The present disclosure relates to a phase shifter, an antenna, and a radio communications device. One example phase shifter includes a cavity, a rotating shaft, a main printed circuit board (PCB), a first slidable part, and a second slidable part. The first slidable part is located on a front side of the main PCB and coupled to the main PCB. The second slidable part is located on a rear side of the main PCB and coupled to the main PCB. The rotating shaft is inserted into the cavity and connected to the first slidable part and the second slidable part. The first arc-shaped phase delay line and the second arc-shaped phase delay line are distributed on a circle with a center that is the same as a center of the rotating shaft, and are located on an outer side of a primary central coupling section.

A miniaturized multi-sectioned, directional coupler using a multi-layer MMIC process, the coupler comprising, a monolithic microwave integrated circuit, having a central section with a relatively tight coupling, surrounded by sections of lighter coupling, the relatively tight coupling being comprised of a pair of spiral coupled lines, and the lighter coupling being comprised of meandered edge couple lines with capacitive loading of the lines in several places.

A high-frequency transmission line in which the alternating-current resistance is low is provided. A high-frequency transmission line 2 is a high-frequency transmission line 2 to transmit an alternating-current electric signal, and contains metal and carbon nanotube, and the carbon nanotube is unevenly distributed at a peripheral part 8 of a cross-section that is of the high-frequency transmission line 2 and that is perpendicular to a transmission direction of the alternating-current electric signal.

The present invention relates to a phase shifter having low loss in broadband, and a wireless communication device comprising same. The wireless communication device according to one embodiment comprises: a wireless communication module; a first antenna; a first transmission line for allowing the transmission of a signal between the wireless communication module and the first antenna; and a phase shifting element arranged in series on the first transmission line, wherein the phase shifting element is stacked in the vertical direction and can include a plurality of resonant unit elements electrically connected in parallel to one another.