| With the rapid development of integrated circuit technology,communication circuits have been developed to higher and higher frequency domains.In the field of wireless communications,data transmission places higher demands on wireless channel capacity and transmission rate.The millimeter wave has the advantages of wide bandwidth and good directivity,which can meet the needs of high-speed data transmission.The millimeter wave receiving circuit is an important part of the wireless communication system,and its performance plays a vital role in the whole system.This thesis uses the InP HEMT process,mainly researched around D-band receiver circuits and their broadband applications.Firstly,the InP HEMT device is used to analyze its structure and characteristics.On this basis,several passive components commonly used in circuit design are introduced and the advantages and disadvantages of three common receivers are compared.In this thesis,the design of the receiver circuit is based on a low noise amplifier and a mixer.According to the circuit design scheme,two D-band low noise amplifier circuits are designed based on the InP HEMT process.The low-noise amplifier uses a common-source amplifying circuit as the basic circuit structure.The first-stage circuit adopts minimum noise matching,and the latter stages of circuits consider the conjugate matching method for circuit design from the viewpoint of gain.In view of the circuit stability problem,two methods to improve the stability are adopted in the thesis.First,adding a resistor in the DC bias circuit and a bypass capacitor in the circuit to form a low-pass filter circuit,absorbing the low-frequency gain and preventing The circuit generates self-excitation at low frequencies,causing circuit instability.Another method is to add a RC series network between the gate and the drain of the tube,and use feedback circuits to improve circuit stability.The four-stage low noise amplifier circuit has a chip size of 1*0.62 mm2,and achieves a gain of more than 15 dB and a noise figure of less than 4.5 dB in the 110 GHz to 160 GHz band.In order to improve the circuit gain,a five-stage low noise amplifier circuit is designed based on this,and the circuit size is 1.2*0.62mm2.The feedback network of the five-stage circuit is different from the capacitance feedback network of the four-stage circuit,and the RC series feedback network is used.The simulation results show that the five-stage circuit achieves a gain greater than 20 dB in the 120 GHz to 150 GHz band.Compared to the four-stage low noise amplifier,the five-stage low noise amplifier circuit achieves higher gain in the wideband.For the down-conversion circuit,a D-band single-ended resistive mixer circuit is designed by using 0.5μm InP HEMT.In order to achieve large bandwidth and low conversion loss,both the local oscillator and the RF port use an open microstrip line for the matching circuit design.The IF low-pass filter circuit is composed of a series microstrip line and a parallel grounding capacitor.The chip size is 0.4*0.5mm2.The simulation results show that the conversion gain is-13.5～-9.7dB in the entire D-band.Compared with the same type of circuit structure in the same frequency band,this design has certain advantages in bandwidth and conversion loss.Finally,based on the design of the low noise amplifier and mixer circuit,the two parts of the circuit are cascaded to complete a D-band receiver circuit design.The simulation results of the whole receiver circuit layout show that the conversion gain of the circuit is 7-10dB in the frequency range of 120GHz to 150GHz,the noise figure is less than 12dB,the circuit size is 1.4*0.62mm2,and the circuit index basically meets the expected requirements.This thesis designs a D-band low noise amplifier circuit,a mixer circuit and a receiver circuit based on the InP HEMT process,which has certain reference significance and application value for the design and development of millimeter wave communication circuits. |
