| 摘要 |
<p>An apparatus for measuring the intensity of an interfering electromagnetic wave, specifically for measuring the average value of impulsive noises in a short time accurately. In the apparatus, impulsive noises, inputted through a variable attenuator (12), a frequency converter (13), an intermediate-frequency amplifier (15), a band-pass filter (16) of 9 KHz or 120 KHz are inputted into a linear detector (17). The detected outputs are passed through a low-pass CR filter (31) whose cut-off frequency is tens of thousands of hertz to lower their peak values and to widen their width. The output of the filter is converted into digital signal by an A/D converter (33), and digital values at respective sampling points in one frame of the digital signals are summed by a computing circuit (34). Then, the summation value thereof is divided by the number of samples to obtain the average value and the result is displayed.</p> |
