The two vertical elements radiate in phase and create a low-angle bidirectional pattern suitable for DX.
Antennas · F1SYH
Half-Square
The Half-Square consists of two quarter-wave vertical elements joined by a half-wave horizontal section.
HF
DX
Polarisation verticale
Operating principle
Main characteristics
Typical gain
Environ 3 à 4 dBi selon sol
Impedance
Variable selon alimentation
Polarization
Verticale
Difficulty
Intermédiaire
Dimensions and design
Vertical sides are near ¼ wavelength and the horizontal section near ½ wavelength.
Construction and tuning
Step 1
Calculate both vertical sections.
Step 2
Calculate the horizontal connecting wire.
Step 3
Install two separated supports.
Step 4
Choose corner or end feeding.
Step 5
Keep vertical sections clear.
Step 6
Tune resonance in the final position.
Advantages
- Low take-off angle.
- Vertical polarization without a conventional radial system.
- Wire construction.
- Bidirectional gain.
Limitations
- Requires two supports.
- Bidirectional pattern.
- Feed may be complex.
- Strong ground influence.
History and origin
The Half-Square belongs to the family of phased wire vertical arrays developed for long-distance communication.
Safety
Lower ends must remain out of reach even though they are close to ground.