Research On The Millimeter-wave Detectors With High Sensitivity

In recent years,as electronic information technology continues to develop rapidly,millimeter wave technology has been widely applied in communication,electronic countermeasure,imaging,radar,guidance and other systems.The millimeter wave detectors play an important role on many millimeter-wave systems such as test instruments,power detection devices,and direct detection receivers.It is also an essential device to ensure the millimeter-wave system work normally.The research of well-performed millimeter-wave detectors is of great significance to the application and development of millimeter wave technology.Therefore,this thesis focuses on the Ka band,W band and D band detectors.The three millimeter-wave detectors in this thesis are all designed based on Schottky barrier diodes.The main research contents include: passive transition structure,DC circuit,matching network,physical model of diode,low-pass filter and the whole detector circuit.According to the theoretical analysis and the requirements of project,the general schemes and indicators are determined.In order to keep the simulation results consistent with the test results,the impedance characteristics of diode are accurately analyzed by combining the field simulation and the circuit simulation.In addition,well-performed probe transition structure of waveguide-to-microstrip and waveguide-to-suspended stripline are designed.The stopband of compact low-pass filter is wide.According to the indicators,more reasonable matching networks and more complete entire structures are designed for the three different detectors.Finally,the Ka band broadband microstrip detector,the W band narrowband microstrip detector and the D band suspended stripline detector are successfully finished.The test results show that: the reflection coefficient of Ka band detector is lower than-4dB in most frequency range,which is a relatively flat.The sensitivity of the detection voltage in 34GHz-40 GHz is higher than 8000mV/mW,the peak point reaches 11757mV/mW,and the value of tangent sensitivity is about-59 dBm while the video bandwidth is 1.2kHz,which show good working performance.Compared with the simulation results of W band detector,frequency deviation happened in test results.The reflection coefficient is lower than-5dB in the range of 94.3GHz-99.6GHz,and the sensitivity of the detection voltage in the whole band of 95GHz-99 GHz is higher than 5000mV/mW,the highest is 6200mV/mW;and the tangent sensitivity is about-57 dBm while the video bandwidth is 1.2kHz,which meet the requirement of high sensitivity.The highest sensitivity of the detection voltage of D band detector is about 2000mV/mW,but performance degradation is obvious in the high frequency range of D band,the sensitivity of the detection voltage in the band of 130GHz-170 GHz is about 400mV/mW,and the tangent sensitivity is about-37 dBm at 110 GHz while the video bandwidth is 1.2kHz.