← Back to catalog

Folded Dipole

Wire Antennas HF VHF 🔧 Buildable at home

A dipole made from a closed loop of two parallel conductors for higher impedance and bandwidth.

Band
HF to UHF
Gain
~2.15 dBi
Polarization
Linear (element orientation)

Photos

Real-world photo of a Folded Dipole in use
Real-world example. Source: Wikimedia Commons (CC BY-SA 4.0; Secretlondon).

Radiation / wave patterns

New to these diagrams? How to read a radiation pattern →

Radiation pattern of the Folded Dipole
Mounted horizontally. In the plane containing the wire the pattern is a figure-eight: strongest broadside (perpendicular to the wire), nulls off the ends.

How & why it works

A folded dipole joins two closely spaced half-wave conductors at the ends to form a thin loop, fed at the middle of one side. The current splits between the two conductors, which raises the feedpoint impedance to about 300 ohms—a four-fold step-up over a plain dipole—making it a natural match for 300-ohm twin-lead and the driven element of many Yagis. The two-wire structure also widens the usable bandwidth and adds mechanical robustness.

Real-world uses

FM/TV receive antennas, Yagi driven elements, and 300-ohm twin-lead installations.

Make one at home

A practical starting point — always trim and check SWR for your exact frequency.

See the finished antenna pictured above ↑.

A folded dipole is a dipole made from a loop of wire — more bandwidth and a handy 300-ohm feed.

You’ll need

  • 300-ohm TV twin-lead (the simplest route) or two parallel wires with spacers
  • A 4:1 balun (300 Ω → 75 Ω) or 6:1 (300 Ω → 50 Ω) to feed with coax

Build

  1. Cut a length of twin-lead = 143 ÷ f(MHz) metres.
  2. At the two far ends, twist and solder the two conductors together (closing the loop).
  3. At the centre of one conductor, cut it and connect the balun there; the other conductor stays continuous.

Tune

Trim both ends equally for lowest SWR. The folded design is broad, so it’s forgiving.

Safety

  • Keep antennas well clear of power lines — never put one where it could fall onto or contact mains wiring.
  • Don’t transmit while anyone is close to the antenna; mind RF-exposure limits and your local licensing rules.
  • Ground masts and use coax surge protection where appropriate.
  • Cutting/soldering: eye protection and a ventilated space.