Definition
A dipole is the most fundamental practical antenna: a straight conductor, classically a half-wavelength long, fed at its centre so the two arms radiate. It serves as the reference against which other antennas are often described, and it forms the driven element inside more complex designs. A half-wave dipole presents a convenient feed impedance and a well-understood radiation pattern, which is why it appears everywhere from broadcast to mesh radio.
Radiation pattern
A vertical half-wave dipole radiates in an omnidirectional, doughnut-shaped pattern: roughly equal coverage in every horizontal direction with nulls straight off the ends of the conductor. This makes it the natural choice for a hub node that must hear and be heard by peers scattered in all directions, unlike a directional design that favours a single axis. Its modest gain, near 2.15 dBi, is the baseline that gives rise to the dBi unit itself.
Why it matters for mesh nodes
For sovereign off-grid radio, most stock LoRa and Meshtastic nodes ship with a vertical dipole or its compact relative, the monopole, precisely because omnidirectional coverage suits an ad-hoc mesh where neighbours can lie in any bearing. Correct length, tuned to the operating wavelength, and vertical mounting matter more for real-world range than raw power.
The dipole is the building block of larger antennas. See Yagi Antenna which uses a dipole as its driven element, Wavelength for sizing it, and dBm for the power units involved.
In Simple Terms
A dipole is the most fundamental practical antenna: a straight conductor, classically a half-wavelength long, fed at its centre so the two arms radiate. It…