A first band radiating element for a multi-band antenna comprises at least one first band dipole that has a first dipole arm and a second dipole arm that each include one or more arm segments, and the number of the arm segments of the first dipole arm is greater than the number of the arm segments of the second dipole arm.

A dipole antenna is disclosed. The dipole antenna includes a first arm, a second arm, and a first conductive plate. The first conductive plate is placed inside one of the first arm or the second arm. The first conductive plate creates a cavity inside the one of the first arm or the second arm.

A dipole antenna is disclosed. The dipole antenna includes a first arm, a second arm, and a first conductive plate. The first conductive plate is placed inside one of the first arm or the second arm. The first conductive plate creates a cavity inside the one of the first arm or the second arm.

The invention relates to an antenna structure for transmitting and/or receiving wavelengths of metric frequency or decimetric frequency, characterised in that it comprises n collinear antennas, each antenna comprising a radiating portion comprising a first succession of i coaxial radiating elements about a first axis alternating with at least an additional succession of i radiating elements about another axis, each antenna being independently powered by a coaxial cable, each antenna comprising at least one lower quarter-wave trap and at least one upper quarter-wave trap, at least a first antenna comprising at least one hollow core being configured to receive a coaxial cable intended for powering of another antenna collinear with the first antenna, at least one intermediate quarter-wave trap being arranged between two consecutive collinear antennas around a coaxial cable, and a terminal element.

A sum and difference mode antenna includes a first radiator, a second radiator, a first excitation source, and a second excitation source. The first radiator includes a first segment, a second segment, and a gap formed between the first segment and the second segment, and the first excitation source is configured to feed the first radiator, so that currents in the first segment and the second segment both flow in a first direction. The second radiator includes a third segment, a fourth segment, and a fifth segment. The third segment and the fourth segment are symmetrically distributed on two sides of a connection end of the fifth segment, and the second excitation source is electrically connected to a feed end of the fifth segment to feed the second radiator.

A sum and difference mode antenna includes a first radiator, a second radiator, a first excitation source, and a second excitation source. The first radiator includes a first segment, a second segment, and a gap formed between the first segment and the second segment, and the first excitation source is configured to feed the first radiator, so that currents in the first segment and the second segment both flow in a first direction. The second radiator includes a third segment, a fourth segment, and a fifth segment. The third segment and the fourth segment are symmetrically distributed on two sides of a connection end of the fifth segment, and the second excitation source is electrically connected to a feed end of the fifth segment to feed the second radiator.

An antenna apparatus includes a ground layer, a wiring layer spaced apart from either a first surface or a second surface of the ground layer and including wiring lines, feed lines electrically connected to the wiring lines, a dipole antenna pattern to transmit and/or receive an RF signal, a plurality of feed vias to electrically connect poles of the dipole antenna pattern to the feed lines, and a ground pattern to electrically connect the poles of the dipole antenna pattern to the ground layer.

An antenna apparatus includes a ground layer, a wiring layer spaced apart from either a first surface or a second surface of the ground layer and including wiring lines, feed lines electrically connected to the wiring lines, a dipole antenna pattern to transmit and/or receive an RF signal, a plurality of feed vias to electrically connect poles of the dipole antenna pattern to the feed lines, and a ground pattern to electrically connect the poles of the dipole antenna pattern to the ground layer.

A microwave-doppler detecting module and device thereof are provided, wherein the microwave-doppler detecting module includes an electromagnetic reflecting surface and at least a pair of antithetical dipoles spacingly disposed to the electromagnetic reflecting surface. When the first and second radiating source poles respectively extended from a first and second feed ends of the pair of antithetical dipoles are respectively fed by the same excitation signal feed source at the first feed end and the second feed end, the current and the potential distribution of the first radiating source pole and the second radiating source pole can present an antithetical distribution state and antithetically coupled to the midpoint of the connection of the first feed end and the second feed end, so as to reduce the size requirement of the microwave-doppler detecting module and to avoid detection dead zone from occurring.

A liquid crystal antenna unit and a liquid crystal phased array antenna are provided. The liquid crystal antenna unit includes: a first substrate, a second substrate opposite to the first substrate, a liquid crystal layer between the first substrate and the second substrate, a transmission line on a first surface and extending in a first direction along the first surface, a first antenna oscillator on the first surface and arranged as an elongated dipole extending in a second direction along the first surface, a second antenna oscillator on a surface of the second substrate distal to the first substrate and at a position corresponding to the first antenna oscillator, and a ground electrode on a surface of the first substrate distal to the second substrate.