An omni-directional horizontally polarized antenna system is provided that can include an omni-directional vertically polarized antenna and a plurality of linear polarization filters concentrically surrounding the omni-directional vertically polarized antenna. The omni-directional vertically polarized antenna can generate a vertically polarized field, and the plurality of linear polarization filters can progressively rotate the vertically polarized field 90° to form a horizontally polarized field outside of the plurality of linear polarization filters.

A communication system using vector and scalar potential is disclosed. The system uses field-free potentials signaling for many applications where the absence of shielding effects in sea water, plasma or other dense media due to the fact that the absence of (E,B) fields eliminates the possibility of induced charge and current response in the media being transited.

A method for non-invasively imaging plasma parameters has been invented. Crossed dipole pairs are used to differentiate changes in the measured complex self- and mutual impedances due to plasma density and magnetic field. Measurements of the complex self-impedance and mutual impedance between pairs of antennas over a wide range of frequencies provide spatial information to create an image of the plasma density and magnetic field. The spectral information is acquired simultaneously using a Gaussian monopulse as the driver signal.

A filter which stops the propagation of an electromagnetic wave of a predetermined frequency band in a signal line or a power supply line is provided. This filter is a conductor connected to the signal line or the power supply line. This conductor is configured to include a linear portion. The first portion of the linear portion with an end portion connected to the signal line or the power supply line has the first width, and the second portion different from the first portion of the linear portion has the second width different from the first width.

Dipole antenna arrays are disclosed. An example dipole antenna array includes a ground plane having a first serrated edge, and a first dipole antenna, at least a portion of the first dipole antenna disposed parallel to the first serrated edge.

Dipole antenna arrays are disclosed. An example dipole antenna array includes a ground plane having a first serrated edge, and a first dipole antenna, at least a portion of the first dipole antenna disposed parallel to the first serrated edge.

A dipole antenna is disclosed herein. The dipole antenna may include, but is not limited to, a first transmission line configured to receive a radio frequency signal from a first feed, a first balun galvanically coupled to the first transmission line, a first conductive strip galvanically coupled to the first transmission line and the first balun, a second conductive strip galvanically coupled to the first transmission line and the first balun, a first dipole arm, and a second dipole arm, wherein the first balun and the first transmission line are only capacitively coupled to the first and second dipole arms via the first and second conductive strips.

A dipole antenna is disclosed herein. The dipole antenna may include, but is not limited to, a first transmission line configured to receive a radio frequency signal from a first feed, a first balun galvanically coupled to the first transmission line, a first conductive strip galvanically coupled to the first transmission line and the first balun, a second conductive strip galvanically coupled to the first transmission line and the first balun, a first dipole arm, and a second dipole arm, wherein the first balun and the first transmission line are only capacitively coupled to the first and second dipole arms via the first and second conductive strips.

A radiofrequency transmission/reception device includes a first and a second conductive wire element, a first far-field transmission/reception chip and a second near-field transmission/reception chip. The first and the second wire element combine with the characteristic impedance of the second transmission/reception chip in order to form a coupling device associated with the first transmission/reception chip at the operating frequency of the first chip. The first and the second wire element combine with the characteristic impedance of the first transmission/reception chip in order to form a coupling device associated with the second transmission/reception chip at the operating frequency of the second chip.

A direction-finding antenna system is described. The direction-finding antenna system comprises a plurality of tapered dipole antenna elements arranged in circular array around a central axis. Each tapered dipole antenna element comprises a pair of rectangular elongated antenna elements mounted radially from said central axis and configured to be curved such that a distance between said pair of rectangular elongated antenna elements is larger at periphery of the system with respect to center thereof.