Gainfaktor

Gainfaktor, in electronics and signal processing, denotes the ratio by which a system increases the amplitude of a signal. In linear systems the gain is a dimensionless quantity, often represented as Av (voltage gain), Ai (current gain) or Ap (power gain). When the system is described in terms of transfer function H(jω), the magnitude |H(jω)| is the gain at frequency ω. In many contexts, gain is expressed in decibels: GdB = 20 log10|H| for voltage or 10 log10|H|^2 for power.

Real systems may exhibit frequency dependence, so the gain varies with signal frequency. The gain can be specified as a single value for a particular operating point, or as a bandwidth-limited function. In practice, the gain is often analyzed in conjunction with phase response and bandwidth to assess overall system performance. For power considerations, the power gain is the ratio of output to input power, which relates to the square of voltage or current gains under fixed impedance conditions.

Applications include audio and RF amplifiers, sensor preamplifiers, and other signal-conditioning stages. In control systems, a proportional gain K determines how strongly the controller responds to error signals; high gain improves response speed but can reduce stability and introduce oscillations if not properly tuned. In data acquisition, gain factors are used to scale sensor outputs to usable ranges and to optimize resolution.

Related terms include amplification factor, transfer gain, and decibels. The term gainfaktor is commonly used in German-language technical literature to denote the same concept.