The Development Of Integrated 3Mm Transceiver Front End With Dielectric Lens

In recent years,the application of W-band in civil and military fields has received more and more attention,especially the relatively wide available bandwidth and small antenna size in this band make it attractive for high-resolution imaging systems.In this thesis,a integrated 3mm transceiver front end system with dielectric lens is developed by using the hybrid integration method of waveguide and microstrip.Firstly,the overall frame of system is determined,then the overall index of the system is planned,and the index is decomposed to each specific component,and finally the development of each active and passive core component is completed.Firstly,the dielectric lens antenna is developed,the feed antenna adopted the form of microstrip patch,and used a combination of a circular feed patch and slot and a gradual feed slot gap width to achieve high electromagnetic coupling.While the slot loading method is used to widen the bandwidth of the antenna to form an ultra-wideband antenna model,and the radiation patch at the input end is changed to a stepped shape to improve impedance.Then according to the feed antenna,the type of lens is selected as a spherical lens,which is easy to focus and process and assemble,and can be embedded above the feed and combined into a lens antenna to achieve antenna beam convergence and gain enhancement.Compared with the conventional patch antenna,the gain can reach 21 dB and the bandwidth is also broadened.Moreover,compared with other dielectric lens antennas of the same type,the size is smaller(feed 15*15mm,lens radius R=7mm)and the side lobe suppression is relatively higher(18dB)under the condition of similar gain and beam width.The waveguide to microstrip transition structure adopted the waveguide-probe-microstrip transition structure to make the link easy to process and assemble,and the test results of the transition structure meet the actual needs.The filter adopted the Hmembrane waveguide filter structure,placed in a section of the waveguide cavity between the waveguide port and the microstrip transition,which makes full use of the link space and achieves lower insertion loss,higher out-of-band suppression and better in-band flatness.The active components of the transceiver link in this paper all selected monolithic microwave integrated circuit(MMIC)design.In the design of low noise amplifier,through a series of designs such as chip selection,stability analysis,bias circuit design and simulation design of chip cavity,the noise coefficient of amplifier is less than 3.3dB and the gain is 21±1.5dB.The design of the power amplifier uses a chip of GaN material.The test shows that the output power is greater than 18 dBm.The transceiver switch chip adopts gotmic company's single pole and double throw switch to realize the isolation of the transceiver link.Based on the development of each key component to meet the requirements of the subject,the link structure of the whole system is laid out,and a cavity that can realize integration is designed,and some core technical indicators are teste.The working bandwidth is 90~96GHz,and the noise factor of the receiving link is less than 3.5dB,the transmission link power is greater than 15 dBm,the subject design provides a reference for the future integration of millimeter wave multi-chip circuits and antennas.