Research On Dispersion Characteristics And Devices Of Magnetostatic Wave

The research of the Thesis has put emphasis on the design of the magnetostatic backward volume wave notch filter and the magnetostatic wave non-dispersive delay line.Firstly,the dispersive equations of the magnetostatic surface wave and the backward volume wave were obtained by the magnetostatic approximation.The radiation resistance equations of these two magnetostatic waves were obtained according to the fundamental theory of radiation resistance.Then the method of implicit function derivation was used to obtain the equation of group delay.The effects of changing parameters in the magnetostatic surface wave and backward volume wave equations were discussed by mathematical software,thus accumulating theoretical basis for designing magnetostatic wave devices.Based on this theoretical basis,the magnetostatic wave band-stop filter and delay line were researched respectively in the thesis.A magnetostatic backward volume wave notch filter that can be tuned in the4?6GHz frequency band has been designed in this thesis.The theoretical calculation of the magnetostatic backward volume wave radiation resistance and stopband depth,the design of the coplanar waveguide and simulation of the device were included in its design process.The device has been tested after each part of the device was assembled.The designed magnetostatic backward volume wave notch filter had good performance,its passband insert loss was less than 3d B,its half depth bandwidth was100MHz±5MHz and the stopband depth was-10?-13 d B.Since the magnetostatic surface wave and the magnetostatic backward volume wave have dispersive delay characteristics with opposite slopes in their excitation frequency domains.The principle of magnetostatic wave non-dispersive delay line is to cascade these two magnetostatic waves in their common excitation frequency domain.In the thesis,a method that obtaining the common excitation frequency domain of these two magnetostatic waves was proposed by using YIG single crystal films with different saturation magnetizations and applying the same strength external bias magnetic field.After that,the simulation and design of the microstrip line,the curve fitting of the non-dispersive group delay and research on integration of magnetostatic wave dispersive delay lines and non-dispersive delay lines in the same device have been implemented,thus making magnetostatic wave devices further integrated and multi-functional.Finally,after tested,the designed magnetostatic surface wave dispersive delay line can be tuned in the 4?6GHz frequency band.It had the bandwidth of 300 MHz when the insertion loss was twice than peak value,the number of group delay was 17?61ns within this bandwidth,the out-of-band rejection was-45?-50 d B,the maximum passband insert loss was-6?-7d B.In addition,the non-reciprocity of the magnetostatic surface wave was also tested.The amplitude peak value of the magnetostatic surface wave caused by a YIG single crystal film which thickness was28?m had the 12 d B insert loss difference and 24° phase shift.The designed magnetostatic backward volume wave dispersive delay line can be tuned in the 4?6GHz frequency band,It had a bandwidth of 260 MHz when the insertion loss was twice than peak value,the number of group delay was 20?54ns within this bandwidth,the out-of-band rejection was-45?-50 d B,the maximum passband insertion loss was-19?-22 d B.The non-dispersive delay line cascaded by these two magnetostatic waves had the passband bandwidth of 30 MHz and the number of group delay was 22ns.