Design And Application The Dynamic Power Supply And Bias Control Based On RF Linear Power Amplifier

In 3G communication, we usually use the less efficient linear power amplifier to make the final signal amplification, which affected cell phone battery life. By studying the basic principles of the amplifier, we find that adjusting the supply voltage and bias current of the amplifier can adjust the position of the operating point, and then achieve the purpose of improving the efficiency of the amplifier, while ensuring the signal without distortion. Design voltage regulator circuit using more efficient switched inductor converter.The study based on the original maturity of WCDMA mobile phone project, and modified some part of RF circuit. System uses MTK6268 platform, RF power amplifier is SKYWORKS the SKY77173. From the cost, performance, size and other aspects to consider, we select the PAM Company PAM2304 to design the voltage regulator circuit. System based on the different output of the power detector control two ADC output different voltages, to dynamically control the power amplifier supply voltage and bias reference voltage. By sub-section calculation and testing to complete the various parts of the actual circuit, finally completed the design of the entire system, and then change the phone board.Finally, in accordance with the WCDMA specification, test the performance of the phone board completely. Two parameters of the linear performance, ACLR and EVM are slightly worse, but can meet the specifications. When output power are 7dBm and 16dBm, with dynamic supply and bias control mode, the efficiency are 13.44% and 20.28%, compared with fixed supply and bias mode of 0.85% and 4.9%, increase significantly. Next, design the power calibration process, and authenticate system efficiency improvements using calibrated mobile phone. Calculate the actual average total power. Calculate the battery life in accordance with 4000mWh battery capacity. With dynamic supply and bias control PA, the battery life of the mobile phone will last for 61 hours as twice as the original state, 30 hours. We achieve the design goal.