The patch resonates mainly according to its dimensions. Radiation comes primarily from fringing fields at the patch edges.
Antennas · F1SYH
Patch antenna
A patch antenna is a flat metallic element above a ground plane and separated by a dielectric substrate.
UHF
SHF
Plane
Operating principle
Main characteristics
Typical gain
Environ 5 à 9 dBi
Impedance
Adaptable à 50 Ω
Polarization
Linéaire ou circulaire
Difficulty
Très avancée
Dimensions and design
Width and length depend on frequency, substrate permittivity and thickness. Fringing effects must be included.
Construction and tuning
Step 1
Choose a substrate with known properties.
Step 2
Calculate patch width and length.
Step 3
Provide a sufficient ground plane.
Step 4
Determine the feed point or microstrip line.
Step 5
Manufacture accurately.
Step 6
Measure with a VNA and adjust carefully.
Advantages
- Very low profile.
- Printed-circuit integration.
- Circular polarization possible.
- Suitable for arrays.
Limitations
- Often narrow bandwidth.
- Dielectric losses.
- Critical precision at high frequencies.
- Sensitive to enclosure and radome.
History and origin
Microstrip antennas developed with printed circuits, aerospace, satellites and compact radio systems.
Safety
Observe RF exposure limits near high-power or high-gain patch arrays.