A Study And Design Of Microstrip Power Divider Integrated With Bandpass Filters

With the rapid development of radio frequency communication technology, the application of microwave radio circuits is more widely, and the requirements for that are much more than before. As an essential part of circuit devices in wireless radio communications system, power divider has also been widely used and deeply researched. In order to effectively reduce the sizes and the losses of microwave radio and frequency circuits, power divider integrated bandpass response is getting more and more attention. Moreover, filtering power divider can improve frequency selection and achieve power distribution.This paper studies the design of single frequency and multi-frequencies filtering power divider. Firstly, the paper introduces the theory of PD. And then, based on the traditional Wilkinson power divider, three single-, dual- and tri-band filtering PDs are designed. And the single- and dual-band PDs were processed. The main contents are as follows:First of all, based on the simple three-port network, the paper introduces the parameters and characteristics of the network. Then a quarter wavelength matching network is analyzed. Finally the paper puts the focus on the traditional Wilkinson power divider, and employs the odd-even mode method to analyze it in detail.Secondly, the paper designs a single band filtering PD. To design it, the coupling resonance theory is utilized. And the 1/4 wavelength converter in traditional Wilkinson power divider is replaced with resonator bandpass response. To improve the isolation, a similar Wilkinson structure is loaded at the input port. In addition, source-load coupling is applied to improve the frequency selectivity. The single-band PDs integrated filtering responses is implemented and measured, the measurement and simulation results show good agreement.Finally, two dual-band and tri-band PDs integrated filtering response are studied. A dual-band filtering PD is designed with the method of connecting passband in parallel, and it based on the single-band filtering PD which has been designed. The measured results validate the feasibility of this approach. By adjusting the impendence ratio of the multimode resonator, the paper designs a filtering PD with a triple-band response using minimum spurious resonance frequency. The design is also simulated.