Antenna system for handheld satellite communication devices
An antenna systems for a handheld wireless device comprises an antenna disposed proximate an oblong ground structure (e.g., oblong PCB). The antenna is suitably adapted to radiated circularly polarized waves by supporting quadrature phased first and second resonances which are associated with electrical fields oriented at right angles to each other and at an oblique angle relative to a longitudinal axis of the oblong ground structure.
1. An antenna system comprising:
an oblong planar circuit board having a top side, a bottom side and a longitudinal axis;
a dielectric support having a first side and a second side, the dielectric support positioned on the top side of the oblong planar circuit board, with the first side of the dielectric support in contact with the top side of the oblong printed circuit board;
a rectangular antenna patch positioned on the second side of the dielectric support wherein the rectangular antenna patch has a geometrical center and supports two orthogonal modes, and wherein the rectangular antenna patch is mounted off center with respect to the dielectric support, and wherein the rectangular antenna patch is oriented obliquely with respect to the longitudinal axis at an angle between 40° and 50° with respect to the longitudinal axis;
a feed pin connected to a location on the rectangular antenna patch offset from the geometrical center of the rectangular antenna patch and coupled to a trace on the bottom side of the oblong planar circuit board; and
a main board that is adjacent to the oblong planar circuit board, is larger than the oblong planar circuit board and is conductively coupled to the oblong planar circuit board.
2. The antenna system according to claim 1 wherein the rectangular antenna patch comprises a square shaped patch and the feed pin connected to the square shaped patch at a location displaced from a center of the square shaped patch.
3. The antenna system according to claim 2 wherein the rectangular antenna patch is oriented at 45° with respect to the longitudinal axis.