A Low-Power CMOS Power Amplifier for 3.1-10.6GHz MB-OFDM Ultra-wideband Systems

A novel and low power ultra-wideband power amplifier circuit for 3.1-10.6GHz is proposed. This circuit is based on the two stage circuits to achieve full frequency band and low power consumption. Current-reused technology is applied to improve the power gain in the whole frequency band and reduce the DC loss in the drive stage. Simultaneously, a forward-body-bias-structure is added to the substrate end of the transistor, and the low power consumption is obtained by reducing the supply voltage. The cascade structure is used to improve the level of output power in power stage. Furthermore, in order to cover the whole bandwidth of UWB system, the input matching uses the T-type impedance transformation network to realize the low quality factor. Meanwhile, the RC AC-feedback- network is employed to improve the gain flatness of whole frequency band in the input and output terminals. The simulation results shows that the power amplifier achieves the saturation output power of 8dBm, an output 1dB compression point of 4.3dBm, a power gain and gain flatness of 15 +/- 1dB, input and output reflection coefficients of below 6.5dB and -7.6dB respectively, while only consuming 14.4mW from a 0.9V power supply with a die area of 0.74x0.71 mm(2).