Abstract: An antenna having an active radome for beam steering and/or nulling in accordance with several embodiments can include at least one omni-directional radiating element, a radome surrounding the radiating element, and a network of conductive segments that can be placed between the radome and radiating element. A plurality of switches can interconnect the conductive segments to form the network. The switches can be FET, MOSFET and optical switches, and can be selectively closed when the element radiates or receives RF energy to selectively establish connectivity between the conductive segments, which can achieve a selective Yagi-like effect for the antenna. The conductive segments network can have any geometric profile when viewed in top plan, such as octagonal, square and the like, provided the segments surround the radiating element. A processor can be used to provide a control algorithm, which can contain non-transitory written directions that selectively activate and deactivate the switches.

Abstract: A method for transmitting information by radio over a wide bandwidth comprises the steps of: inputting a data signal into a time varying filter modulator; spreading the data signal in time and in frequency to produce a wideband signal; modulating the wideband signal onto an RF carrier to provide an RF output signal; and transmitting the RF output signal. The step of spreading includes performing a series of linear transformations to the data signal.