The Research Of Tan Microwave Power Film Load And Isolator In Ferrite Substrate

All microwave systems consist of many different functional microwave components and microwave devices. The miniaturization and integration of microwave device is a hot issue in the application field of development. As a class of common components microwave devices and microwave systems, microwave power load is extensively applied in communications, radar, detection and other areas. Based on this context, paper studied the properties of TaN thin film materials on Ni-Zn ferrite and prepared microwave power thin films load, and on this basis, prepared microwave integrated isolator, and then got some conclusions.Experiment prepared thin films prepared TaN on Ni-Zn ferrite, by using reactive dc magnetron sputtering method, and studied the effects of nitrogen flow rate on the electrical properties of thin films. As the nitrogen flow increases from 2sccm to 7sccm, TaN film deposition rate decreases from 18nm/min to 10.5nm/min, and TaN square resistance increases from 25?/sq to 235?/sq, and absolute value of its TCR which is negative, increases from 50 ppm / ℃increased to 380 ppm / ℃. By studying the influence of Cu doping to TaN film properties, experiment found that film deposition rate with Cu doping is larger than those without Cu doping, film square resistance with Cu doping is larger than those without Cu doping, film TCR absolute value with Cu doping is smaller than those without Cu doping. Cu doping can effectively adjust the film square resistance and the TCR, and Cu which has a positive TCR could effectively make up the big negative TCR of TaN thin films. Experiment determined the optimum preparation parameters of the thin film resistor is argon flow 50 sccm, nitrogen flow 3sccm, sputtering power 40 W, sputtering time 20 min, and the film obtained by the parameters is useful to prepare film load which impedance matching of is 50?, and the film TCR values is smaller which the value of is-50 ppm/℃.By using HFSS software, experiment designed and simulated the microwave power TaN film load base on ferrite, which the simulation and optimization VSWR result of is 1.2 or less in the DC-20 GHz band, and after that, experiment prepared microwave load on ferrite. The frequency performance and the power performance were tested. The VSWR of prepared load is less than 1.5 in DC-20 GHz frequency range, which shows it has good frequency property, and its rated absorbed power is 1W.The load was applied to the circulator, and they together make up the isolator. Experiment studied the integration of device simply. Microwave integrated isolator is made up by junction circulator and load inside a port of junction circulator. With HFSS software, experiment designed excellent performance circulator within 8GHz-12 GHz frequency band, and then constructed microwave integrated isolator. Through simulating microwave performance of isolator in the 8GHz-12 GHz band, experiment got its port return loss is greater than-12 dB, and S21 insertion loss is less than-2dB, and isolation S12 is greater than-13 dB. After preparing isolator by photolithography process and some other processes, experiment tested microwave performance of isolator. The results show that in the 8GHz-12 GHz band its port return loss is greater than-10 dB, and insertion loss is less than-5dB, and isolation S12 is larger than-7dB. It already has function of transmission signal and reverse isolation, which verify the possibility of device miniaturization and integration.