Millimeter-Wave Temperature-compensated Linearizer

In recent decades,the demand for communication in human society has been increasing,and the requirements for communication quality have also become higher and higher,which has made tremendous development and progress in communication technology.Especially in the current situation where spectrum resources are becoming scarce,the communication technology of the millimeter wave band has received extensive attention.Based on the characteristics of millimeter wave high speed,high capacity and miniaturization,it has been highly used and developed in military and civilian fields.In the context of increasingly crowded spectrum resources,modulation methods with relatively high complexity have to be adopted to improve the utilization efficiency of spectrum resources.In addition,in order to reduce power consumption,the efficiency of the amplifier in the transmitter needs to be improved.High efficiency will inevitably make the linearity of the amplifier decrease.Therefore,analog predistortion technology has been widely studied and applied as an important method to improve linearity.However,since the Schottky diode is used in the analog predistortion linearizer,the characteristics of the Schottky diode will be significantly affected when the temperature of the external environment changes.Therefore,temperature compensation of the linearizer is also very important.In this thesis,two linearizers with different structures will be developed in the millimeter wave band,and the corresponding temperature compensation research and test will be performed on them.The main research contents are as follows:The first is to design a transmission predistortion linearizer for the central operating frequency of 30 GHz,and use a simple and effective temperature compensation method for it.The test results indicate that the predistortion linearizer can provide 5dB gain expansion and 12° phase expansion at the center operating frequency of 30 GHz.After temperature compensation of the predistortion linearizer,the measured results showed that the gain fluctuation range was reduced from 4dB to 2.2dB in the temperature range of-5? to 50?,and the phase fluctuation range was reduced from 5° to 2°.Subsequently,a reflective predistortion linearizer with an operating bandwidth of 28 GHz to 32 GHz was designed based on Schottky diodes and temperature-compensated.On the basis of the previous temperature compensation method,an NTC thermistor is further introduced to enhance the effect of temperature compensation.The simulation results show that the gain and phase of the predistortion linearizer with temperature fluctuation range have been further reduced small.The actual test results show that the reflective predistortion linearizer can provide 6dB gain expansion and 50° phase expansion at the center frequency of 30 GHz.After temperature compensation,the reflective predistortion linearizer's gain-temperature fluctuation range from 3dB to 1.8dB in the temperature range of-5°C to 50°C,and the phase fluctuation range from 10° to 5°.