Abstract: A system and method are for reducing the probability of detection of a Line of Sight type communication and sensor mast. The mast has an upper portion extending upwardly relatively the ground, and a lower portion closer to the ground than the upper portion. The mast at the upper portion is equipped with at least a communication or sensor element. The mast is equipped with an actuator that, based on calculated instructions, is designed to alter the elevation above ground of the mast upper portion so as to achieve an acceptable signal quality with the upper portion of the mast at the lowest possible elevation.

Abstract: A three band whip antenna has a base where the whip antenna along its whole length or part of its length, has a lowest frequency band antenna element and an intermediate frequency band antenna element, wherein a highest frequency band antenna is included in the whip antenna at a position closer to base than the intermediate frequency band antenna element.

Abstract: A transfer unit for transferring a radio frequency signal between a classical antenna tuner and an antenna where the transfer unit comprises a switch for alternatively selecting a first direct route for the radio frequency signal between the tuner and the antenna or a second route via a reactive element; said reactive element comprising a variable serial capacitance and a shunt inductance connected to system earth; and where a control unit controls the switch and is adapted to select the first route when the frequency is above a predetermined value and otherwise select the second route. The variable serial capacitance comprises a set of capacitors organized as a set of binary weighted parallel capacitance values, and the transfer unit further comprises switches to engage or disengage each capacitor from the reactive element to increase or decrease the resulting capacitance as the radio frequency is decreased or increased.

Abstract: A method and device are for calibrating an antenna. At least one switch is spanning sections of a radiating antenna element. A controller is designed to selectively close the switch to be conductive, thus effectively short-circuiting the actual section of the antenna element. The method includes: installing the antenna for field use at least for transmission or reception of signals; then measuring the reflected power from the antenna at least for a number of frequencies or frequency ranges at more than one setting of the switch; and storing the settings that gives a desirable result of reflected power at an actual frequency or frequency range.

Abstract: A transfer unit for transferring a radio frequency signal between a classical antenna tuner and an antenna where the transfer unit comprises a switch for alternatively selecting a first direct route for the radio frequency signal between the tuner and the antenna or a second route via a reactive element; said reactive element comprising a variable serial capacitance and a shunt inductance connected to system earth; and where a control unit controls the switch and is adapted to select the first route when the frequency is above a predetermined value and otherwise select the second route. The variable serial capacitance comprises a set of capacitors organized as a set of binary weighted parallel capacitance values, and the transfer unit further comprises switches to engage or disengage each capacitor from the reactive element to increase or decrease the resulting capacitance as the radio frequency is decreased or increased.

Abstract: A device of a rod antenna comprising a supply transformer and first and second beam elements, wherein both beam elements are provided with a ferrite material.