67 GHz宽带谐波相位参考及其定标技术

作为非线性矢量网络分析仪的重要参考测量通道,谐波相位参考能够提供多频点、多波量以及复频率下的绝对相位测量能力。设计了基于共面波导非线性传输线方案的原型谐波相位参考样机,并提出了基于EOS光电采样系统的完整谐波相位参考定标技术,主要包括时基失配、平均去噪、相位对准、连接器失配与示波器复频率响应修正等流程。定标实验结果表明,原型样机能够在1 GHz功率27 d Bm信号激励下输出半峰值脉宽为22 ps的周期脉冲序列,其频带覆盖范围超过67 GHz,并在超高次谐波频点上拥有小于±10°的相位精度与小于±5°的相位可重复性。最后将原型样机装配到非线性矢网中,通过测量2 GHz信号激励下超窄时域脉冲发生器的输出时域信号,并将之与采样示波器测量结果进行比对,结果证实了谐波相位参考设计与定标技术的有效性与正确性。

Realization and calibration for 67GHz wideband harmonic phase reference

As the most important measurement channel of nonlinear vector network analyzer (NVNA), the harmonic phase reference (HPR) can provide the ability of measuring the absolute phase information for the multi frequency situations. A prototype HPR based on the nonlinear transmission lines (NLTLs) is designed. The complete phase calibration procedure for 67GHz wideband HPR is also proposed, including the time base distortion, the average de noising, the phase alignment, the connector mismatch and the frequency response corrections. The calibration experiment results show that, an impulse sequence with pulse width less than 22 ps and 67 GHz frequency bandwidth is obtained, where the prototype HPR was excited by a 1 GHz sinusoidal signal with 27 dBm input power. Moreover, the phase accuracy and repeatability are less than ±10° and ±5° degree in the highest harmonic components, respectively. Finally, the comparison results between NVNA based (with prototype HPR) and oscilloscope based measurement, for the output time domain waveform of the narrow time width pulse generator under a 2 GHz signal exciting, prove that the validity and efficiency of the proposed realization and calibration techniques.