ATS-5X User Manual
Page 43 of 44
5
Abbreviations
Term
Long Form
Explanation
dB
Decibel
A way of expressing a ratio, typically a power ratio. A decibel
calculation for P
1
as compared to P
2
is shown below:
Ratios of quantities other than power are typically expressed in the
following manner:
dBm
Decibel with reference to 1
Milliwatt of power
A measure of power. When a device like the ATS-5X measures voltage
only, reference impedance is assumed, such as 600Ω. Power expressed
in dBm is calculated from the RMS voltage as follows:
Where Z
REF
is the reference impedance for the circuit.
dBrn
Decibel above Reference Noise
A measure of power. Power expressed in dBrn is related to power
expressed in dBm as follows:
dBrnC
Decibel above Reference Noise
with C-message filter
The same dBrn except that the RMS voltage measurement for the dBm
calculation
DFT
Discrete Fourier Transform
A method of calculating a frequency spectrum from time domain data.
DTMF
Dual Tone Multiple Frequency
Type of signaling digit that is composed of two simultaneous tones.
HID
Human Interface Device
This is a popular type of communication standard (or device class) for
USB mouse and keyboard devices
Hz
Hertz
A measure of frequency. A 1004 Hz tone is an oscillatory waveform
with a rate of 1004 repetitions per second
IMD
Inter-modulation Distortion
When multiple tones are present in a circuit, nonlinear distortion can
cause other tones at multiples of the base tones
kHz
Kilohertz
A measure of frequency. 1 Kilohertz = 1,000 Hertz
mA
Milliampere
A measure of electric current. 1 Milliampere = 10
-3
Ampere
ms, msec
Millisecond
A measure of time. 1 Millisecond = 10
-3
Second
P/AR
Peak-to-Average Ratio
The ratio between the peak value of a signal and its average. The ATS-
5X P/AR measurement performs this measurement on the absolute
value of the receive signal.
ppm
Parts Per Million
A measure of ratio. 1 ppm = 10
-6
