See also: Patch

The technology of the planar antenna (official term in French language) or antennas patch , development of surface, often on printed circuit doubles face, is retained in the category of the antenna S known as punts or hooded panels. One uses the patch as of the Bande L/S.

The planar or plane antennas are used in Wi-Fi, Radioamateurisme and certain professional transmissions. Their announced and theoretical profit (with 2,4 GHz) varies according to the number of elements. More the cells are numerous plus the antenna is directing and its surface (square or rectangular) is important.

• 2 cells: 12 dBi
• 4 cells: 15 dBi (= parabola of approximately 30 cm)
• 8 cells: 18 dBi
• 16 cells: 21 dBi (= parabola of approximately 60/65 cm)

These plane antennas are available either for the horizontal polarization linear or vertical or for left or right circular polarization. In Wifi linear polarization is preferred, circular polarization is rather employed by the Radioamateur S.

The Camera without wire (or some) analogical, example of application, Webcam off-set, is equipped with an antenna punt using to it (1) patch having a hot dimension of 31,5 X 31,5 mm with an axial point located at 11 mm of the edge. If the square is chopped on 2 opposed sides, polarization is announced is circular, one then loses 3 dB if one it Marie with the linear one. The dimension of the back face (connected to the mass of coaxial) is not critical, often 40 to 50 mm on side. The aperture (with - 3 dB) of a paving stone of patch is at least of 120° with 2,4 GHz.

The illustration details the design of an antenna 2,4 GHz ( Stella Doradus ) here seen for linear polarization H, with 16 elements (patch of 63 X 50 mm) with the lines of coupling. The circuit measuring 38 X 39 cm brings a profit of 21dBi (or 19 dBd) what makes this antenna the air one with the best most powerful output (coefficient K) and compared to its size (obstruction L 45 X L 45 X P 4,5 cm, P max 13 cm with fixing for mast). Moreover, the report/ratio before/back is one of best, 38 dB, which allows a protection raised against the disturbances coming from the back (180°) of the antenna. To pass from polarization H to V, the panel is turned of 90°.

The antenna patch is air the most discrete in its category of profit, because the least bulky, immediately followed Antenne quad, then of the Antenna horn and Antenne horn-funnel.

External bonds

• Information on the antennas patch
• Brest-wireless