Parabolic reflector antennas advantageously utilize feed boom mounted dielectric lens structures to support enhanced radiation pattern control. A parabolic reflector antenna includes a dish reflector, a feed boom waveguide having a proximal end coupled to the dish reflector, a sub-reflector assembly and a dielectric lens. The sub-reflector assembly may include a dielectric block coupled to a distal end of the feed boom waveguide and a sub-reflector adjacent a distal end of the dielectric block. The dielectric lens may be provided on the feed boom waveguide at a location intermediate the proximal and distal ends of the feed boom waveguide.

An antenna system including a ground plane, an antenna radiator separated from and overlapping the ground plane and at least one first conductive element extending the antenna radiator towards the ground plane. The antenna system also includes at least one feed element configured to provide a radio-frequency feed for the antenna radiator. The feed element is spatially separated from the first conductive element and the antenna radiator.

Microwave antenna systems include a parabolic reflector antenna having a feed bore and a feed assembly. The feed assembly includes a coaxial waveguide structure that extends through the feed bore, a sub-reflector, and a first dielectric block that is positioned between the coaxial waveguide structure and the sub-reflector. The coaxial waveguide structure includes a central waveguide and an outer waveguide that circumferentially surrounds the central waveguide. One of the central waveguide and the outer waveguide extends further from the feed bore towards the sub-reflector than the other of the central waveguide and the outer waveguide.

A system includes a first antenna and a second antenna. The first antenna includes an antenna section. The antenna section includes a first antenna segment, a second antenna segment adjacent to the first antenna segment, and a notch circuit disposed within a notch between the first antenna segment and the second antenna segment. The notch circuit prevents a first frequency of a signal from passing from the first antenna segment to the second antenna segment while allowing a second frequency from the signal to pass from the first antenna segment to the second antenna segment. The second antenna is disposed proximate to the first antenna. The first antenna occupies a second near field region of the second antenna and the second antenna occupies a first near field region of the first antenna.

The invention discloses a LTCC wide stopband filtering balun based on discriminating coupling. The filtering balun includes a dielectric, and a first resonator, a second resonator, a first feeding line, a second feeding line, a third feeding line and a metal ground which are arranged inside the dielectric. The two resonators are both half-wavelength resonators distributed on different layers, and the layers are connected through metal through holes. the first feeding line is coupled with a specific area of the first resonator for performing feeding to suppress a second harmonic, and the second feeding line and the third feeding line are coupled with a specific area of the second resonator for performing feeding to suppress a third harmonic, thus realizing a wide stopband filtering performance. The second feeding line and the third feeding line are symmetrically arranged about a center of the second resonator, thus realizing a same-amplitude reverse-phase balun output characteristic. The LTCC wide stopband filtering balun based on discriminating coupling according to the invention can suppress the second harmonic and the third harmonic, and a LTCC multi-layer circuit technology used reduces a size of a filtering balun.

The invention discloses a LTCC wide stopband filtering balun based on discriminating coupling. The filtering balun includes a dielectric, and a first resonator, a second resonator, a first feeding line, a second feeding line, a third feeding line and a metal ground which are arranged inside the dielectric. The two resonators are both half-wavelength resonators distributed on different layers, and the layers are connected through metal through holes. the first feeding line is coupled with a specific area of the first resonator for performing feeding to suppress a second harmonic, and the second feeding line and the third feeding line are coupled with a specific area of the second resonator for performing feeding to suppress a third harmonic, thus realizing a wide stopband filtering performance. The second feeding line and the third feeding line are symmetrically arranged about a center of the second resonator, thus realizing a same-amplitude reverse-phase balun output characteristic. The LTCC wide stopband filtering balun based on discriminating coupling according to the invention can suppress the second harmonic and the third harmonic, and a LTCC multi-layer circuit technology used reduces a size of a filtering balun.

An apparatus, for example a multi-band radio frequency antenna system, comprising: a primary reflector, for example a parabolic reflector; and a near-field feed arrangement comprising: a multi-band waveguide feed comprising a first waveguide feed for a first frequency band and a second waveguide feed for a second frequency band separate to the first frequency band, wherein the first waveguide feed and the second waveguide feed are co-axial and have, respectively, a first aperture and a second aperture; and a splashplate located within the near-field of the first waveguide feed, located within the near field of the second waveguide feed and configured as a feed for the primary reflector.

An apparatus, for example a multi-band radio frequency antenna system, comprising: a primary reflector, for example a parabolic reflector; and a near-field feed arrangement comprising: a multi-band waveguide feed comprising a first waveguide feed for a first frequency band and a second waveguide feed for a second frequency band separate to the first frequency band, wherein the first waveguide feed and the second waveguide feed are co-axial and have, respectively, a first aperture and a second aperture; and a splashplate located within the near-field of the first waveguide feed, located within the near field of the second waveguide feed and configured as a feed for the primary reflector.

A communications system is described which comprises a transmission unit including a transmission circuit 12 operable to output a transmission signal to a ground antenna 22 driven, in use, into a ground formation, and an impedance adjusting unit 20 electrically connected between the transmission circuit 12 and the antenna 22 and operable to adjust the transmission output impedance. A ground antenna 22 is also described comprising a single rod or stake including a first active section 30, a second active section 32 spaced apart from the first section 30 and collinear or coaxial therewith, and an insulating section 34 located between the first and second sections 30, 32, holding the first and second sections 30, 32 in a spaced, collinear or coaxial relationship.

A communications system is described which comprises a transmission unit including a transmission circuit 12 operable to output a transmission signal to a ground antenna 22 driven, in use, into a ground formation, and an impedance adjusting unit 20 electrically connected between the transmission circuit 12 and the antenna 22 and operable to adjust the transmission output impedance. A ground antenna 22 is also described comprising a single rod or stake including a first active section 30, a second active section 32 spaced apart from the first section 30 and collinear or coaxial therewith, and an insulating section 34 located between the first and second sections 30, 32, holding the first and second sections 30, 32 in a spaced, collinear or coaxial relationship.