Abstract: Systems and methods for operating an antenna assembly. The methods comprise: receiving, at the first polarized antenna, a first signal comprising a desired signal emitted from a first signal source located at a first altitude higher than a second altitude of the antenna assembly and an interfering signal emitted from a second signal source located at a third altitude lower than the second altitude; receiving the interfering signal at the second polarized antenna (where the first and second polarized antennas have opposite circular polarizations); generating a second signal by shifting a phase of the interfering signal which was received at the second polarized antenna by an amount to cause the second signal to be out-of-phase with the first signal; and providing an antenna pattern with a null at or below a horizon by destructively combining the second signal with the first signal.

Abstract: Systems and methods for operating a direction finder device. The methods comprise: mechanically steering an antenna system of a first platform at a first time such that a null of a first antenna pattern points in a first null direction towards an interference source; obtaining a first location of the first platform at the first time; mechanically steering the antenna system of the first platform at a second time such that the null of the first antenna pattern points in a second null direction towards the interference source (wherein the second direction is different than the first direction); obtaining a second location of the first platform at the second time, wherein the second location is different than the first location; and using the first location, the second location, the first null direction and the second null direction to determine a first estimated location of the interference source.

Abstract: Systems and methods for autonomously operating an antenna assembly. The methods comprise: obtaining, by a processor of the antenna assembly, first information comprising at least one of a value for a variable altitude of the antenna assembly, a value for a variable height of the antenna assembly above ground, a value for a variable height of the antenna assembly above sea level, a value for a variable distance of the antenna assembly from a reference object, and a first value for a variable signal frequency of a communication device; using, by the processor, the information to obtain a desired length of an antenna of the antenna assembly; and controlling, by the processor, an actuator to adjust a length of the antenna until the length reaches the desired length.

Abstract: Systems and methods for autonomously operating an antenna assembly. The methods comprise: obtaining, by a processor of the antenna assembly, first information comprising at least one of a value for a variable altitude of the antenna assembly, a value for a variable height of the antenna assembly above ground, a value for a variable height of the antenna assembly above sea level, a value for a variable distance of the antenna assembly from a reference object, and a first value for a variable signal frequency of a communication device; using, by the processor, the information to obtain a desired length of an antenna of the antenna assembly; and controlling, by the processor, an actuator to adjust a length of the antenna until the length reaches the desired length.

Abstract: An antenna system, comprising: an omni-directional antenna element; and a directional adapter having an electromagnetic reflector. The directional adapter detachably coupled to the omni-directional antenna element. The electromagnetic reflector being offset from the omni-directional antenna element. The directional adapter may be configured to be coupled to the antenna to convert a radiation pattern from an omni-directional antenna radiation pattern to a directional antenna radiation pattern, and configured to be decoupled from the antenna to convert the radiation pattern back into the omni-directional antenna radiation pattern.

Abstract: A vehicle may comprise a frame, a propulsion arrangement configured to orient the frame, and an antenna carried by the frame. The antenna may include a housing, a base carried by the housing, a pair of spaced apart antenna elements carried by the base, and a phase sifter coupled to the pair of antenna elements to define an antenna pattern having a pair of opposing nulls. An RF receiver is coupled to the antenna. A controller may control the propulsion arrangement to orient the frame to steer the antenna pattern based upon the RF receiver.

Abstract: A radio frequency (RF) device for a vehicle may include an antenna, an RF receiver and a controller. The antenna may include a housing, a rotatable base carried by the housing, an actuator to selectively rotate the base, a pair of spaced apart antenna elements carried by the rotatable base, and a phase sifter coupled to the pair of antenna elements to define an antenna pattern having a pair of opposing nulls. The RF receiver is coupled to the antenna, and the controller may drive the actuator to steer the antenna pattern based upon the RF receiver.

Abstract: Systems and methods for operating an antenna assembly. The methods comprise: receiving, at the first polarized antenna, a first signal comprising a desired signal emitted from a first signal source located at a first altitude higher than a second altitude of the antenna assembly and an interfering signal emitted from a second signal source located at a third altitude lower than the second altitude; receiving the interfering signal at the second polarized antenna (where the first and second polarized antennas have opposite circular polarizations); generating a second signal by shifting a phase of the interfering signal which was received at the second polarized antenna by an amount to cause the second signal to be out-of-phase with the first signal; and providing an antenna pattern with a null at or below a horizon by destructively combining the second signal with the first signal.

Abstract: Systems and methods for operating an antenna assembly. The methods comprise: receiving, at the first circularly polarized antenna, a first signal comprising a desired signal emitted from a first signal source located at a first altitude higher than a second altitude of the antenna assembly and an interfering signal emitted from a second signal source located at a third altitude lower than the second altitude; receiving the interfering signal at the second circularly polarized antenna (where the first and second circularly polarized antennas are disposed on opposite sides of an antenna reflector and having opposite circular polarizations); generating a second signal by shifting a phase of the interfering signal which was received at the second circularly polarized antenna by an amount to cause the second signal to be out-of-phase with the first signal; and providing an antenna pattern with a null at or below a horizon by destructively combining the second signal with the first signal.

Abstract: Systems and methods for operating an antenna assembly. The methods comprise: receiving, at the first circularly polarized antenna, a first signal comprising a desired signal emitted from a first signal source located at a first altitude higher than a second altitude of the antenna assembly and an interfering signal emitted from a second signal source located at a third altitude lower than the second altitude; receiving the interfering signal at the second circularly polarized antenna (where the first and second circularly polarized antennas are disposed on opposite sides of an antenna reflector and having opposite circular polarizations); generating a second signal by shifting a phase of the interfering signal which was received at the second circularly polarized antenna by an amount to cause the second signal to be out-of-phase with the first signal; and providing an antenna pattern with a null at or below a horizon by destructively combining the second signal with the first signal.

Abstract: Systems and methods for autonomously operating an antenna assembly. The methods comprise: obtaining, by a processor of the antenna assembly, first information comprising at least one of a value for a variable altitude of the antenna assembly, a value for a variable height of the antenna assembly above ground, a value for a variable height of the antenna assembly above sea level, a value for a variable distance of the antenna assembly from a reference object, and a first value for a variable signal frequency of a communication device; using, by the processor, the information to obtain a desired length of an antenna of the antenna assembly; and controlling, by the processor, an actuator to adjust a length of the antenna until the length reaches the desired length.