Design Of Miniaturized Power Dividers Based On Planar Slow-Wave Structure

With the development of communication systems,RF front-end systems,the miniaturization design of passive microwave components of RF front-end systems such as power dividers has become particularly critical.Because the slow-wave structure can reduce the size of passive microwave components,so the transmission line of the slowwave structure can be used to reduce the size of the power divider.Moreover,the bandwidth and harmonic suppression performance of the power divider is crucial on the application of the power divider.Therefore,in this thesis,miniaturization of power dividers is investigated by using coplanar waveguide slow-wave structures,and the broadband power divider is proposed by using lattice structure on coplanar waveguide slow-wave transmission line.The power divider with harmonic suppression performance is miniaturized by loading resonators.The main contents of this thesis are as follows:1.A slow-wave transmission line based on coplanar waveguide transmission line with high and low impedance lines and defected ground structure is proposed.The line is applied to the miniaturized design of Wilkinson power divider.The designed Wilkinson power divider is operated at 1.8 GHz and the size is only 48% of the structure size with conventional coplanar waveguide transmission line.2.A lattice structure is realized on the coplanar waveguide structure by loading spiral coupling capacitors and high and low impedance lines.By combining with the traditional coplanar waveguide,a hybrid slow wave transmission line a hybrid structure of slow-wave transmission line based on lattice structure and conventional ?-type structure is designed,which is used expand the bandwidth of slow-wave transmission line.by applying the slowwave transmission line to the Wilkinson power divider design,the bandwidth of the Wilkinson power divider is significantly expanded while the Wilkinson power divider is miniaturized.The operating frequency of the power divider is 1.8 GHz,and the 10 d B fractional bandwidth is 202.0%,and its size is only 41.5% of the conventional coplanar transmission line design.3.A slow wave transmission line with low pass filtering effect is designed by loading rectangular resonators,T resonators and meandered lines on microstrip lines.The transmission line has a wide stopband because the resonator can provide additional zeropoint of transmission to the transmission line,thus the resonator extend the stopband width of the transmission line.A miniaturized Wilkinson power divider with filtering performance and wide stopband performance is designed.The frequency point of the power divider is 0.9 GHz.the size is only 37.4% of the size of the Wilkinson power divider based on the conventional structure,and the power divider has good stopband rejection in the frequency range of 1.75 GHz-14.00 GHz.