用于大功率超声的电缆传输特征的实验研究

大功率超声电信号通过特种电缆传输时,其电流损耗比较大。为了解决该电信号的长距离传输问题,用4294A阻抗分析仪对单芯同轴电缆进行了有针对性的测试。通过改变电缆的负载电阻,获得了一系列电缆的输入阻抗随频率的变化曲线。当负载电阻比较小时,在一些特定的频率处,电缆的输入阻抗很大。这时,其电功率传输效率很低。当负载电阻比较大时,电缆的输入阻抗取极大值的频率位置发生改变。借助于电磁波在电缆负载端的反射和透射特征,分析了这些实验结果,探讨了这些实验结果对大功率超声电功率传输特征的影响,最后结合实验结果给出了大功率超声传输电缆的设计原则。

Experimental research on the transmission characteristics of high power ultrasonic cable

When the high power ultrasonic electrical signal is transmitted via special cable, the power loss is relatively large. To solve the long distance transmission problem of high power ultrasonic electrical signal, the 4294A impedance analyzer is used to do a more detailed test for single core cable. By changing the load resistance of the cable, a series of curves which describe the differences of input impedance changing with frequency are obtained. When the load resistance is relatively low, the input impedance of the cable is very high at some specific frequencies. Then the transmission efficiency of the power is very low. While the load resistance is relatively great, the position of frequency, at which the input impedance of the cable reaches the maximum, changes. With the aid of the reflection and transmission characteristics of electromagnetic wave at the load end of the cable, the results of these experiments are analyzed in detail, and the influence of these experiments on the transmission characteristics of the high power ultrasonic power is discussed. Finally, according to the experimental results, the design principles of the high power ultrasonic transmission cable are brought out.