Research On Highly Integrated Silicon-based Amplitude Phase Control Multifunction Chip

As modern communication systems become more and more highly integrated and multifunctional,different system requirements have given rise to a variety of communication technology solutions.As one of the mainstream solutions,phased array system has been widely paid attention by academia and industry for its advantages of beam focusing and fast response,high environmental adaptability and high reliability.The amplitude phase control circuit,as one of the core modules,can quickly change the direction of the main beam and significantly improve the direction selection ability of the signal,which directly affects the sensitivity of the communication system.To solve the disadvantages of low integration,high power consumption and poor consistency of traditional discrete components amplitude phase control module,and to overcome the defects of compound semiconductor process which is difficult to realize digital-analog integration,it is important to study highly integrated silicon-based amplitude phase control multifunctional chip.In thesis,based on SMIC 55 nm CMOS process,the key functional modules in Kaband amplitude and phase control multifunction chip and K and Ka-band transmit frontend chip are studied in depth as follows:1.Passive phase shifter with attenuation compensation network and ultra-wideband low phase error phase shifter is studied.The former is based on the adaptive implementation of T-type,π-type and switch-type phase shift units to achieve different phase shift requirements,and qualitatively analyze the formation factors of phase shift additional attenuation,and use coherent synchronous coordinated attenuation compensation network to effectively improve the attenuation fluctuation in high phase shift state.simulation results in Ka-band show that the root mean square(RMS)error of phase shift is less than 1.8°,and the RMS phase shift additional attenuation error is within0.28 dB.The latter uses a switched LC-type structure to achieve accurate phase shifting in small layout size and a coplanar waveguide-based T-type structure to achieve large bit phase shift in wide band.20-38 GHz simulation results show that the reference state insertion loss is less than 6.8 dB and the input and output return loss is better than 10 dB.2.Switchable driver amplifier and ultra-wideband differential structure power amplifier are researched.Based on the three-stage common source structure and RC negative feedback technology to achieve high gain driver amplifier,combined with low dropout voltage regulator(LDO)enable control bias,to achieve the shutdown efficacy,reduce the power consumption of transceiver link and increase the isolation degree.The power amplifier uses a three-stage differential common-source pole structure,using onchip Barron to participate in matching to complete the impedance transformation under ultra-wideband to expand the bandwidth,and through the neutralization capacitor to improve the gain and stability of the amplifier.22-38 GHz simulation results show that:the small signal gain of the power amplifier is greater than 22 dB,and the output 1dB compression point is greater than 7dBm.3.Based on the existing modules and the above researches,we complete the optimization and integration of the Ka-band amplitude and phase control multifunctional chip link.In the existing layout,the original chip is replaced by a phase shifter with attenuation compensation network to obtain high-precision phase control,and all DCpowered PADs are unified to simplify the control logic,which is supplemented by a switchable driver amplifier to increase the isolation between channels in the CommonLeg structure and eliminate oscillation loops in the transceiver link.The final multifunction chip can realize the functions of transceiver channel switching and 6-bit highprecision amplitude and phase control.