宽带接地共面波导的时域测量方法研究

Research on Time Domain Measurement Method of Broadband Grounded Coplanar Waveguides

宽带接地共面波导是校准示波器宽带探头的核心器件。为了准确测量示波器探头的带宽指标,获得宽带接地共面波导传输特性成为实现高精度校准的关键。运用时域自动网络分析仪的测量原理,基于飞秒激光激励皮秒电脉冲技术,采用二次测量法,构建了接地共面波导二次时域测量系统,通过两次测量的方式解算出宽带接地共面波导的冲激响应,从而得到频域带宽指标。以阵列通孔结构仿真设计接地共面波导,采用二次测量法测量加工样品,3 dB带宽达54.2 GHz,与仿真结果相比具有较好的一致性。定标后的宽带接地共面波导可以作为标准器件,用于示波器宽带探头的校准,其测量结果可有效溯源至脉冲波形参数国家基准。

The broadband grounded coplanar waveguide(GCPW)is the core component for calibrating oscilloscope broadband probes.To accurately measure the bandwidth of the oscilloscope probe,obtaining the transmission characteristics of the broadband GCPW becomes the key to achieving high-precision calibration.A GCPW time-domain twice measurement system is constructed based on femtosecond laser excitation picosecond electric pulse technology in the measuring principle of time-domain automatic network analyzer(TDANA).This involves taking two measurements in the system to solve the impulse response of the broadband GCPW(twice measurement method),thereby the frequency domain bandwidth can be obtained.The GCPW is designed with a post-wall structure(vias placed along the signal trace),and the processed sample is measured by the twice measurement method.In this way,the 3 dB bandwidth of our sample reaches 54.2 GHz,which greatly agrees with the simulation result.The calibrated broadband GCPW can be used as a standard device for calibrating broadband probes,and its measured results can be effectively traced to the national benchmark for pulse waveform parameters.