Bird Technologies AT-500-Manual - Manual (Page 38)

Bird AT-500 Antenna Tester
20
Figure 6 Single Frequency
Measurement Units
Rho (Reflection Coefficient), VSWR (Voltage Standing
Wave Ratio), Match Efficiency (%), and Return Loss
(dB), are different units of measurement that can be
used to present the same information. (Similarly, Cel-
sius and Fahrenheit are different units of measure-
ment used to express the same temperature). These
units can be used to express the degree of match
between an antenna system and a transceiver.
Rho
Rho is the ratio of reflected wave voltage to forward
wave voltage. A perfect antenna would not have any
reflected waves, hence would have a 0.00 reflection
coefficient.
VSWR
VSWR refers to the ratio of maximum and minimum
voltages that are set up on a transmission line result-
ing from the combination of a forward wave and
reflected wave. If the antenna system is perfectly
matched, the VSWR would be 1:1 and shown as 1.00.
VSWR
1.2 1.5
1.35
69.00 MHz
Freq
MHz Units Manual
Scale Auto
Scale Audio
Off