Design Of Key Modules Of Multi-band Wireless Receiver

The wireless receiver chip is an important part of the Internet of Things wireless communication system.Wireless receivers with multiple frequency bands can adapt to complex Internet of Things application scenarios.The main work of this thesis is to design the key modules of wireless receivers with multi-bands in smart meter reading and smart cities.Implimented by 0.18μm CMOS technology,low noise amplifier,down-conversion mixer and complex band-pass filter are designed.Applied in the IEEE 802.15.4g physical layer standard,the receiver covers multiple frequency bands in the Sub-GHz in the IEEE 802.15.4g protocol,completing the index division of each key module.In this thesis,the structure and optimization technology of broadband LNA are analyzed in detail.Designed a broadband balun LNA with adjustable gain in two stages.Based on the CG-CS structure,capacitive cross-coupling and bulk-coupling technology are combined.The optimization effect of the two technologies on the gain and noise performance of the LNA are analyzed and verified.A down-conversion quadrature mixer with double-balanced active structure with current bleeding technology is adopted to optimize the performance.To realize the wideband RF front-end circuit,LNA and the mixer are completed in layout designing.The post-simulation results show that the broadband RF front-end consumers 6.94m A current from 1.2V DC supply from 400MHz to 960MHz,in high-gain mode with 28.6d B voltage gain,noise figure less than 6.6d B,and IIP₃ is-12.9 d Bm.In low gain mode,the voltage gain is 21.2d B and the noise figure is less than 7.83d B,and the IIP₃ is greater than-8d Bm.The designed single-ended broadband LNA achieved peak power gain of 20.6 d B with a 3d B bandwidth of 400～960 MHz,a noise figure of 1.5 d B and,while consumed 7.64m A current from a1.8 V supply.A single-ended broadband LNA chip is also designed,based on the parallel negative feedback common-source structure,combined with current-reuse and noise cancellation technology to achieve better noise and gain performance,the test results show that the minimum NF of the LNA is 2.31d B in 400～960MHz,power gain is 19.24d B.Working principle and realization method of the complex bandpass filter are analyzed,and a fourth-order Butterworth active RC complex bandpass filter are designed.The post-simulation results show that the designed complex band-pass filter consumes 6.12m A,the pass-band gain is 0.77d B,and the noise figure is 30.7d B under the power supply voltage of 1.2V.