Research And Design Of Novel LTCC Power Divider

With the rapid development of the modern mobile communication and the high-integration system,the RF devices are developing towards the direction of miniaturization,low cost and high performance.The design of laminated three-dimensional layout based on LTCC(Low Temperature Co-fired Ceramic,LTCC)can effectively reduce the volume of RF devices,so as to realize new requires of miniaturization,low cost and high performance in new wireless communication system.The ring hybrid with lumped elements in this thesis is proposed by using the equivalent network instead of the microstrip lines of one quarter wavelength and three quarter wavelength.Then power divider with arbitrary center frequency and arbitrary output power ratio by changing impedance.Secondly,the equivalent network theory is used to obtain the parameters of the equivalent model.The design of ring hybrid in this thesis include equal power output ratio and unequal power output ratio 1:2? 1:4,and the design of the operating frequency are respectively 100 MHz?600MHz and 950 MHz.In this thesis the branch-line include two models,one of which is 450 MHz,and the output power ratio are respectively 1:1 and 1:2.The other is 922 MHz,and the output power ratio is 1:9.Finally,the physical size of the ring hybrid and the branch-line are 5.3mm*6.3mm*0.88 mm.In order to obtain the wide bandwidth of ring hybrid,this thesis is proposed an original approach by cascade circuit so that the double ? and double T model can instead of the microstrip lines of one quarter wavelength and three quarter wavelength.In order to verify the broadband ring hybrid,this thesis is proposed an improved circuit at 100 MHz.We design equal power output ratio and unequal power output ratio 1:2 of two ring hybrids,and results are consistent with the designed index within error range.Finally the electromagnetic simulation results of the designed branch-line and ring hybrid are compared with test results,we can obtain the measured results and simulation results are consistent within a certain extent and therefore verify the correctness of the designed theory.