CAJ | 학술논문

设计了一种基于正交调制原理的数字频率特性测试仪，系统用稳态响应法测量电路的频率特性．单片机作为主控芯片，完成系统的总体控制及数字信号处理；使用集成的直接数字频率合成芯片输出全频率范围内的正弦波．系统对待测电路的输入信号及其输出响应采样，经数字信号处理后，获得电路的幅频特性和相频特性．设计的测试仪测某RLC 网络，中心频率的相对误差小于0?2％，有载品质因数相对误差小于1?25％，最大电压增益大于－1 dB．频率特性测试仪输入输出阻抗均为50Ω，幅频误差绝对值小于0?5 dB，相频误差绝对值小于3°，测试仪能满足微机械谐振传感器特征参数测试需求．
설계료일충기우정교조제원리적수자빈솔특성측시의，계통용은태향응법측량전로적빈솔특성．단편궤작위주공심편，완성계통적총체공제급수자신호처리；사용집성적직접수자빈솔합성심편수출전빈솔범위내적정현파．계통대대측전로적수입신호급기수출향응채양，경수자신호처리후，획득전로적폭빈특성화상빈특성．설계적측시의측모RLC 망락，중심빈솔적상대오차소우0?2％，유재품질인수상대오차소우1?25％，최대전압증익대우－1 dB．빈솔특성측시의수입수출조항균위50Ω，폭빈오차절대치소우0?5 dB，상빈오차절대치소우3°，측시의능만족미궤계해진전감기특정삼수측시수구．
A digital frequency characteristic analyzer based on orthogonal modulation principle is developed using steady?state response measurement method.The frequency response analyzer consists of Direct Digital frequency Syn?thesis(DDS),analog multiplier,low pass filter,and low power consumption MCU.The MCU is employed as main control unit to carry out overall control and digital signal processing.The sine wave over the full frequency range is output through the integrated DDS chip.The analyzer system samples and digitalizes the input signal and output re?sponse,hence the amplitude and phase frequency characteristics are obtained.An RLC network is chosen to test the frequency characteristic analyzer.Measurement results show that the center frequency error is not more than 0?2%, the absolute value of quality factor error is less than 1?25%,and the maximum voltage gain is larger than -1 dB. Both the input and output impedance of the frequency characteristic analyzer are 50 Ω,and the absolute value of measurement errors are less than 0?5dB and 3 ° for amplitude frequency and phase frequency,respectively.The ana?lyzer is suitable for characteristic parameter measurement of micromechanical resonant sensor.