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How to Get Rid of High Frequency Noise

Noise is an unwanted signal that is forced on a signal being used. It causes fluctuations in the signal, such as popping and hissing, or white spots in televisions. It can be caused by interference from electronic components or devices. For example, wireless devices such as keyboards and mice must be adjusted because of interference from cell phones and other wireless devices. Noise is also transmitted through power lines.

High frequency noise is usually in the radio frequency range. This is because radio signals are commonly used in wireless communications. To get rid of high frequency noise, use filters made from electrical components or circuits.

Things You'll Need

Capacitor
Resistor
Inductor
741 op amp
Circuit
Basic electronics textbook

Instructions

- 1
  Place a low frequency tantalum capacitor at the input lead of the component of interest. The capacitor value can be from 0.01 to 1.0 microfarads. Mini-speakers and integrated circuit components such as op amps use capacitors this way.
- 2
  Place a capacitor at the component's output, instead of the input. Some components may also require capacitors at both the input and output. Noise can be reduced in components such as linear ICs, which are voltage regulators, by adding capacitors to two leads. A 0.1uF capacitor placed across a Hall effect sensor's supply and ground leads helps to control noise.
- 3
  Use a choke inside the circuit, as another option. A choke is an inductor specially designed to block radio frequency signals. Inductors are coils of wire wrapped around metal. Chokes are found in power supplies, cell phones and radios.
- 4
  Add a low-pass filter to the circuit, instead. Low-pass filters are so called because they pass low frequency signals and block higher ones. To build one, combine a resistor and capacitor. A low-pass filter can also be built using a resistor, capacitor and op amp. The resistor and capacitor are attached to the op amp's pin 2 or 3.

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