AntennasGainRadiation PatternBeamwidth

Antenna Radiation Patterns and Gain

Every antenna has a personality — some broadcast in all directions like a light bulb, others focus like a flashlight. The radiation pattern shows you where the signal goes.

Interactive Radiation Pattern
Select an antenna type to see its 2D polar radiation pattern. The radius at each angle represents the relative field strength.
0°45°90°135°180°225°270°315°-12 dB-6 dB-3 dBHalf-wave dipole — 2.15 dBi

Gain

2.15 dBi

Beamwidth (HPBW)

78° (E-plane)

Front-to-back ratio

0 dB (bidirectional)

Typical use

Base stations, dipole arrays

Antenna Pattern Fundamentals

Antenna Type Quick Reference
Isotropic0 dBi
HPBW: 360° × 360°
Theoretical only; used as reference. No physical realisation.
Half-wave Dipole2.15 dBi
HPBW: 78° (E-plane)
Practical reference. Bidirectional figure-8 pattern. Foundation of Yagi, collinear, and log-periodic designs.
Yagi-Uda6–16 dBi
HPBW: 40–70°
TV, amateur radio, point-to-point links. Gain increases with more elements; used as LPDA for wide bandwidth.
Parabolic Dish20–60 dBi
HPBW: 0.1°–5°
Satellite ground stations, radio astronomy, microwave backhaul. Gain limited by surface accuracy (must be < λ/16 rms).
Patch / Microstrip5–8 dBi
HPBW: 60–120°
GPS, mobile phones, aircraft avionics. Low profile, easily integrated; bandwidth typically 2–5%.
Phased Array20–40 dBi (steerable)
HPBW: 1°–30° (electronic)
5G massive MIMO, AESA radar, satellite. Beam steered in µs without moving parts; can form multiple simultaneous beams.
Related Tools
Put these concepts to work

Yagi Designer

Design a Yagi-Uda antenna with calculated gain and beamwidth

Helical Antenna Calculator

Calculate helical antenna gain, beamwidth, and input impedance

Antenna Calculator

Calculate dipole, monopole, and folded dipole antenna dimensions