Multiple antennas system is used to replace traditional single antenna circuitry in radio transceiver system in order to improve transmission capability and reliability. With multiple antennas, data transfer rate can be increased by a factor of n, where n is the number of antennas used in the transceiver. To avoid the uses of multiple RF chain associated with the multiple antennas, an antenna selection system, RF switch, is essential. The desired switching system must have a simple structure and low cost yet still can capture all the advantage of Multiple Input Multiple Output (MIMO) systems. In this paper, we propose a Double Pole Four Throw (DP4T) RF switch using Complementary Oxide Metal Semiconductor (CMOS) technology. This switch is low in cost, and capable of selecting data streams to or from the two antennas for transmitting or receiving processes, respectively. Since the operating frequencies of the switch are 2.4 GHz and 5.0 GHz, it is useful in Wireless Local Area Network (WLAN) and other IEEE 802.11 applications. Our DP4T CMOS Switch exhibits insertion losses of 0.7456 dB and 0.8550 dB for 2.4 and 5.0 GHz, respectively, with a 1dB compression point of 31.86 dBm. Furthermore, our switch also experience minimal distortion, negligible voltage fluctuation, and low power supply of only 1.2 V.