Study On Power Reconfigurable Network And Reconfigurable Impedance Matching Network

Traditional RF circuits are widely used in communication,radar and positioning systems.With the development of technology and the emergence of complex communication scenarios,higher requirements are put forward for flexibility of communication,radar and positioning systems.However,traditional RF circuits are designed for a single function.For example,the power ratio of the power divider,the load impedance value matched by the impedance transformer,the number of poles and zeros of the filter,and the coupling coefficient of the coupler cannot be changed after determined.The reconfigurable radio frequency circuit considers the reconfiguration characteristics on the basis of the traditional radio frequency circuit.On the basis of the traditional radio frequency circuit design,some electronic control components are added so that some parameters of the reconfigurable radio frequency circuit are changed by electronic control.According to the practical problems encountered in reconfigurable circuit design,two reconfigurable circuits,power reconstruction network and reconfigurable impedance matching network,are studied by a EM/Circuit co-simulation method based on full-wave de-embedding method.The power reconfigurable network is applied to power control in the case of multiple inputs.It can realize multiple inputs combining or one input dividing or multiple inputs working independently without affecting each other.Firstly,the topology of the reconfigurable power divider is extended to obtain the topology of the power reconfigurable network.Then the circuit implementation of the power reconfigurable network is given according to the topology.Finally,a 2 × 2 power reconfigurable network is designed and fabricated.The test results show that the insertion loss of the 2×2 power reconfigurable network is less than 1.92 dB and the return loss is greater than 22.8dB considering the three working states.Reconfigurable impedance matching network is used to match the input impedance to the port impedance as a matching circuit for a reconfigurable radio frequency circuit or a reconfigurable antenna in different operating modes.A new reconfigurable impedance matching network structure based on the model of PIN diode is proposed in this thesis.Two different input impedances can be matched using only one branch embedded in the PIN diode without other lumped component.In addition,a method for simplifing the solution of matching stub's lengths for this structure is also proposes.Each parameters of the reconfigurable impedance matching network can be expressed in the form of an analytical solution by this method and the error is within an acceptable range.The test results show that the reconfigurable impedance matching network has an insertion loss of less than 0.4dB and a return loss of more than 30 dB both in the state of matching two different input impedances,and the consistency between the simulation and the measured results is good.