Design Of Low Power Transmitter RF Front-end

The ultra-low power transceiver used in the Internet of Things is a research hotspot in the industrial and academic circles in recent years.Bluetooth low energy is currently popular short-range Internet of Things communication standard.In the short-distance transceiver system,the performance of the transmitter frontend has the greatest impact on the performance of the entire transmitter.It is of great significance to realize a high-performance low-voltage low-power RF transmitter front-end.In order to meet the requirements of high linearity,high port isolation and high efficiency of the RF transmitter front-end at low supply voltage,the traditional RF transmit front-end structure was improved in this thesis.The RF transmitter front-end includes an up-conversion mixer and a power amplifier.The Gilbert cell up-conversion mixer utilizes negative feedback technology and a folded transconductance stage structure was designed,it reduced the number of vertically stacked transistors in the circuit,so that the circuit can still maintain high linearity near the threshold power supply voltage;the switching stage is optimized by constructing a high-pass filter at the intermediate frequency input port,it reduces high-frequency glitches in the circuit and improves the port isolation of the circuit.A class-D power amplifier incorporates a low-loss differential to single-ended circuit to improve the circuit's work efficiency and integration and the reasons for the power loss in the class-D power amplifier circuit are summarized.Based on the TSMC 40 nm process,the circuit design,layout design and tape verification of the transmitter front-end were carried.Measurement results show that the peak output power of the Bluetooth low energy chip is 2.05 d Bm and the power consumption is 18.2m W.The post-layout simulation results of the up-conversion mixer show that under 0.7V supply voltage,the power consumption is only 0.7m W,the conversion gain is 0d B,and the IIP3 reaches 11.77 d Bm;the post-layout simulation results of the power amplifier show that under 1.2V supply voltage,the maximum output power is 6.33 d Bm,the power additional efficiency reaches 40.2%.