Research On Compact Multi-way Millimeter-wave Power Combining Amplifier

In recent years,with the rapid development of radio communication technology,millimeter wave technology has been widely studied as a cutting-edge communication technology to overcome the bottleneck of the past technology.However,the output power of a single solid-state device decreases as the frequency increases,and it is difficult to meet the application requirements in the millimeter wave band.Therefore,in order to obtain high-power millimeter-wave signals,radial power combiner/divider aiming at synthesizing various power signals have become research hotspots.In addition,how to ensure the stability of the active solid-state power amplifier and passive power combiner/distributor after assembly is also the key to research.This thesis mainly focusses on the high-isolation radial waveguide power divider/combiner.In addition,two types of millimeter wave power combining amplifiers are designed based on the coplanar arm waveguide magic T.The major tasks are as follows:1.A Ku-band 8-way radial-waveguide power divider/combiner with improved isolation was designed.In this structure,a through slot is designed on a radial waveguide disk between each adjacent port,and a resistive film is covered on the other surface,so that the resistive slots improves the isolation characteristics between ports.This thesis gives the design steps and simulation process.Finally,the power divider/combiner is processed and measured,and measured results have been analyzed.The measured results show that the method has a certain effect on improving the isolation characteristics.2.A rectangular waveguide TE₁₀ mode to circular waveguide TM₀₁ mode converter based on H-T power divider network with wide bandwidth was designed.After the signal enters from the rectangular waveguide,a four-way H-T power divider network is used to obtain four equal-amplitude signals with the same phase and then fed into the circular waveguide.According to the magnetic field characteristics of the rectangular waveguide TE₁₀ mode and the circular waveguide TM₀₁ mode,circular waveguide TM₀₁ mode is finally excited.This thesis elaborates its working principle,and gives detailed design steps and simulation process.Finally,a Ka-band mode converter has been fabricated and measured.The measured results meet the design requirements,and it has high mode rejection and conversion efficiency.3.A high isolation 36-way waveguide power divider/combiner based on the mode converter introduced above was designed.With the mode converter,a full-metal radial waveguide power divider/combiner can be realized,and the power capacity increases.In addition,the above structure also adopts the above method of improving the port isolation characteristics of the radial waveguide power divider/combiner.Opening the slot on the waveguide disk and covering it with a resistive film on the other side to improve the port isolation.In this thesis,the principle of the radial waveguide power divider/combiner is introduced,and the design steps and the simulation process are explained in detail.Finally,the measured results are performed.The results show that the structure has good bandwidth characteristics and isolation characteristics,and the role of the resistive isolation slots is verified.4.A four-way power combining amplifier and an eight-way power combining amplifier based on coplanar-arms waveguide magic T were designed.The combining network of the four-way power combining amplifier belongs to the back-to-back structure of the coplanar-arms waveguide magic-T.The power combining network of the eight-way power combing amplifier is based on the traveling wave structure and coplanar-arms waveguide magic-T.After designing,simulating,fabricating and measuring a passive power combining network,two power combiner amplifiers are assembled.The two power combiner amplifiers are only60mm*40mm*25mm in size,and their combining efficiency is greater than 80%in the 29-32GHz frequency range.