When communicating between electronic devices without wires, antennas are used to transmit information between the electronic devices. On the both ends, the antennas are designed to improve the signal strength. Optimizing antenna element properties such as signal phase, signal amplification, and element position minimize the loss of energy when transmitting and thus reduces the amount of power required to transmit the signal and improves the quality of the signal sent. Optimizing such properties for a receiving antenna yields similar results.
Most antennas are designed in ideal laboratory conditions before they are connected to real devices. However, real operating conditions can deviate far from ideal conditions due to the environmental noise, system noise, severe weather conditions, interference with other signals, and terrain. In these unpredictable situations, the antenna does not fulfill its design goal and exhibits significantly degraded performance. One solution to these problems is the use of variable antennas. Conventional styles of variable antennas include directional antennas on rotating mounts and “rabbit ear” television antennas. The position of the variable antenna elements can be changed to adapt to changing signal conditions by either manual adjustment or a motor. Variable antennas generally require many adjustments to find a suitable antenna position to attain acceptable signal reception. Finding the best position of directional antennas on rotating mounts is easy because one would need to rotate the antenna only once around the axis and then pick the best position. However, “rabbit ear” style antennas which have two telescoping elements that can rotate through two different axes are much more complex because such antennas cannot test all possible lengths and angular positions of two elements in a reasonable amount of time. The final antenna positions are unlikely to be optimal because of the vast number of possible positions that such an antenna with two elements can take. Antennas could certainly be built with more elements than “rabbit car” style antennas, such as antennas created by connecting multiple telescoping and rotating elements. In this case, it would be impossible to obtain optimized positions of all elements because of the extraordinary number of possible combinations of element positions.
Although “rabbit ear” style antennas can be used to receive television signals, better reception can be achieved with outdoor antennas mounted on the outside or roof of a household. These antennas are usually large dipole, multiple elements Uda-Yagi, or multiple element bay antennas. All of these antennas have antenna elements that are fixed to a singular frame. Therefore, the angular positions and length of the antenna elements cannot be adjusted. The most movement any of these antennas can have is rotating around their mount point on a roof. While these antennas work well in most situations, their capabilities are limited, to some degree, in that both broadband signal reception and clear signal reception on a specific frequency are required and these two factors are opposing design factors.
Most existing adaptive or smart antennas use an array of fixed elements whose combined signal is controlled by an algorithm that determines proper values for the phase and gain of signals received at each element in the array. These antennas work in cellular towers for cell phone communications. Such antennas only have the ability to electrically modify the signal received by fixed elements in the array. These algorithms are designed to be used in specific antenna systems and the addition of variable length and variable positioning to these antennas would render the control algorithms for these antennas unusable.
What is needed is a system and method for efficiently optimizing positioning of receiving elements of a variable antenna. The needed system and method would be able to dynamically adapt in real time to the continually changing signal environments due to the environmental noise, system noise, severe weather conditions, interference with other signals, clutters, and terrain.