Attenuator
An attenuator scales a signal down by a set number of decibels, at every frequency. It brings a generator's level down to what a modulator wants.
Ports
One input, in, and one output, out.
The model
For an attenuation \(A\) (dB), every part of the signal is scaled by
\[g = 10^{-A/20},\]the DC and each tone by \(g\), and the noise density by \(g^2\). It passes volts or amps alike.
Settings
| Field | Default | Meaning |
|---|---|---|
db | 10 | Attenuation (dB) |
From the tool's own tables, file format version 1: the names are those in a .jekray file.
Readouts
The panel gives its output in the steady state: the DC level, the five strongest tones (each one’s amplitude, rms and the phase of its cosine), and the noise, as a density at 1 kHz and in rms from 1 Hz to 1 GHz. Any notes, such as an input left unwired, are listed under it.
Assumptions
- Flat in frequency and noiseless: a real resistive attenuator adds the Johnson noise of its resistance.
Related
- Amplifier.
- Summing junction, whose gains can scale too.