| Millimeter wave has always been a popular research direction in both military and civil fields,such as radar,satellite communication,security detection and additional prevalent use cases for millimeter wave technology.The rapid progress of 5G millimeter wave communication in recent years has propelled the research on millimeter wave to unprecedented levels.As the key part of millimeter wave system,it is of great significance to study the frequency conversion component.The topic of this paper comes from the W-band multi-channel frequency conversion module project proposed by CASIC,it can be used for W band system test.Firstly,the research background and significance of frequency conversion module are described,the domestic and foreign research status and related development trend are introduced,and the overall design direction of frequency conversion module is clarified according to the relevant technical scheme and principle.Combined with the modular design idea,this component adopts the scheme of "multiple frequency conversion + switch selection",which not only effectively reduces the risk of mirror frequency interference,but also simplifies the link design of multi-IF(Intermediate Frequency)channel.Then select the key components for each link and design the passive circuit simulation.Finally,a W-band frequency conversion module with multi-channel,large dynamic range and good flatness is completed.The upconversion module realizes the upconversion of70 MHz/4.5 GHz multi-channel IF signal to 92-96 GHz RF(Radio Frequency)signal,the output RF power is greater than 3 d Bm,the dynamic range is greater than 120 d B,and the in-band flatness less than ±2 d B.The downconversion module realizes the downconversion of 92-96 GHz RF signals to 70 MHz/4.5 GHz IF signals,with channel gain basically reaching 40 d B,dynamic range greater than 100 d B,and flatness less than ±2 d B.In the initial scheme of frequency conversion components,it is necessary to design a W band high and intermediate frequency mixer.This paper uses DMK2308 reverse parallel diode,and combines the method of field circuit co-simulation to design the W band high IF mixer.A T-type duplex structure is proposed in the design,which achieves good high and intermediate frequency performance.It is known through simulation that when the operating frequency range of the RF signal is between 89 and 99 GHz,and the LO(Local Oscillator)signal frequency is40 GHz,the conversion loss for generating an IF signal between 9 and 19 GHz is less than 10 d B,measured conversion loss is 10～14.5d B.Then on the basis of this mixer,the transmission line is changed to the mode of suspended microstrip line,and the duplex structure is modified to achieve further optimization of the mixer.As the task cycle for the W-band frequency conversion module is four months,the progress of the design work for the W-band high intermediate frequency mixer could not meet the task cycle requirement.As a result,a chip solution was used instead.However,due to the high cost of the chip solution,designing the mixer in-house still presents a cost-effective option and could be utilized in other projects in the future. |
PDF Full Text Request