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A conformal antenna [14] is a phased array in which the individual antennas, instead of being arranged in a flat plane, are mounted on a curved surface. The phase shifters compensate for the different path lengths of the waves due to the antenna elements' varying position on the surface, allowing the array to radiate a plane wave.
Most antennas boresight axis is fixed by their shape and cannot be changed. However phased array antennas can electronically steer the beam, changing the angle of the boresight by shifting the relative phase of the radio waves emitted by different antenna elements, and even radiate beams in multiple directions (multiple boresights). [1]
An antenna array (or array antenna) is a set of multiple connected antennas which work together as a single antenna, to transmit or receive radio waves. [ 1 ] : p.149 [ 2 ] The individual antennas (called elements ) are usually connected to a single receiver or transmitter by feedlines that feed the power to the elements in a specific phase ...
Apparent phase center is used to describe the phase center in a limited section of the radiation pattern. If it is used in the context of an antenna array, one has to define a reference point from which the basevectors of the single elements are referred to. [1] The phase center may vary, depended on the beamforming algorithm.
Phase-comparison monopulse is a technique used in radio frequency (RF) applications such as radar and direction finding to accurately estimate the direction of arrival of a signal from the phase difference of the signal measured on two (or more) separated antennas [1] or more typically from displaced phase centers of an array antenna. Phase ...
It was a large two-dimensional phased array with beam steering controlled by computers instead of requiring mechanical motion of the antenna. The first module, a linear array, was completed in 1960. It formed the basis of the AN/FPS-85. [1] Starting in the 1960s, new solid-state devices capable of delaying the transmitter signal in a controlled ...
A phase correcting reflective array consists of an array of phase shifting elements illuminated by a feed placed at the focal point. The word "reflective" refers to the fact that each phase shifting element reflects back the energy in the incident wave with an appropriate phase shift. The phase shifting elements can be passive or active.
Frequency-dependant phase shifting of the elements of the array can be used to compensate for the squint, [4] which leads to the concept of a squintless antenna or feed. [5] Design In some cases the antenna may be designed to create a squint. For example, an antenna which is used to communicate with a satellite but must remain in a vertical ...