What is return loss in VSWR?

Return Loss is the portion of a signal that is lost due to a reflection of power at a line discontinuity. Return Loss is similar to VSWR and is generally preferred in the cable industry to a VSWR specification. Since it is a logarithmic measurement, it is very useful when displaying very small reflections.

How is return loss calculated?

What is Return Loss? The measurement of the amount of light reflected back toward the source is called return loss, and it is expressed in decibels (dB). This measurement parameter is always a positive number, and a high return loss is a favorable measurement parameter that generally correlates to a low insertion loss.

How do you calculate VSWR?

The VSWR definition states that the VSWR is equal to the maximum voltage on the line divided by the minimum voltage. The voltage fluctuations come about as a result of the voltage components from the forward power and the reflected power summing together.

What is a good return loss?

While different systems have different acceptable return loss limits, 15 dB or better is a common system limit for a cable and antenna system. The return loss scale is normally set up from 0 to 60 dB with 0 being an open or a short and 60 dB would be close to a perfect match.

Is lower return loss better?

Return loss is a measure of how well devices or lines are matched. A match is good if the return loss is high. A high return loss is desirable and results in a lower insertion loss.

What does a VSWR of 2 mean?

A VSWR value under 2 is considered suitable for most antenna applications. The antenna can be described as having a “Good Match”. So when someone says that the antenna is poorly matched, very often it means that the VSWR value exceeds 2 for a frequency of interest.

What causes return loss?

What Causes Return Loss? There are two major causes of RL in a network: discontinuities and impedance mismatches. Discontinuities occur at connections where cable is terminated to plugs or jacks and within the plug/jack connection itself. Impedance mismatches can be macro or micro in scale, and both are important.

What causes bad VSWR?

However, there are applications where more than 2:1 can be seen. High VSWR is often due to testing with very broadband, high-power, and poorly matched loads. Higher VSWR levels are a sign of a poor setup.

What is a bad return loss?

If the return loss is 10 dB, 10% of the power is returned. While different systems have different acceptable return loss limits, 15 dB or better is a common system limit for a cable and antenna system.

What is return loss in antenna?

Antenna Return loss is the amount of the power reflected from the input of an antenna when excited by 1 Watt. Thus, 1- RL, which is the relative transmitted power in to the antenna shows the quality of the matching.

What is return loss?

Return loss. In telecommunications, return loss is the loss of power in the signal returned/reflected by a discontinuity in a transmission line or optical fiber.

What is input return loss?

Return loss tells you how much of the input signal is reflected. Return loss is the ratio between the reflected power and input power: If the input signal is 0 dBm and there is 25 dB return loss, then the component will create a reflected wave of -25 dBm back toward the generator.