Research And Design On Silicon-Based Integrated Millimeter-wave Amplifier Circuits

With the increasing demand for high data rate wireless communication,millimeterwave integrated circuits on silicon-based technology have become an important part of social and economic construction,and have received extensive attention from countries around the world.In recent years,the development of millimeter-wave technique has advanced by leaps and bounds,and new demands are constantly emerging,resulting in related research facing new challenges at the three levels namely device,circuit and system.In order to meet these challenges,the millimeter-wave passive devices(on-chip spiral inductor)are firstly studied in-depth in this dissertation,an accurate millimeterwave ultra-wideband equivalent circuit model is established,and an accurate model basis is provided;Secondly,the key circuit modules(power amplifier and variable gain amplifier)in the wireless transceiver system are deeply studied,a large number of circuit design theories and engineering experience are accumulated,which provides certain circuit support;Finally,based on this device and circuit research,the broadband 5G millimeter-wave phased array system-on-chip research is carried out.The research work of this dissertation is mainly divided into the following five parts:1.Accurate broadband modeling of spiral inductor on silicon substrate and research on the influence mechanism of grounded guard ring.Aiming at the problem that the independent PAD on-chip spiral inductor structure lacks an accurate millimeter-wave ultra-wideband equivalent circuit model,an improved broadband equivalent circuit model is proposed,which greatly improves the accuracy of the original model.The tape-out verification shows that the proposed improved model achieves a high accuracy of Sparameter root mean square error(RMSE)less than 0.025 in the ultra-wide frequency range of 5-67 GHz.On the basis of this inductor model,in order to further improve the performance of the spiral inductor on the silicon substrate,the influence mechanism of the ground guard ring structure on the inductor itself is further studied.Through a large number of theoretical analysis and actual tape-out verification,it is found that the substrate doping and electromagnetic coupling effect of the ground guard ring are important factors affecting the performance of the inductor.2.Research on silicon-based millimeter-wave power amplifier based on transformer current combining technique.In order to achieve high output power and maintain high efficiency,the existing power combining techniques are deeply studied,and the detailed theoretical analysis and simulation verification are carried out focusing on the two power combining techniques based on transformer current type and voltage type.Secondly,in order to achieve the 1 d B compression point power improvement of the amplifier output without increasing the extra power consumption,the Taylor series method is used to analyze the gain expansion and compression characteristics of the transistor in-depth mechanism.Based on the above research,a high-performance power amplifier working in the Ka-band was designed by using transformer current combining and transistor gain expansion techniques.Using a 0.13 μm Si Ge Bi CMOS process,the PA achieves a saturated output power of 22.9 d Bm,an output 1 d B compression point power of 22.5d Bm,and a peak power-added efficiency of 21%.In addition,it achieves a peak power gain of 24.9 d B and a 3 d B bandwidth from 32 GHz to 39 GHz.3.Research on silicon-based millimeter-wave variable gain amplifier with high precision,strong robustness and low additional phase shift.First,in order to achieve low additional phase shift during gain tuning and at the same time keeping phase compensation robust to PVT changes,an active cross-neutralization phase compensation technique is proposed.Second,in order to effectively improve the gain step accuracy without increasing the complexity of the control circuit,an asymmetric capacitor gain step enhancement technique is proposed;Furthermore,in order to achieve precise gain control to reduce gain error,a high-precision gain control technique is proposed.Based on aforementioned three techniques,a digitally controlled variable gain amplifier operating at 23-28 GHz is designed based on a 65 nm CMOS process.The experimental results show that it achieves a linear gain tuning range of 6.2 d B and a fine gain step of0.2 d B;The RMS phase error is less than 0.92°,reaching a minimum value of 0.63° at27.8 GHz;The RMS gain error is less than 0.13 d B,reaching a minimum of 0.03 d B at25 GHz.4.Research on silicon-based millimeter-wave variable gain amplifier with reconfigurable gain tuning range and gain step.In order to effectively improve the flexibility of the current phased array system,a reconfigurable technique based on asymmetric capacitors is proposed,and the technique is theoretically deduced and verified by simulation in detail.Secondly,in order to realize the broadband performance while taking the in-band ripple into account,the transformer-based broadband matching technique is deeply studied.Based on the above techniques,a wideband reconfigurable variable gain amplifier operating at 21.4-29 GHz is designed using TSMC 65 nm CMOS process.The test results show that it achieves a reconfigurable gain tuning range of12.2/9.2/6.1 d B and a reconfigurable gain step of 0.4/0.3/0.2 d B,respectively.In addition,in the maximum gain tuning mode,an RMS phase error of 1.7° is achieved at 23.4 GHz,and an RMS phase error of less than 1.9° in the 20-30 GHz frequency range in the finest gain-stepping mode.5.Based on the research foundation of the above devices and circuits,the design of the high-gain broadband transceiver system chip based on the local oscillator phaseshifting architecture is further carried out.In order to effectively enhance the gain,bandwidth,noise and other performance of the transceiver system,and to achieve ultralow amplitude and phase errors without any calibration,a variety of innovative techniques such as impedance optimization,high-order resonance matching,system-level co-design,phase compensation and precision phase control have been introduced.Verified by the actual tape-out of 65 nm CMOS process,the system chip has achieved broadband design in RF,LO and IF ports.At the same time,the chip also achieves a RMS gain error of less than 0.63 d B and a RMS phase error of less than 2.4° in a wide frequency band without any calibration.