Research On Reconfigurable Key Components In Microwave Systems

With the increasing functions of wireless communication and radar systems,radio spectrum is becoming more and more crowded and system's ability to adapt to more complex environment and so on development trend,the requirements to microwave system are more and more darder.5G smartphones requirements such as the future downward compatible with previous generations of wireless communication standards,and at the same time support Bluetooth,WLAN and GPS and other communication mode,and such as radar for future communication,vigilance,navigation,detection and guidance,and other functions.These requirements make microwave devices and antennas in the microwave system more and more numerous,the system more and more complex,and the volume and cost are higher and higher.The interference between these large amounts of microwave devices and antennas also reduces the performance of the microwave system and can't even work.In order to solve the above problems,reconfigurable technology emerges.Reconfigurable technology is designed to use a single component to implement the system's many functions.However,as the basic period carrier of reconfigurable technology,microwave reconfigurable components still have problems such as large insertion loss,small dynamic range and unstable performance.Frequency reconfigurable filtering power divider,tunable phase shifter and linearly polarized reconfigurable antenna are mainly researched.Follows are the main contributions.For the problem that the quantity of tunable components increases with additional ports and modes,a tunable component sharing technology is presented for the design of reconfigurable filtering power divider(RFPD).With this technology,three 2-way power dividers are designed.The first one is a single frequency band RFPD with just a single varactor.The second one is a dual-mode RFPD with extra out-of-band rejection property.The last one is a dual-band tunable with two independent tunable frequency bnads.This tunable component sharing technology can not only reduce the size and cost of the system but also improve its insertion loss and consumption.For the problem that the insertion loss of phase shifter increases with the increasing of phase shift and the balancing of insertion loss fluctuation,a design for the reconfigurable reflective phase shifter considering the maximum relative phase shift,insertion loss and its fluctuation are presented.With this method,a miniaturized reconfigurable reflective phase shifter with 40% reduction of the size and a reconfigurable reflective phase shifter with fewer lumped components are proposed which reduce the scale and the design complexity of phase shifter,respectively.The system ultilzing these phase shifters is benefitting of low cost,small size and high performance.For the problem that phase shifters are required to be not only matched in wide-band but maintaining the phase shift in given band,a design based on restrictions for the wide-band reconfigurable reflective phase shifter considering the maximum relative phase shift,insertion loss and its fluctuation is presented to reduce the phase shift fluctuation and improve the performance of phase shifter.This phase shifter can be used in wide band microwave system.For the problem that it's difficult to analyze the complicated feeding network due to its idealness,the error of linear polarization and the increase of cross-polarization,a matrix analysis method based on the interconnection of S-parameter matrix of arbitrary ports is presented to analyze the performance of linear polarization reconfigurable antenna.A linearly polarized reconfigurable antenna based on left and right hand composite transmission line is proposed.With the contol of the votage,the linear polarization can be controlled from 0 to 180°.What's more,a linearly polarized reconfigurable antenna based on SIW are proposed as well.The linear polarization can be also controlled from 0 to 180° by rotating the coxial to SIW transimison.These linear polarization antennas can be used in microwave system demanding the continuously of the polarization of the antennas.