Base station antennas include an externally accessible active antenna module releasably coupled to a recessed segment that is over a chamber in the base station antenna and that is longitudinally and laterally extending along and across a rear of a base station antenna housing. The base station antenna housing has a passive antenna assembly that cooperates with the active antenna module.

Antennas include first and second radiating elements that are configured to operate in respective operating frequency bands. The first radiating element includes a first dipole arm that has a first conductive path and a second conductive path that is positioned behind the first conductive path. The first conductive path includes a plurality of first segments and the second conductive path includes a plurality of second segments, where a subset of the first segments overlap respective ones of second segments to form a plurality of pairs of overlapping first and second segments. At least some of the pairs of overlapping segments are configured so that the instantaneous direction of a first current formed on the first segment in response to RF radiation emitted by the second radiating element will be substantially opposite the instantaneous direction of a second current formed on the second segment in response to the RF radiation.

A chip-implementation of a millimeter wave MIMO radar comprises transmitters for transmitting short bursts of digitally modulated radar carrier signals and receivers for receiving delayed echoes of those signals. Various signal formats defined by the number of bits per transmit burst, the transmit burst duration, the receive period duration, the bitrate, the number of range bins, and the number of bursts per scan, facilitate the choice of modulating bit patterns such that when correlating for target echoes over an entire scan, the correlation codes for different ranges and different transmitters are mutually orthogonal or nearly so. In the event of imperfect orthogonality, simple orthogonalization schemes are revealed, such as subtraction of strong already-detected target signals for better detecting weaker signals or moving targets that are rendered non-orthogonal by their Doppler shift.

A dual-polarized radiating element for abase station antenna includes a first dipole radiator that comprises a first dipole arm and a third dipole arm and a second dipole radiator that comprises a second dipole arm and a fourth dipole arm. The radiating element further includes a first inductor that is coupled between the first dipole arm and the second dipole arm.

A radiating element includes a radiator mounted on a feed stalk. The radiator includes a first dipole having first and second dipole arms and a second dipole having third and fourth dipole arms, where the first and second dipoles are in a cross-dipole arrangement. Each of the dipole arms includes a trunk conductive segment and a branch conductive segment, where one end of the branch conductive segment is connected to the trunk conductive segment and the other end is open. The branch conductive segment is configured such that a current induced by radiation in a preselected frequency range higher than an operating frequency range of the radiating element in a portion, to which the branch conductive segment is connected, of the trunk conductive segment of the dipole arm is opposite to a current induced in the branch conductive segment.

A reconfigurable antenna includes a bottom plate, a vertically polarized high-density antenna, and a controllable reflector. The controllable reflector is located between the bottom plate and the vertically polarized high-density antenna, and a projection of the controllable reflector on the bottom plate is at a center of a projection of the vertically polarized high-density antenna on the bottom plate. The controllable reflector includes a switch, and the switch is configured to enable the controllable reflector to be in an operating state or an off state.

Systems and methods are provided for a digital beamformed phased array feed. The system may include a radome configured to allow electromagnetic waves to propagate; a multi-band software defined antenna array tile; a power and clock management subsystem configured to manage power and time of operation; a thermal management subsystem configured to dissipate heat generated by the multi-band software defined antenna array tile; and an enclosure assembly. The multi-band software defined antenna array tile may include a plurality of coupled dipole array antenna elements; a plurality of frequency converters; and a plurality of digital beamformers.

This disclosure presents an antenna device including one or more arrays of radiating elements, wherein each array may be an end-fire array. The antenna device comprises an array of N radiating elements (N>1) arranged on a common axis. Each radiating element is configured to radiate a radio wave in response to a RF signal fed to the respective radiating element. A reflector is arranged on the common axis to reflect the N radio waves into a main radiating direction. The antenna device comprises a feed structure to feed a RF signal to each radiating element. The RF signal at each radiating element has a respective phase difference relative to the RF signal at a first radiating element. The feed structure comprises one or more phase shifters, for one or more or all radiating elements, to set the phase difference of the RF signal at the respective radiating element.

A twin beam base station antenna includes a first array that has a plurality of columns of first frequency band radiating elements, the first array configured to form a first antenna beam that provides coverage throughout a first sub-sector of a three-sector base station. The radiating elements in a first of the columns in the first array have a first azimuth boresight pointing direction and the radiating elements in a second of the columns in the first array have a second azimuth boresight pointing direction that is offset from the first azimuth boresight pointing direction by at least 10°. The radiating elements in the second of the columns in the first array are electrically steered.

A dipole antenna includes a reflector, a radiating element, and a feed element. The radiating element includes first and second dipoles above a surface of the reflector. The first and second dipoles respectively include arm segments and are arranged in a crossed dipole arrangement. The feed element includes first and second conductive transmission lines that are electrically isolated from one another and are capacitively coupled to the arm segments of the first and second dipoles, respectively. The arm segments of the first and second dipoles are between the feed element and the surface of the reflector.