What is near-field measurement?

In the near-field measurement process the radiated field distribution of the AUT is measured in the radiating near field in two polarizations. The near-field transformation algorithm relates the measured field values to the amplitudes of the equivalent sources, which are then determined in an inverse process.

What are the types of gain measurement of an antenna?

* Antenna gain is measured in decibels as either dBi or dBd. dBi refers to dB away from a theoretical isotropic antenna (0), while dBd refers to dB away from a more real world reference dipole antenna with a gain of 2.15 dB. RF Venue uses dBd because we find it to be a more meaningful measurement.

What is two antenna method?

The two-antenna method requires two identical test antennas, one used as a transmitter and the other one used as a receiver. Both the antennas must be well matched in terms of impedance and polarization. The main disadvantage of this method is that it is difficult to find two antennas of identical gains.

What is near field and far field in antenna?

Electromagnetically short antennas For such an antenna, the near field is the region within a radius r ≪ λ, while the far-field is the region for which r ≫ 2 λ. The transition zone is the region between r = λ and r = 2 λ .

What is near field diffraction?

In optics, the Fresnel diffraction equation for near-field diffraction is an approximation of the Kirchhoff–Fresnel diffraction that can be applied to the propagation of waves in the near field.

What is near field range testing?

The near-field antenna test range is a very compact and advanced antenna measurement facility. In an anechoic chamber, antennas and antenna systems can be analysed by measuring the electromagnetic near-field by a moving probe.

What is near field technique?

The near field is a region in which there are strong inductive and capacitive effects from the currents and charges in the antenna that cause electromagnetic components that do not behave like far-field radiation. These effects decrease in power far more quickly with distance than do the far-field radiation effects.

What is the breakpoint between near field and far field?

Radiative Near Field: This region is also known as the Fresnel Region. It is the region between the reactive near field and the far field.

What is near field radiation?

What is the sample near-field data for slot array antenna antenna?

Sample Near-Field for Slot Array Antenna Near-field Phase along y=0 centerline Phase (deg) X (in) -180 -150 -120 -90 -60 -30 0 30 60 90 120 150 180 Sample Near-Field Data Main Component Phase

What is the theoretical basis for planar near field measurements?

Theoretical Basis for Planar Near -field Measurements lScattering Matrix Theory Developed by Dr. D. M. Kerns in 1960’s lDoes NotRequire: lIdeal Probe, measuring one component of field at a point lReciprocal antennas

What is the time convention for near-field theory?

Time Convention Phase increases with +z Consistent with published papers on Near -field Theory Time convention in instrumentation and NSI software is Phase decreases with +z. e-itw e+jtw Only affects complex quantities such as conversion from linear to circular components -iωt convention +jωt convention 2 xy R EiE E – = 2 xy R EiE E

What is the sample near field data for Ne nearfield systems?

NEARFIELD SYSTEMS, INC. Sample Planar Near-field Data -50 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 -7.5 -5.0 -2.5 0.0 2.5 5.0 7.5 Sample Near-Field for Slot Array Antenna Near-Field Amplitude along y=0 centerline Amplitude (dB) X (in)