High Frequency Signals & BNC Cables: Explained

[cks]

Hihi,

I don't understand what is the meaning that BNC cable transfer high frequency signal?

For example, I use BNC cable for the connection between my diode controller to the diode laser. I also use BNC cable to connect my photodiode to the oscilloscope.

I'm not sure what is the meaning of high frequency signal here? Is the signal transmitting has high frequency? but the voltage to my diode is a direct current, so where comes the frequency?? a bit confused.

I know the BNC cable can shield away from picking up radio signal and antennas from somewhere else, but what is high frequency mean here? Can it transmit low frequency?

 

[berkeman]

Coax can be used from DC to its cutoff frequency, although its loss can be significant well before its cutoff frequency.

Twisted pair makes a fine transmission line too, but does not have the self-shielding feature of coax.

 

[oswaler]

I can provide some clarification on the concept of high frequency signals and BNC cables.

Firstly, let's define what high frequency signals are. In simple terms, high frequency signals refer to any signals with a frequency above 20 kHz. This can include radio waves, microwaves, and even visible light.

Now, let's look at how BNC cables come into play. BNC (Bayonet Neill–Concelman) cables are a type of coaxial cable that are commonly used in electronic equipment for transmitting high frequency signals. These cables are designed to have a low impedance and high shielding to minimize signal loss and interference.

In your example, the BNC cable is being used to connect your diode controller to the diode laser and your photodiode to the oscilloscope. In both cases, the signals being transmitted are high frequency signals. The diode controller is sending a high frequency signal to control the diode laser, while the photodiode is receiving a high frequency signal from the oscilloscope.

You may be wondering why high frequency signals are used in these applications. High frequency signals have the advantage of being able to carry more information and travel longer distances without losing their quality. In the case of your diode controller and diode laser, the high frequency signal is necessary to precisely control the laser output. And in the case of the photodiode and oscilloscope, the high frequency signal allows for accurate measurement of the signal being received.

To address your question about the voltage to your diode being a direct current, it is true that the voltage is a direct current. However, the signal being transmitted through the BNC cable is not just the voltage. It also includes variations in the voltage, which is what we refer to as the frequency.

In conclusion, high frequency signals are an important aspect of many electronic applications, and BNC cables are specifically designed to handle these signals efficiently. I hope this explanation helps to clarify the concept for you.