Antenna FundamentalsGain, directivity, beamwidth and polarisation, and how the four constrain each other.Electrical EngineeringAn antenna trades a guided wave for a radiated one; gaindescribes how sharply it concentrates power.HALF-WAVE DIPOLE2.15 dBiISOTROPIC RADIATOR0 dBi by definition20 DBI ANTENNABeamwidth near 18°Gain is directivity reduced by efficiencyEffective aperture and gain rise togetherBeamwidth narrows as gain increasesReciprocity: the pattern is the same either wayPolarisation mismatch loses signal outrightWide bandwidth usually costs gainLOOK FOR ITA dish's gain rises with the square of its diameter and with the square offrequency.dBi is referenced to an isotropic radiator, dBd to a half-wave dipole.They differ by 2.15 dB and are often quietly mixed up.Antenna Fundamentalslearnposters.com
Antenna Fundamentals — printable engineering wall chart from LearnPosters. Free vector PDF, US Letter and A4.

What’s on the Antenna Fundamentals poster

A definition and 6 facts worth remembering.

An antenna trades a guided wave for a radiated one; gain describes how sharply it concentrates power.

dBi is referenced to an isotropic radiator, dBd to a half-wave dipole. They differ by 2.15 dB and are often quietly mixed up.

Questions about the Antenna Fundamentals poster

What’s on the Antenna Fundamentals poster?
A definition and 6 facts worth remembering. An antenna trades a guided wave for a radiated one; gain describes how sharply it concentrates power. Gain is directivity reduced by efficiency; Effective aperture and gain rise together; Beamwidth narrows as gain increases; Reciprocity: the pattern is the same either way; Polarisation mismatch loses signal outright; Wide bandwidth usually costs gain; Half-wave dipole — 2.15 dBi; Isotropic radiator — 0 dBi by definition; 20 dBi antenna — Beamwidth near 18°; A dish's gain rises with the square of its diameter and with the square of frequency.. dBi is referenced to an isotropic radiator, dBd to a half-wave dipole. They differ by 2.15 dB and are often quietly mixed up.
Who is the Antenna Fundamentals poster for?
Antenna Fundamentals belongs to the Electrical Engineering section rather than to a school year, because engineering is not something one grade owns. Anyone learning electromagnetics can pin it up — a beginner, a student mid-course, or someone revising years later.
When should you use the Antenna Fundamentals poster?
Read it before comparing two antenna datasheets, especially their gain references. A wall chart earns its place by being glanceable from where the work is happening, so Antenna Fundamentals belongs on the wall where that engineering work actually happens, within glancing distance, rather than filed away.
What other posters go with Antenna Fundamentals?
Antenna Types, Boundary Conditions and Link Budget sit alongside Antenna Fundamentals in the Electrical Engineering section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Antenna TypesBoundary ConditionsLink Budget
Is the Antenna Fundamentals poster free to download and print?
Yes. Antenna Fundamentals downloads as a free PDF with no account, no email and no watermark, like everything else in the Electrical Engineering section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
What size does the Antenna Fundamentals poster print at?
Antenna Fundamentals is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of Antenna Fundamentals loses nothing.Printing guide

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