Impedanssihäiriöt

Impedanssihäiriöt, known in English as impedance mismatches, refer to a phenomenon that occurs when the electrical impedance of a transmission line or a component does not match the impedance of the source or load. Impedance is a measure of the opposition to alternating current flow in a circuit. When impedances are not matched, part of the signal's energy is reflected back towards the source instead of being fully transmitted to the load.

This reflection causes several undesirable effects. The most significant is signal loss, as not all the power is delivered to the intended destination. Reflections can also lead to signal distortion, creating echoes or ringing that can interfere with the integrity of the data being transmitted. In high-frequency applications, such as radio frequency (RF) and microwave systems, impedance mismatches can cause significant power loss and even damage to sensitive components due to reflected power.

Impedance mismatches can arise from various sources, including incorrect component selection, variations in cable lengths, poor connector quality, or circuit design flaws. The measurement of standing wave ratio (SWR) or return loss is commonly used to quantify the degree of impedance mismatch in a system. Proper impedance matching is crucial for efficient power transfer and signal integrity in many electronic and communication systems. Techniques for achieving impedance matching include the use of matching networks, transformers, and careful selection of transmission line characteristics.