Research On Millimeter Wave Frequency Doubling And Mixing Technology

Compared with microwave,millimeter wave has many advantages,such as wider frequency band,shorter wavelength and larger information capacity.Nowadays,it has been widely used in military and civil fields.It has great practical significance to study millimeter wave related technology.For all millimeter-wave applications,a stable and reliable millimeter-wave source is the foundation of everything.It is a common way to obtain millimeter-wave source by solid-state frequency doubling,which has a wide range of applications in millimeter-wave and terahertz bands.Similarly,the frequency conversion system solves the problem of millimeter-wave frequency conversion and plays an important role in millimeter-wave applications.Mixer is the core of the frequency conversion system.Its performance will have a great impact on the frequency conversion system,even the whole front-end of the receiver and transmitter.The research on frequency doubling and mixing technology related to millimeter wave application is one of the key directions of millimeter wave technology research.Based on the theory of diode frequency doubling and mixing,this paper designs a millimeter wave band six times frequency doubling link and a sub-harmonic mixer for millimeter wave imaging system.The design of the two devices is accomplished by the on-site simulation software HFSS and the circuit simulation software ADS.The key problem of designing the six-fold frequency doubling link is to realize a 88-104 GHz tripler.The tripler uses the reverse parallel beam lead Schottky resistive diode as a nonlinear device to form a balanced structure,a three-dimensional electromagnetic model of diode pair is established.The use of alumina ceramic with high dielectric constant as the substrate material of the whole frequency doubling circuit makes the original small millimeter wave circuit smaller and improves the fabrication accuracy.The test results of the sixth frequency doubling link show that the typical output power is 3dBm in required frequency band.The sub-harmonic mixer still uses ceramic substrate,and the whole circuit is a single-balance structure of branch type.Despite the use of hybrid integration,the size of the whole mixing circuit is still very small,and it is convenient to be integrated in different systems like a chip.The test results show that when the IF frequency is 4 GHz,the typical frequency conversion loss of the sub-harmonic mixer is 9 dB.It is believed that this study has a positive significance for the development of related technologies.