Adaptive antenna and phased array are powerful techniques in wireless communication. The phased array can transmit the signal to the preferred direction with the desired coverage. It introduces the concept of space division multiple access in addition to the CDMA, TDMA and FDMA. Additionally adaptive antenna can use the same arrangement of the antenna array to improve the SINR dramatically by spatially filtering out any interference. These two techniques are promising for introducing flexible and efficient algorithms for wireless sensor networks. This paper focuses on the structure implemented in the sensor node transceiver and uses the 4-element circular antenna array as an example. It also discusses what advantages these techniques provide in wireless sensor networks.