Design And Research Of Miniraturize WLAN Antenna

Currently, with the development of the wireless communication, the terminal equipments of personal communication are becoming smaller and smaller. Some methods of designing antennas are introduced in the paper. Base this, two antenna designing program are proposed. At first, we describe the antenna theory in the paper. Then, we use the Ansoft HFSS 11 to create the electromagnatic antenna model and analize the frenquency character,S11 and the radiation pattern. At last, we analize the effect of the substrate’s dielectric const and the antenna’s size.The first antenna applicate the technology of LTCC(Low temperature CO-fired ceramic).It is the layered ceramic chip antenna based on LTCC.The antenna use the mender line structure.The ceramic structure is divided into ten layers.The antenna’s metel structuer attached on the forth layer and the eighth layer.These two layers connect with each other by via-hole.It achieves the comunicate band of 2.4GHZ, 5.2GHZ and 5.8GHZ.The S11 of the antenna is less than -6dB.The bandwidth is relatively good,respectively 200MHZ and 600MHZ.The peak gain are 2.45dBi and 3.12 dBi.The second antenna is a typical microstrip antenna which use the substruct of menderline. It’s fed in the bottom of the antenna by coaxial.It use FR4 PCB bord as the test bord. Rogers’ 3010 model plate whose thickness is 0.5mm is used for the antenna to attach.This plate is characterized by high dielectric constant. It cut the size of the antenna effectively,but the price of the plate is relatively high.The cost is high if processing small quantities.The antenna working good in 2.4 GHZ and 5.2 GHZ.In the case of that the S11 of the antenna less than -6dB.In these two bands, the band width respectively 130 MHZ and 500 MHZ.Finaly,the antenna is processed out and tested.Obtained the data of the antenna. The thickness of the antennas are not more than lmm,the width are less than 7mm. Satisfy the requirement of low return loss,small size,good omni-directional.Because of the character of the small size and low planing surface.It can be installed in the small terminal equipment well.