Array antennas of different geometry/shapes are used in all wireless communication systems. An array antenna is typically constructed with a set of basic antenna elements arranged in an array. Such an array can often be linear—elements arranged in a line, can be planar, circular, cylindrical and spherical, etc. Depending on applications, each has their role in wireless communication applications.
Array beam pattern synthesis is to combine all elements in an array with complex weights so as to create beam patterns of the desired direction and shape. Effective synthesis and antenna construction has been studied for decades. There are many difficult factors that affect the effectiveness of an array antenna. For instance, mutual coupling among basic elements, element spacing variations in an array (which requires oftentimes high precision mechanical processes), element gain and basic pattern variations, array re-calibration (upon element failure in an array), and high quality beams.
Li has described a method and apparatus for constructing linear (including flat panel) wireless array antenna systems (U.S. Pat. No. 6,911,954 B2). The advantages include a beam synthesis method that incorporates all aforementioned factors into a one-step systematic approach. Mutual coupling, element spacing and gain variations, high quality beam can all be accounted for simultaneously. Array re-calibration (upon element failure detection) is also exceedingly easy in Li's method so that the array can still function in its maximum capacity as allowed by the physics exhibiting in the (remaining) array.
While Li's method is seen to bring in significant improvements to the construction of many useful array antenna systems, array antenna systems of other shapes, for instance, constructed over a cylindrical surface, a spherical surface, or any other three dimensional (3D) geometry (or General Wireless Array Antenna Systems) are still to be constructed in similar ways, taking advantages just as those in Li's method.
The construction of general wireless array antenna systems is considerably more complicated. Precise 3D beam synthesis has not been seen. Existing methods of construction of general array antennas are very limited. None has been able to incorporate aforementioned factors into the design simultaneously. Beam quality is also very restricted.
Thus, a better method for general array antenna constructions that provides better beam quality and directivity is needed, one that resolves the many factors in array beam synthesis, provides a precise 3D array synthesis, enables the array re-calibration and render existing construction method obsolete.
USPTO Backgrounds
USPTO Backgrounds