With the rapid development of wireless communication technology, wireless communication terminals began to miniaturization and multi-direction. As wireless communications' import and export, antenna has a large affects on the performance of wireless communication systems. In most cases, the size of the wireless communication terminal is mainly determined by the size of the antenna.
This paper shows some methods for how to decrease the size of microstrip antenna. Especially, the method which is using the combination of parallel end-shorted coupled lines and capacitor is detail described. It is proven that antenna is fabricated with capacitive loading to reduce the resonant frequency of antenna, which is similar to reduce the size of antenna, and using parallel end-shorted coupled lines can also reduce the size of antenna. The antenna is fabricated on the FR4 epoxy glass cloth copper-clad PCB substrate having thickness 0.8mm and the dielectric constant is 4.4. The size of antenna is 28mm*14mm, and the center frequency is 1GHz. Simulated and measured results show that the return loss is greater than 15dB.