Base station antennas include an externally accessible active antenna module releasably coupled to a rear of the housing. The base station antenna housing has a passive antenna assembly that cooperates with the active antenna module.

An ultra-wideband dual-polarized tightly coupled bowtie antenna array for ground-based polar ice sounding radar is described. The antenna array has a very large effective aperture to increase the directivity. At the same time, it is lightweight and low profile to minimize the payload and maximize the survey range. In an implementation, the antenna array operates between 180-620 MHz with a fractional bandwidth of 3.4:1. The broadband performance benefits from the tightly coupled antenna elements. A feature of the antenna array is the planar feeding structure without balun. The antenna array element has the microstrip feeding line integrated with one arm of the bowtie antenna. The other arm is directly fed by the microstrip line. By adding a ferrite core around the coax cable for common mode suppression, the bowtie antenna element can be fed differentially without using bulky vertical feeding structure and balun.

An ultra-wideband dual-polarized tightly coupled bowtie antenna array for ground-based polar ice sounding radar is described. The antenna array has a very large effective aperture to increase the directivity. At the same time, it is lightweight and low profile to minimize the payload and maximize the survey range. In an implementation, the antenna array operates between 180-620 MHz with a fractional bandwidth of 3.4:1. The broadband performance benefits from the tightly coupled antenna elements. A feature of the antenna array is the planar feeding structure without balun. The antenna array element has the microstrip feeding line integrated with one arm of the bowtie antenna. The other arm is directly fed by the microstrip line. By adding a ferrite core around the coax cable for common mode suppression, the bowtie antenna element can be fed differentially without using bulky vertical feeding structure and balun.

An electronic device may be provided with a phased antenna array on an antenna module. The array may include low band antennas and high band antennas that radiate at frequencies greater than 10 GHz. The module may include antenna layers, transmission line layers, and ground traces that separate the antenna layers from the transmission line layers. The low band antennas and the high band antennas may have radiators patterned onto the antenna layers. The radiators may be fed by transmission lines on the transmission line layers. The antenna layers may have a dielectric permittivity that is greater than the dielectric permittivity of the transmission line layers. This may serve to reduce the lateral footprint of the low band and high band antennas, which allows the antennas to be interleaved along a common linear axis in the phased antenna array, thereby minimizing the lateral footprint of the antenna module.

A radar system having a transmitting antenna including a plurality of linear arrays of transmitting antenna elements arranged on a generatrix of a truncated cone or on a cylindrical surface; a signal generator block operatively connected to the transmitting antenna and adapted to feed the transmitting antenna; a receiving antenna having a plurality of groups of linear arrays of receiving antenna elements arranged on the generatrix of the truncated cone or on the cylindrical surface, in which each group of linear arrays of receiving antenna elements is circumferentially interposed between a first and a second linear array of transmitting antenna elements; a signal processor operatively connected to the receiving antenna, where the signal generator block is adapted and configured to feed the transmitting antenna so that the first and the second linear arrays of transmitting antenna elements emit a first and a second electromagnetic radiation, respectively, at a first and a second frequencies different from each other.

A radar system having a transmitting antenna including a plurality of linear arrays of transmitting antenna elements arranged on a generatrix of a truncated cone or on a cylindrical surface; a signal generator block operatively connected to the transmitting antenna and adapted to feed the transmitting antenna; a receiving antenna having a plurality of groups of linear arrays of receiving antenna elements arranged on the generatrix of the truncated cone or on the cylindrical surface, in which each group of linear arrays of receiving antenna elements is circumferentially interposed between a first and a second linear array of transmitting antenna elements; a signal processor operatively connected to the receiving antenna, where the signal generator block is adapted and configured to feed the transmitting antenna so that the first and the second linear arrays of transmitting antenna elements emit a first and a second electromagnetic radiation, respectively, at a first and a second frequencies different from each other.

An antenna device includes a power feeding portion; and an antenna including first and second antenna parts, and an amplifier each electrically connected to the power feeding portion. The first antenna part includes a first element including a part extending in a first direction, and a first loop element connected to an end of the first element. The second antenna part includes a second element including a part extending in the first direction, and a second loop element connected to an end of the second element. The first loop element includes a part extending in the first direction, and a part extending in the second direction different from the first direction. The second loop element includes a part extending in the first direction, and a part extending in a third direction opposite to the second direction. The first and second loop elements are positioned apart from each other.

The present disclosure relates to a reader, such as a reader for a physical access control system. The reader can include first and second antennas, each designed or configured for receiving ultra-wide band (UWB) signals. The reader can also include a mounting plane configured for mounting the reader to a surface. An axis aligning the first and second antennas can be arranged substantially perpendicular relative the mounting plane. A material can be provided between the first and second antennas The material can have a thickness that defines a distance between the first and second antennas of less than a half wavelength of the UWB signal through air (λ.sub.A/2), the material configured to slow down electromagnetic waves passing therethrough such that the thickness of the material provides an effective separation distance of the first and second antennas of at least a half wavelength of the UWB signal through air (λ.sub.A/2).

Remote compensators for mobile devices are provided. In certain embodiments, a mobile device includes a cable-side circulator, an antenna, receive amplifier circuitry that amplifies a receive signal from the antenna and provides an amplified receive signal to the cable-side circulator, transmit amplifier circuitry that amplifies a transmit signal from the cable-side circulator, and a first antenna-side circulator and a second antenna-side circulator each coupled between the transmit amplifier circuitry and the antenna. The first antenna-side circulator and the second antenna-side circulator operate to compensate the receive signal for transmit leakage arising from the transmit amplifier circuitry.

Remote compensators for mobile devices are provided. In certain embodiments, a mobile device includes a cable-side circulator, an antenna, receive amplifier circuitry that amplifies a receive signal from the antenna and provides an amplified receive signal to the cable-side circulator, transmit amplifier circuitry that amplifies a transmit signal from the cable-side circulator, and a first antenna-side circulator and a second antenna-side circulator each coupled between the transmit amplifier circuitry and the antenna. The first antenna-side circulator and the second antenna-side circulator operate to compensate the receive signal for transmit leakage arising from the transmit amplifier circuitry.