What is meant by antenna efficiency?

According to the standard definition, “Antenna Efficiency is the ratio of the radiated power of the antenna to the input power accepted by the antenna.” Simply, an Antenna is meant to radiate power given at its input, with minimum losses.

What is antenna efficiency and gain?

Antenna Gain is the ratio of power transmitted in a certain direction with a specific reference point. Relation between gain and efficiency is G = e x D where D is the directivity and E if the efficiency Antenna efficiency is how much RF power delivered to the antenna (from radio) is actually transmitted into the air.

What is antenna efficiency measured in?

The antenna efficiency is measured in an anechoic chamber by feeding some power to the antenna feed pads and measuring the strength of the radiated electromagnetic field in the surrounding space. A good antenna, in general, radiates 50 – 60 % of the energy fed to it (-3 to -2.2dB).

What affects antenna efficiency?

A high efficiency antenna has most of the power present at the antenna’s input radiated away. A low efficiency antenna has most of the power absorbed as losses within the antenna, or reflected away due to impedance mismatch.

How is antenna efficiency percentage calculated?

Directivity and Gain are typically expressed in dBi, and efficiency is typically expressed as a percentage. First you need to convert from dBi to power [ i.e., 10^( gain / 10 ) ]. Then efficiency is the ratio of gain to directivity. In your case, efficiency = ( 7.4 / 8.9 ) which is approximately 0.83, or 83%.

How can I increase my antenna efficiency?

If concern is antenna efficiency then material losses (copper or dielectric losses) are an important factor. You can apply reflecting surfaces, active component, EBG structure or slot matching etc to improve radiation efficiency.

How is antenna radiation efficiency measured?

Measurement Setup and Procedure

  1. Measure the power supplied to the antenna using a power meter or a receiver.
  2. Measure the antenna reflection coefficient using a VNA.
  3. Calculate the power accepted by the antenna using Eq.
  4. Measure the E field in 3D at a fixed distance.
  5. Calculate the total radiated power using Eq.

What is antenna dBi?

The expression dBi is used to define the gain of an antenna system relative to an isotropic radiator at radio frequencies . The symbol is an abbreviation for “decibels relative to isotropic.” The dBi specification is based on the decibel , a logarithm ic measure of relative power .

How is antenna radiation efficiency calculated?

The radiation efficiency of an antenna is defined as the ratio of the outward radiated power by the antenna to the input power fed to the excitation port of the antenna. The power loss due to the port impedance mismatch is not considered here. For ideal lossless antenna, the radiation efficiency ( η r ) is 1.