Research Of A New W-band Radial Power Combining Technology

Millimeter wave technology has been widely used in radar,guidance,communications,imaging,measurement and other fields after years of development.The power amplifier is an important part of the millimeter-wave system,but the power output capability of a single device decreases rapidly as the operating frequency increases.In order to meet system requirements,the power output capability needs to be doubled.On the other hand,the increase in operating frequency means better accuracy,greater data bandwidth,and faster transmission rates for millimeter-wave systems.Therefore,the development of power combining technology for high-end millimeter-wave and even terahertz frequency bands is currently a research hotspot,which is of great significance for the development of new system applications and achieving better system performance.This topic is based on waveguide space power combine technology and proposes a new W-band radial power combine technology,as follows:In order to overcome the shortcomings of the TE₀₁ order of the circular waveguide in traditional radial power combiner technology,the TE₀₁ mode of the sector waveguide is selected as the reduced mode of the TE₀₁ mode of the circular waveguide.By selecting an appropriate fan angle,the order of the TE₀₁ mode in the sector waveguide can be reduced,and the number of suppression modes required to transmit the TE₀₁1 mode can be reduced.According to the different fan angles,different mode converter models are proposed.A 7-path power combiner is designed using a sector waveguide with a fan angle of 180 degrees.The combiner has asymmetric structure and the transmission mode is symmetrical along the circumference.Features.The simulation results show that the return loss of the combiner is better than 19d B in the band of 87⁹8GHz,the insertion loss of the combiner is less than 0.25dB,and the synthesis efficiency is greater than 94%.Finally,the 180-degree sector waveguide radial power combiner was processed.The test results show that the synthesis efficiency of the combiner is 85%.A combination of circular waveguide mode(circularly polarized TE₁₁ mode)is proposed for radial power combiner.This method is proposed so that the mode without radial spatial symmetry can be used in the field of radial power combiner.The device provides more alternative modes of operation.Using the vector network analysis method,the conditions for stimulating circularly polarized TE₁₁ modes are determined,and a balanced mode converter for the TE₁₀ mode from a rectangular waveguide to a TE₁₁ mode in a circular waveguide is newly designed.Then,a TE₁₁ mode based on a circular waveguide is proposed and designed.In the power combiner,7-channel and 14-channel power combiners were designed in the band of 87-98 GHz.The simulation results show that the return loss of the 14-path power combiner is better than 27 dB,and the insertion loss is less than 0.4 dB.The efficiency is greater than 91%;the return loss of the path-to-power combiner is better than 30dB,the insertion loss is less than 0.2d B,and the synthesis efficiency is greater than 95%.Finally,the 14-way power combiner was processed and tested.The measurement results show that the return loss of the 14-way circular waveguide TE₁₁ mode radial power combiner is greater than 16dB,and the synthesis efficiency is greater than 84%.At the optimum position,the synthesis efficiency can reach more than 87.6%.