A low-profile antenna has increased broad-banding capacities as well as a lower
radiation angle for enhanced cellular or mobile telephone
wireless transmissions. Enhancing a basic PIFA antenna, a top
metal radiator is notched so as to provide additional corners and greater perimeter length thereby enhancing the bandwidth capabilities of the antenna. Both ground and tuning tabs serve to enhance operational characteristics and a
dielectric cover incorporating prismatic qualities serves to lower the
radiation angle of transmission from approximately forty degrees (40 DEG ) to twenty degrees (20 DEG ). The prisms provide an operating
radiation angle in the range of approximately seventy degrees (70 DEG ) to twenty degrees (20 DEG ). In one embodiment, a sheet of
plastic foam slightly thicker than the depth of an associated connector is secured to the underside of the bottom plate to act as a friction seal when the antenna is screwed onto a
mating connector, allowing for slight variations in the curvature of the mounting surface. By making the bottom conductive plate only slightly larger than the top radiator, the antenna's resonant frequency becomes independent of
ground plane mounting and may not require such a
ground plane. Under such circumstances, some adjustment of the tuning parameters may be required in order to provide optimum response.