When chirp pulse compression technology (PCT) is applied in Electromagnetic Acoustic Transducers (EMATs), the frequency response characteristic of the EMAT testing system may be inconsistent with the chirp signal bandwidth. Furthermore, it causes a loss in the frequency spectrum and distortion of the ultrasonic echo waveform, leading to a decrease in the signal-to-noise ratio (SNR) and range resolution of the pulse compressed signal. To solve this problem which has not been further researched in the previous publications, we proposed a new circuit-field coupling finite element model for ultrasonic wave generation of the spiral coil EMAT for enhancing the pulse compression effect, and the excitation circuit for the EMAT is also considered in this model. Furthermore, the effects of the diameter of the spiral coil wire, matching method of the impedance matching network, and parameter of the matching components on the peak and width of the main lobe after pulse compression were analysed through simulations and experiments. Subsequently, the optimal combination of the EMAT coil conductor diameter, impedance matching method, and matching component parameters were determined and verified by experiments. The results show that the SNR and range resolution of the pulse compressed ultrasonic signal can be largely enhanced when the diameter of the spiral coil wire, impedance matching method, and the parameter of the matching components are chosen carefully. When the aforementioned parameters are appropriately selected, the amplitude of the main lobe can be increased 3.16 times, and the width of the main lobe is reduced by 31.7%.

当在电磁声换能器（EMAT）中应用线性调频脉冲压缩技术（PCT）时，EMAT测试系统的频率响应特性可能与线性调频信号带宽不一致。此外，它会导致频谱损失和超声回波波形失真，从而导致信噪比（SNR）和脉冲压缩信号的距离分辨率降低。为了解决以前的出版物中未作进一步研究的问题，我们提出了一种新的电路场耦合有限元模型，用于产生螺旋线圈EMAT的超声波，以增强脉冲压缩效果，并且EMAT的激励电路为在此模型中也考虑了。此外，螺旋线圈线的直径的影响，通过仿真和实验分析了阻抗匹配网络的匹配方法，以及脉冲压缩后主瓣的峰和宽上的匹配分量参数。随后，确定并通过实验验证了EMAT线圈导体直径，阻抗匹配方法和匹配组件参数的最佳组合。结果表明，精心选择螺旋线圈线的直径，阻抗匹配方法和匹配元件的参数，可以大大提高脉冲压缩超声信号的信噪比和距离分辨率。当上述参数被适当地选择，主瓣的幅度可以增加3.16倍，而主波瓣的宽度是由31.7％降低。通过仿真和实验分析了脉冲压缩后主瓣波峰和宽度上匹配分量的参数和参数。随后，确定并通过实验验证了EMAT线圈导体直径，阻抗匹配方法和匹配组件参数的最佳组合。结果表明，精心选择螺旋线圈线的直径，阻抗匹配方法和匹配元件的参数，可以大大提高脉冲压缩超声信号的信噪比和距离分辨率。当上述参数被适当地选择，主瓣的幅度可以增加3.16倍，而主波瓣的宽度是由31.7％降低。通过仿真和实验分析了脉冲压缩后主瓣波峰和宽度上匹配分量的参数和参数。随后，确定并通过实验验证了EMAT线圈导体直径，阻抗匹配方法和匹配组件参数的最佳组合。结果表明，精心选择螺旋线圈线的直径，阻抗匹配方法和匹配元件的参数，可以大大提高脉冲压缩超声信号的信噪比和距离分辨率。当上述参数被适当地选择，主瓣的幅度可以增加3.16倍，而主波瓣的宽度是由31.7％降低。