Ultra-low power transceiver design is proposed for wireless sensor node used in the wireless sensor network (WSN).Typically,each sensor node contains a transceiver so it is required that both hardware and software designs of WSN node must take care of energy consumption during all modes of operation including active/sleep modes so that the operational life of each node can be increased in order to increase the lifetime of network.The current declared size of the wireless sensor node is of millimeter order,excluding the power source and crystal oscillator.We have proposed a new 2.4 GHz transceiver that has five blocks namely XO,PLL,PA,LNA and IF.The proposed transceiver incorporates less number of low-drop outs (LDOs) regulators.The size of the transceiver is reduced by decreasing the area of beneficiary components up to 0.41 mm2 of core area in such a way that some functions are optimally distributed among other components.The proposed design is smaller in size and consumes less power,＜ 1 mW,compared to other transceivers.The operating voltage has also been reduced to 1 V.This transceiver is most efficient and will be fruitful for the wireless networks as it has been designed by considering modem requirements.