Hi, I need to to the following exercise:
Estimate the measured rise time when connecting a 10kHz square signal, with an output impedance of 1 kΩ, to the oscilloscope using a coaxial cable.
I know that Rise time = 0.35/BW, but I don't know how can I find the Bandwidth of a square signal when it is supposed to be infinite.
Thanks!
The bandwidth is the bandwidth of the oscilloscope's front end. Since you are estimating, use 10Mhz.
Thanks!
To estimate the rise time when connecting a 10kHz square signal to an oscilloscope using a coaxial cable, you need to consider the bandwidth limitations of the system. Although the bandwidth of a square signal is theoretically infinite, real-world systems have limitations that affect the rise time.
To find the bandwidth of the system, you can start by examining the coaxial cable's specifications. Look for the cable's rated bandwidth, which is generally specified in the datasheet or technical documentation. It represents the maximum frequency that the cable can effectively transmit without significant distortion.
If the cable's bandwidth is not readily available, you can try estimating it by considering the length and type of the coaxial cable. Different types of cables have specific characteristics that affect their bandwidth. For instance, coaxial cables with thicker conductors or higher-quality shielding may have a higher bandwidth.
Once you have determined the cable's bandwidth, you can use it in the formula you provided: Rise time = 0.35/BW. Since the rise time calculation depends on the bandwidth value, you need to obtain a reasonable estimate for it. Keep in mind that this estimate may not be entirely accurate, but it can still provide a rough approximation of the rise time considering the system's limitations.
Remember that this estimation assumes that the rest of the system, including the oscilloscope and other signal conditioning components, do not introduce significant limitations to the signal bandwidth.