The two Yagis may be fed separately, switched between linear polarizations or fed in quadrature for circular polarization.
Antennas · F1SYH
Cross-Yagi
A Cross-Yagi combines two identical Yagi antennas mounted at right angles on the same boom.
VHF
UHF
Satellites
Operating principle
Main characteristics
Typical gain
Élevé selon nombre d’éléments
Impedance
Deux systèmes adaptés et phasés
Polarization
Circulaire ou commutable
Difficulty
Très avancée
Dimensions and design
Each element plane is a complete Yagi. Interaction between planes requires simulation or a validated design.
Construction and tuning
Step 1
Build two strictly identical Yagis.
Step 2
Mount them at 90 degrees.
Step 3
Respect the designed longitudinal offset.
Step 4
Match each polarization separately.
Step 5
Build the phasing network.
Step 6
Verify circular-polarization sense.
Advantages
- High gain.
- Circular polarization.
- Switchable polarization.
- Excellent for weak signals.
Limitations
- Complex construction.
- Two feeds and matching systems.
- Azimuth-elevation rotor often required.
- Element interaction.
History and origin
Crossed arrays developed with space communication and the need for directive circular polarization.
Safety
Boom, rotors and cables must withstand weight, torque and wind loading.