A Research Of Multi-function Switched-beam Antenna Array

Because terahertz waves have the characteristics of non-ionizing and high penetrability,domestic and foreign research institutes have initiated an upsurge of research on the advanced technologies of terahertz in disciplines such as physical optics and electronics.It also has a broad research space in communications radar,which makes the terahertz transceiver system also has the value of discussion220GHz is the atmospheric transmission window.For this frequency band,there are a lot of researches on radar and satellite.There is no doubt that the mixer is an indispensable part of the receiving system,and the impact on the system performance is crucial.The harmonic mixer can reduce the difficulty of implementing the local oscillator source in the mixer and contribute to the miniaturization of the entire transceiver system.In addition,the third harmonic mixer developed in this paper is used in the 220 GHz radar transceiver system in this laboratory,which simplifies the components of the system.There’s important meaningIn this paper,the development of terahertz mixers and some research progresses of odd-order mixers are introduced.Then the principle of odd-order harmonic mixing is analyzed.Diode modeling is then determined based on the required indicators and processing feasibility.For each passive simulation part,in addition to the traditional high and low impedance filters,a CMRC filter is used in this paper to make the stopband of the filter wider and smaller.In the RF transition portion,the Schottky diode is flipped into the waveguide and the high frequency signal is applied to the die via a fin-waveguide transition.In order to confirm whether the signal can be successfully introduced into the diode,the HFSS and ADS software are used in this paper in combination,and based on this,the conversion loss of the entire circuit is determined by the same method.The result of the simulation circuit is: In the 190-230 GHz band,the conversion loss is 20±5dB,and the optimal frequency is 15 dB.The above circuit modeling and simulation results show that the mixer studied in this paper not only has better conversion loss but also has a wider operating bandwidth.After the processing is completed,the two test methods of fixed IF frequency and fixed LO frequency are adopted.The results show that when the conversion loss is less than 35 dB in the frequency band of 198-228 GHz,the conversion frequency at the best frequency is 24dB;fixed local oscillator test,the best frequency conversion loss is 24.6dB.At present,odd-order harmonic mixers in the terahertz-wave frequency band are not widely used in the world.The 220 GHz third-order mixer studied in this paper provides some experience for high-frequency odd-mix mixers,but there is still some optimization space.The optimization can be continued from two aspects of modeling and processing,reducing conversion loss.