Q-band Modulated Signal Segmentation Circuit CMOS IC Design

In order to meet the data processing speed and capacity requirements of the millimeter wave communication system,the power amplifier of the transceiver system must have high efficiency and high linearity at the same time.There are two types of predistortion: digital predistortion(DPD)and analog predistortion(APD).Compared with digital predistortion,analog predistortion has low power consumption and low energy consumption,so the research on millimeter wave adaptive linearization system is carried out around analog predistortion.According to the inflection point characteristics of the power amplifier: the degree of nonlinearity of the output signal is different at the inflection point of the gain curve,and the inflection point of the power amplifier is tracked through the segmental analog predistortion scheme to improve the nonlinearity of the power amplifier.The key circuits of amplitude segmentation are envelope detection circuit,comparison circuit and radio frequency switch circuit.The main work and contributions are:1.Through the two-stage peak detection circuit,the envelope detection of the modulated signal with a bandwidth of 800 MHz in the Q-band is realized,and the power consumption can reach 0.38 mW.The detected amplitude of the input signal is 50 m V-450 m V,and the output DC voltage range is 300 m V-680 m V.Compared with the detectors mentioned in other articles,the performance is better.2.Through the improved clockless comparator,the circuit design complexity brought by the clock generation circuit is reduced and the chip design cost is reduced.The input common-mode range of the comparator is 300 m V-700 m V,the propagation delay is 200 ps,the power consumption is 0.2 mW,and the detection accuracy is 80 m V.3.In order to improve the isolation degree of the switch,a series-parallel seriesparallel structure is adopted,which avoids the leakage of the signal when the switch is turned off,that is,the mutual interference of the three-way switch.The insertion loss S21 of the switch is-3.06 d B,the return loss is-10.8 d B,the isolation is-66 d B,and the switch on-off time is 150 ps.4.Based on three key circuits,the design and implementation of the 40 GHz,800 MHz modulation signal amplitude segmented CMOS IC in the Q-band is completed.Two-stage and three-stage amplitude segmentation schemes are designed for single inflection point and multi-inflection point,respectively.In the two-stage amplitude segmentation scheme,the segmentation errors in the two amplitude ranges are 6.5% and9.2%,respectively,and the overall error is 7.8%.In the three-stage amplitude segmentation scheme,the segmentation errors in the three amplitude ranges are 6.3%,8.4%,and 9.8%,respectively,and the overall error is 8.2%.The power consumption of two-stage and three-stage circuits does not exceed 5 mW.The chip area of the twosegment and three-segment circuit in this thesis is 420 um×450 um and 670 um×500 um respectively.