Research On Microwave And Millimeter Wave Broadband Power Combining Technology

Microwave and millimeter-wave broadband solid-state power sources are the core components in radar,communications and other application systems.High-power broadband solid-state sources are an important topic in this research field.Broadband power combining technology is an effective means to increase the output power of solid-state sources.At the same time,with the development and popularization of large-scale broadband phased array antenna technology,the technical demand for multi-channel high-integration power dividing/combining feed network is also increasing.Under such application background,this paper has made in-depth research on the multi-layer planar ultra-wideband multi-channel power dividing/combining feed network technology and the millimeter wave power combining amplifier based on the waveguide type power dividing/combining network.The main research contents are as follows:1?Based on the theory of multi-port network,the factors affecting the combining efficiency of power combining amplifier were theoretically modeled and analyzed with S parameter.The analytical relationship between the combining efficiency and the amplitude and phase of each power amplifier unit branch and the loss of the combining network circuit is derived.Based on this,the effects of amplitude and phase consistency,circuit loss on the best combining efficiency are analyzed,and the design criteria of broadband power dividing/combining passive network are discussed.2?Aiming at the technical difficulties in designing the multi-level Wilkinson power divider circuit of the stripline structure of the ultra-wideband multilayer planar circuit,using full-wave simulation software,optimized design of thin-film isolation resistors,improved single-stage broadband Wilkinson power splitter design,multi-level broadband Wilkinson power split circuit overall simulation optimization,and solved key technical issues such as broadband vertical blind hole interconnection optimization design.5-10GHz and 5-16GHz planar buried resistance multilayer boards eight-channel ultra-wideband Wilkinson power dividing/combining networks are designed.The experimental samples were processed and tested for parameters such as port standing wave ratio,power division amplitude and phase balance,and insertion loss.The test results show that for the 5-10GHz power dividing network,the return loss of the input and output ports is better than 12dB and 14dB,the transmission loss consistency between the channels is better than±0.45dB,and the phase difference is better than±2°.In any continuous 2GHz frequency band,the power transmission flatness is better than±0.5dB,and the adjacent port isolation is better than20dB,and the non-adjacent port isolation is better than 25dB.For the 5-16GHz power dividing network,the input and output return loss is better than 9.0dB and 12.0dB,the transmission loss consistency between channels is better than±0.5dB,and the phase difference is better than±5°.In any continuous 2GHz frequency band,the power flatness is better than±0.65dB,and the isolation between adjacent output ports is better than 14dB,and the isolation between non-adjacent ports is better than 20.0dB.3?In order to realize a waveguide type power dividing/combining network with low loss and excellent standing wave characteristics in V-band,Using the combination of waveguide Y-type power splitter and branched 3dB directional coupler,the use of Y-type power splitter with small loss and 3dB directional coupler is beneficial to improve the characteristics of standing waves,and simulation analysis and design of a V-band four-way waveguide power dividing/combining network.Using the transition structure of waveguide-microstrip probe-microstrip,the characteristics of the four-pass passive power dividing/combining network were tested in a back-to-back way with power dividing and combining network.The typical insertion loss of the back-to-back structure is 2.4dB,and the typical loss of the single-sided power dividing/combining network and microstrip probe is 1.2dB,which achieves excellent insertion loss performance.On this basis,a V-band four-way power combining amplifier was developed using a V-band domestic power amplifier MMIC chip with an output power of 23dBm.Experimental test results show that in the 57-65GHz operating frequency band range,the V-band four-way power combining amplifier has a saturated output power of 28.0dBm and a peak power of 28.6dBm.4?In order to improve the isolation between the output ports of the traditional waveguide Y-type power splitter,a ceramic substrate with a resistive film inserted in the center of the H surface of the Y-junction common waveguide is used to form an isolation resistor on the common decomposition surface.An E-band high isolation Y-shaped waveguide power splitter was developed.The resistance film is formed by symmetrically coating Ta N resistance material on both sides of the Al₂O₃ ceramic substrate.The structure of this waveguide power splitter was modeled and analyzed by using HFSS.The effects of ceramic substrate installation depth and installation position deviation,resistance processing error on port standing wave,loss and isolation are investigated in detail.Combined with the parameter optimization results,an E-band high isolation Y-type power splitter experimental sample was produced.The test results show that in the 71-77GHz frequency band,the typical insertion loss of the two output branches is 3.5dB,and the transmission loss consistency is better than±0.1dB.Compared with the traditional waveguide Y-type power splitter,in the 71-74GHz frequency band,the isolation is better than 10dB and the improvement is above4dB.In the 74-80GHz frequency band,the isolation is better than 13dB and the improvement is above 7dB.