To Build Up A Wireless and Seamless World
An Inverted-L Antenna Based on Finite Ground Plane with Zigzag Structure (Paper Accepted)
January 2010 – July 2010
Research Assistant, CMRFT in Shanghai Jiao Tong University, Shanghai, China
Advisor: Dr. Bin Yuan
Motivation: Small-size and light-weight are the development trends of future cell phone. However, with the reduction in size, the ground became smaller, and the distance between antenna and ground became closer, which brings in the finite ground plane (FGP) effect that may undermine the performance of the antenna in cell phone. So the goal of this research is to study the FGP effect quantatively and to solve the problem.
Outcomes:
- Measured the FGP effect on the performance of inverted-L antenna in cell phone quantitatively by both simulation and measuring in reality.
Inverted-L antenna's immunity to the FGP has been tested. Clearly, with the distance between the antenna and the FGP and the size of the FGP decrease, the impedance match condition deteriorates. This is mainly due to the fact that as the ground plane becomes smaller, the image of the inverted-L becomes incomplete, which subsequetly influence the performance significantly.
- Designed a novel inverted-L antenna with a zigzag structure to compensate for the loss due to the FGP effect.
Since the bad performance is caused by the incomplete image, a complementary method can be employed to solve this problem. A piece of antenna is attached to the other end of the ground plane to complete the image. The ultilization of the zigzag antenna is because of its small size.
- Validated the efficiency of the new antenna through simulation and fabrication.
The impedance match condition get remarkably improvement in our proposed structure. The impedance bandwidth of the antenna become 3 times wider than the traditional one. Meanwhile, the radiation pattern, which maintain a good omnidirectional pattern, does not change too much comparing to the original one.
- Submitted a paper to the 2010 Asia-Pacific Microwave Conference, and the paper was accepted (An Inverted-L Antenna Based on Finite Ground Plane with Zigzag.pdf (272,9 kB))
