Research And Design Of W-band Frequency Conversion Component

In the research of millimeter wave technology,the design and development of high-performance frequency conversion component has always been one of researcher's focus.At present,most millimeter-wave frequency conversion component are developed in the form of hybrid integrated circuits,which have the advantages of flexible circuit structure,simple process flow,and suitable for small batch production.According to the requirements of the subject index and the millimeter wave frequency conversion theory,this paper has completed the research and design,processing,assembly and test analysis of W-band frequency conversion component.First,based on the modular circuit design concept,the entire frequency conversion component is divided into four parts:the transmitting module,the receiving module,the local frequency doubling module,and the passive wave-guide network.The active components of each part adopt a separate cavity design to realize the space structure.On the electromagnetic isolation,the passive wave-guide network acts as a mounting carrier for each active component and takes into account the system's heat dissipation.Combined with the related frequency conversion theory,and according to the requirements of the project indicators,the overall system architecture and preliminary technical solutions of the sub-components were proposed.Among them,the transmitting component adopts the direct up-conversion scheme,the receiving component adopts the super-heterodyne scheme,and the local oscillator circuit uses the frequency doubling method to complete the design.Then,the design of the passive wave-guide network and the active components was completed according to the above-mentioned preliminary technical solution.Among them,the simulation software HFSS is used to design and simulate the functional devices involved in the passive circuit,such as wave-guide filters,equal proportion power divider,directional coupler,and so on.The simulation results in the frequency range of f_RF+1GHz show that the insertion loss of each device is less than 0.3dB and the emission coefficient is less than-20dB.Based on the design of each functional device,the overall passive circuit after cascade is simulated.After the design of each functional device is completed,the overall passive circuit is simulated and optimized,which helps to improve the inter-stage matching between the circuits.On the other hand,the design of active circuits is based on system requirements.First,this design makes detailed selection of device models,such as mixers,various amplifiers,and RF switches,and then makes detailed allocation of system indicators based on the parameters of the selected device,finally,the circuit assembly and layout drawings are given for the purpose of guiding production.Finally,after the circuit assembly is completed,the key indicators of the frequency conversion component are tested.The typical output power of the LO frequency multiplier circuit in the range of 78?108GHz is about 4.5dBm,and the power flatness is better than±1GHz,the local oscillator signal frequency range selected by this system is 86.2?88.2GHz,and its output power is about 3.75dBm±0.25dB,which meets the needs of frequency conversion;The test results show that the saturated output power of the transmitting component is greater than 12dBm in the frequency range of f_RF±1 GHz,and the power flatness in the pass-band is better than±0.5dB,in addition,the leakage power of the local oscillator signal at the RF side is less than-29dBm,and its relative suppression is above 40dBm,the above indicators all meet the design requirements.The linear conversion gain of the receiving component is about 26.5dB±0.7dB,and its 1dB power compression point is-13dBm,which meets the requirements of the index.In the frequency range of f_RF±1GHz,the maximum noise figure actual measured is 7.86dB,which is relative to the theoretical design index.In the last part,the test results are analyzed,and the development process is summarized.At the end of the article,the future work prospects are proposed for some optimizable points in the frequency conversion component.