An antenna includes a feeding element and at least one non-feeding element. A vertical distance between each non-feeding element and the feeding element falls within a specified threshold, each non-feeding element includes a first conductor that is grounded, a regulator circuit, and a control switch disposed on the first conductor and configured to control the regulator circuit, where the regulator circuit is configured to regulate a current path length of the non-feeding element. The non-feeding element forms a reflector when the regulator circuit is enabled, or the non-feeding element forms a director when the regulator circuit is disabled. A design in which the reflector and the director are compatible is used such that a combination of one feeding element, M directors and N reflectors is implemented for the antenna to achieve a high directive gain and interference suppression capability.

A radio frequency (RF) antenna unit is described. The RF antenna unit includes a feed portion, at least first and second selective grounding portions each configured to selectively enable or disable an electrical coupling to a substrate, and at least first and second conductive arms. The first conductive arm provides electrical conduction between the feed portion and the first grounding portion, extending from the first grounding portion towards and beyond the feed portion. The second conductive arm provides electrical conduction between the feed portion and the second grounding portion, extending from the second grounding portion towards and beyond the feed portion. First and second inverted F antenna (IFA) elements are defined by the feed portion, the respective first or second grounding portion and the respective first or second conductive arm. The feed portion is common to both the first and second IFA elements.

An example antenna system includes a plurality of driven elements and at least one dielectric antenna array. The at least one dielectric antenna array include a central hub. Each driven element extends transversely through the central hub. The at least one dielectric antenna array further includes a plurality of dielectric rods extending outwards from the central hub. Each dielectric rod is driven by a respective one of the driven elements. The antenna system further includes a control circuit coupled to the at least one dielectric antenna array to switch the driven elements to drive one or more of the dielectric rods to transmit or receive radio frequency (RF) waves.

A directional antenna apparatus capable of radiating radio signals in various directions may include first, second, third and fourth main director elements forming a square; first, second, third and fourth sub-director elements extending from the center portion of the square to the first, second, third and fourth main director elements, respectively, inside the square; first, second, third and fourth radiators disposed in parallel with the first, second, third and fourth main director elements, respectively, outside the square; and a selection switch configured to selectively connect any one of the first, second, third and fourth radiators to an external device.

A high-power electromagnetic source for HPEM pulses in a desired radiation direction includes at least three antennas fixed in relation to one another for pulse components, wherein at least two groups of antennas with a respective main direction are present, and a control unit for the activation and phase position of the pulse components for the superimposition for the HPEM pulse, wherein the current radiation direction of said pulse is selectable in an angle range around the main direction. A vehicle with an HPEM source has the antennas mounted in a fixed position or a support for the antennas is pivotably mounted on the vehicle. In a method for emitting the HPEM pulse, all antennas are controlled in order to select the radiation direction in the angle range of less than 360.

An antenna system for receiving and transmitting wireless signals includes a first complex antenna including a first reflection element, a first antenna array and a second antenna array; a second complex antenna including a second reflection element, a third antenna array and a fourth antenna array, wherein the first reflection element and the second reflection element are fixed to form an included angle to each other; and a feeding device, coupled to the first complex antenna and the second complex antenna, for alternately outputting radio-frequency signals to the first complex antenna and the second complex antenna, to emit wireless signals via the first complex antenna and the second complex antenna, and switching phases of the radio-frequency signals outputted to the first complex antenna and the second complex antenna, to change characteristics of beam generated by the first complex antenna and the second complex antenna in a vertical plane.

Systems and methods for detecting and reducing signal interference affecting wireless communication with a mobile vehicle includes generating an interference signature based on a correlation multiple signal-quality characteristics of a desired target-signal that is received at an antenna assembly attached to the mobile vehicle, and adjusting the orientation of the antenna assembly based on a change or degradation in the interference signature to thereby improve wireless communication with the vehicle.

A radio frequency (RF) antenna unit is described. The RF antenna unit includes a feed portion, at least first and second selective grounding portions each configured to selectively enable or disable an electrical coupling to a substrate, and at least first and second conductive arms. The first conductive arm provides electrical conduction between the feed portion and the first grounding portion, extending from the first grounding portion towards and beyond the feed portion. The second conductive arm provides electrical conduction between the feed portion and the second grounding portion, extending from the second grounding portion towards and beyond the feed portion. First and second inverted F antenna (IFA) elements are defined by the feed portion, the respective first or second grounding portion and the respective first or second conductive arm. The feed portion is common to both the first and second IFA elements.

An antenna unit, an antenna system and an antenna control method are disclosed. The antenna unit includes a first radiation metal element, a second radiation metal element, and a third radiation metal element. The first radiation metal element includes a signal feed point, a first ground point, and a second ground point. The signal feed point, the first ground point, and the second ground point are disposed approximately in a straight line. The second radiation metal element is disposed away from the first radiation metal element with a gap and includes a third ground point. The third radiation metal element surrounds the first radiation metal element and the second radiation metal element and includes a fourth ground point.

A switchable artificial magnetic conductor (S-AMC) element that includes a conductive layer, a conductive patch located on one side of the conductive layer and electrically isolated from the conductive layer, and an open stub located on an opposite side of the conductive layer and electrically isolated from the conductive layer. A switch element is configured to selectively open and close an electrical connection between the conductive patch and the open stub in response to a control signal. When the electrical connection is closed the conductive patch presents a high impedance, magnetically conductive surface for radio frequency (RF) signals within a defined frequency band, and when the electrical connection is open the conductive patch presents an electrically conductive surface for RF signals within the defined frequency band.