This thesis is divided into two parts. In the first part, the antenna is integrated into the stacked package. The antenna and the semiconductor chip are co-designed together. We utilize the advantage of IPD manufacturing to develop strong capacitively coupled-fed miniaturization technology and fractal slots miniaturization technology. We design a miniaturized antenna operating at WLAN 2.4GHz band. The size of the antenna is only 4 mm¡Ñ8.625 mm (0.0327£f¡Ñ0.0707£f). The operating bandwidth is over 100 MHz. The radiation efficiency is over 60%. In the second part, we design a stacked structure using FR4 substrate. The MIMO antenna is miniaturized by strong capacitively coupled-fed miniaturization technique, and we propose an S-shaped isolator which has wider isolation bandwidth to improve the isolation problem. The separation of both antennas is only 12 mm. The size of the isolator is only 10 mm¡Ñ10 mm. The measured operating bandwidth is 200 MHz, and the radiation efficiency is over 60%. We also design a 10 mm¡Ñ10 mm size of MIMO antenna with 2 mm¡Ñ8 mm isolator on the stacked package structure. The antenna is operating at WLAN 2.45 GHz band, and the operating bandwidth is over 100 MHz. the radiation efficiency is over 40%. Finally, we propose two different stacked package antenna applications. The first one is a dual-frequency design. The proposed antenna is operating at GPS (1.57 GHz) band and WLAN 2.4 GHz band. Another is a broadband design. The size of IPD is only 3 mm¡Ñ3 mm. The operating bandwidth is 40% (from 4.8 GHz to 7.2 GHz).