ground plane than the IFA. The patch can be made multi-band, although not quite as easily as the IFA. A microstrip patch antenna is most often a 1/2 wavelength structure although it can also be made as a 1/4 wave element. The patch can be very low-profile, only a few mm thick.
Most often, patch antennas are printed on the top surface a 2-layer PCB, although sheet metal patches over a ground plane with an air-dielectric are also in wide use.
Patch antennas are considered directional antennas with a primary lobe of radiation over an approximately 70 x 70 degree sector (in the direction away from the ground plane). The photo below shows a typical printed patch antenna.
Figure 6 . Printed Patch Antenna
Because of the directional nature and surface-area requirement, patch antennas are rarely used on hand-held mobile devices. However, the patch antenna may be an excellent choice for a fixed-mount device on the side of building where the
Antenna Fundamentals – Technical Brief