Research On Waveguide Packaging Technology And Integrated Lens Antenna For UTC-PD

Terahertz wave has wide application prospects in many fields such as wireless communication,material detection,radar imaging,and has been favored by scholars from various disciplines due to its unique nature.Among them,efficient terahertz radiation sources are the key to the development and application of terahertz technology.Terahertz sources based on unitraveling-carrier photodiode(UTC-PD)are key devices for high-speed wireless communication links with the advantages of roomtemperature operation,continuous output,and wideband tunability.For the two different output modes of rectangular waveguide and antenna radiation,this paper studies the waveguide packaging technology and integrated lens antenna technology of UTC-PD.The main research contents are as follows:1.An improved UTC-PD waveguide packaging structure is proposed to solve the problem of RF energy leakage from the DC path,which integrates the microstrip-to-rectangular waveguide transition with a bias tee.The microstrip-to-rectangular-waveguide transition is in the form of an E-plane probe,and impedance matching is achieved by using a high resistance line connected in series.The bias tee uses a 1/4 wavelength high resistance line and a 1/4 wavelength sector stub to realize RF open circuit and avoid energy leakage.The combination of the two forms the overall circuit of the package structure and the processing and measurement of the back-to-back structure are completed.The measurement results show that the back-to-back structure has an average insertion loss of 0.7 dB and a return loss of more than 10 dB in the frequency range of 75-110 GHz,which verifies the feasibility of the packaging structure.An improved packaging scheme for waveguide output UTC-PD module is given.2.A novel UTC-PD integrated equiangular spiral antenna with a dielectric lens is proposed.Firstly,the radiation mechanism of the equiangular spiral antenna is analyzed,and its frequency-independent characteristic is described.The size of the equiangular spiral antenna is designed according to the effective radiation area,and the antenna is monolithically integrated with the UTC-PD.The on-chip antenna is placed on the silicon dielectric lens.The silicon lens can eliminate the surface waves generated by the discontinuity of the optical properties between the substrate and free space,and focus the beam to enhance the directivity of the antenna.The simulation results show that the UTC-PD integrated lens antenna has a return loss of more than 10 dB in 0.1-1.8 THz band,an axial ratio of less than 3 dB in 0.1-0.7 THz band,a gain of 30.6 dBi and a beam width of 3.9° at 1.1 THz.