Parallel Hybrid Supply Modulators for 4G LTE-A RF Power Amplifiers

• Main Authors: Shui-Chang Cai, 蔡水長
• Other Authors: Jiann-Jong Chen
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/5f7mxb

碩士 === 國立臺北科技大學 === 電子工程系碩士班（碩士在職專班） === 104 === The thesis proposes a supply modulator for the envelope tracking radio frequency power amplifier (RF-PA). A high data transmission rate and a complex modulation technique lead to a high peak-to-average power ratio (PAPR). To improve the low efficiency of RF-PA because of the high PAPR, the envelope tracking technique modulates the supply voltage to drive the RF-PA. In order to increase the supply modulator efficiency and keep the output linearity, the architecture is composed of a linear amplifier and a switching amplifier with parallel connection. The first part of the thesis is a hybrid supply modulator composed of a rail to rail input and output linear amplifier and a switching circuit in parallel. The hybrid supply modulator maintains the output voltage and provides the power to the load. The duty cycle of the switching circuit is controlled by the sensing current from the linear amplifier output stage. Thus, the inductor current follows the load current. The hybrid supply modulator has been fabricated in TSMC 0.18 um process. The output range is 0.7 V~2.5 V, the maximum output current is 540 mA, and the chip area is 0.764 mm × 0.901 mm. The second part of the thesis is a parallel hybrid supply modulator with the control of dual bandwidth inputs. The control loops of the linear amplifier and the switching amplifier are independent to each other. The supply modulator has low switching losses and ground bounces caused by the switching amplifier. The proposed supply modulator has been fabricated in TSMC 0.18 um process. The output voltage is 1.1 V~2.9 V, the maximum output current is 725 mA, and the chip area is 1.2 mm × 1.2 mm.