What is antenna polarization?
The polarization of an antenna is the polarization of the wave it radiates in a given direction: the figure traced over time by the tip of the electric-field vector at a fixed point, observed along the direction of propagation.[1] It may be linear, circular (right- or left-hand) or, in general, elliptical, and mismatched polarization between two antennas causes polarization loss.[2]
What kinds of polarization are there?
- Linear: E oscillates along a line, e.g., vertical or horizontal dipoles.
- Circular: two orthogonal, equal-amplitude components in 90° phase quadrature; the vector rotates at constant magnitude. IEEE defines right-hand as clockwise rotation viewed in the direction of propagation.[1]
- Elliptical: the general case, characterized by axial ratio, tilt angle and sense.
What is the polarization loss factor?
The polarization loss factor is PLF = |ρ̂w·ρ̂a|², where ρ̂ are the unit polarization vectors of the incoming wave and the receiving antenna.[2] For two linear antennas misaligned by angle ψ, PLF = cos²ψ: 45° costs 3 dB and 90° is in theory infinite (in practice 20–30 dB due to cross-polarization). A linear antenna receiving circular polarization loses 3 dB; RHCP received by LHCP is ideally rejected completely.
What is cross-polarization?
Cross-polarization is the component orthogonal to the intended (co-) polarization. Ludwig’s third definition is the standard for measuring it in patterns of horns and reflector feeds.[3] Cross-polar discrimination (XPD) matters for dual-polarized links and MIMO, where two orthogonal polarizations carry independent streams.
Which polarization is used where?
Vertical polarization dominates VHF/UHF mobile and broadcast-to-mobile links; horizontal is common for terrestrial TV in many regions; GNSS uses RHCP; many satellite services use circular to avoid Faraday rotation problems below about 10 GHz; cellular base stations commonly use ±45° slant dual polarization for diversity.[4][5]
Frequently asked questions
Does polarization matter indoors?
Less than outdoors: multipath scatters polarization, so linear-to-linear mismatch is often a few dB rather than 20 dB.
What is Faraday rotation?
Rotation of a linearly polarized wave’s plane as it passes through the ionosphere in Earth’s magnetic field, significant at VHF and L-band.
What is slant ±45° polarization?
Two orthogonal linear polarizations tilted ±45° from vertical, used for polarization diversity.
See also
References
Online sources accessed October 21, 2026; printed works cited by edition. See all sources.
- “IEEE Standard for Definitions of Terms for Antennas (IEEE Std 145-2013)”. IEEE Antennas and Propagation Society. 2014.
- “Antenna Theory: Analysis and Design, 4th ed.”. C. A. Balanis, Wiley. 2016.
- “The Definition of Cross Polarization”. A. C. Ludwig, IEEE Transactions on Antennas and Propagation, vol. 21, no. 1, pp. 116-119. January 1973.
- “Satellite Communications Systems, 5th ed.”. G. Maral and M. Bousquet, Wiley. 2009.
- “Antennas and Propagation for Wireless Communication Systems, 2nd ed.”. S. R. Saunders and A. Aragón-Zavala, Wiley. 2007.