and measured antenna gain in the broadside direction of the antenna is also illustrated in Figure 6. It is noted that the measured maximum and minimum gain are 3.5 and 2.5, respectively, while the variation of the gain over the operating frequency is 61.0 dBi. Both predicted and experimental gains are in close agreement.
5. Conclusions
The design and analysis of a low profile folded and slotted microstrip-type antenna for third generation mobile handsets was presented. By careful shaping of a slot and folded edges, it was possible to achieve a very large bandwidth for an antenna of this type (nearly 18%), while maintaining a compact size and appropriate radiation characteristics. The proposed antenna was simulated on a finite and infinite ground plane and two different impedance bandwidth behaviors were obtained. It was found that when the antenna was mounted on a finite ground plane, the plane resonates at a neighboring frequency to that of the antenna, and it is this which contributes to the bandwidth broadening. By contrast, with an infinite ground, the resultant resonance was eliminated and thus the bandwidth was decreased. This led to the conclusion of which it is necessary to utilize the whole metallic structure of the handset to obtain the required bandwidth.
REFERENCES