EP-4740263-A1 - WAVEGUIDE POLARIZER, CONTACTLESS SIGNAL TRANSMISSION SYSTEM AND ANTENNA DEVICE COMPRISING THE WAVEGUIDE POLARIZER

EP4740263A1EP 4740263 A1EP4740263 A1EP 4740263A1EP-4740263-A1

Abstract

Provided is a system for contactless signal transmission through a rotary joint including a transmitter on a first part of the rotary joint and a receiver on a second part of the rotary joint, the first and second parts being opposite and separated by an air gap, surfaces of the first and second parts facing each other being perpendicular to a rotation axis of the rotary joint, and a choke in the air gap contacting one of the first and second parts, the choke including a printed circuit board having a through hole coaxial with the rotation axis, and an electromagnetic chip, each of the transmitter and the receiver includes a hollow waveguide, at least the transmitter includes in a waveguide polarizer, a diameter of the waveguide polarizer being smaller than a diameter of the round hollow waveguide, and two longitudinal diametrically opposite grooves in walls of the waveguide polarizer.

Inventors

LUKYANOV, ANTON SERGEEVICH
CHERNOKALOV, Alexander Gennadievich
RYU, YOUNGHO
LEE, CHONGMIN

Assignees

Samsung Electronics Co., Ltd.

Dates

Publication Date: 20260513
Application Date: 20241022

Claims (15)

A system for contactless signal transmission through a rotary joint, comprising: a transmitter on a first part of the rotary joint and a receiver on a second part of the rotary joint, the first part of the rotary joint and the second part of the rotary joint being opposite each other and separated by an air gap, a surface of the first part and a surface of the second part facing each other being perpendicular to a rotation axis of the rotary joint; and a choke in the air gap between the first part of the rotary joint and the second part of the rotary joint and contacting one of the first part of the rotary joint and the second part of the rotary joint, the choke comprising a printed circuit board having a circular through hole coaxial with the rotation axis of the rotary joint, and an electromagnetic chip having an electromagnetic bandgap adjacent to the hole in the printed circuit board, the choke being configured to prevent signal leakage through the air gap, wherein each of the transmitter and the receiver comprises a round hollow waveguide aligned with the rotation axis, wherein at least the transmitter comprises in a waveguide polarizer which is a portion of the round hollow waveguide, a diameter of the waveguide polarizer being smaller than a diameter of the round hollow waveguide, and wherein two longitudinal diametrically opposite grooves are formed in walls of the waveguide polarizer.
The system for contactless signal transmission of claim 1, wherein the length of the waveguide polarizer is a multiple of λ g /2 , where λ g is a central wavelength of the signal operating range in the round hollow waveguide.
The system for contactless signal transmission of claim 1, wherein a bottom surface of the grooves coincides with inner walls of the round hollow waveguide.
The system for contactless signal transmission of claim 1, wherein the grooves extend along an entire length of the waveguide polarizer.
The system for contactless signal transmission of claim 1, wherein a diameter of the hole in the printed circuit board is equal to a diameter of the round hollow waveguide in the transmitter and the receiver.
The system for contactless signal transmission of claim 1, wherein a distance from the hole in the printed circuit board of the choke to the EBG structure is a multiple of λ/4, where λ is a central wavelength of the signal operating range in a plane-parallel waveguide formed based on surfaces of the first part and the second part and the choke.
The system for contactless signal transmission of claim 1, wherein the EBG structure is adjacent to the hole in the printed circuit board of the choke.
The system for contactless signal transmission of claim 1, wherein the EBG structure comprises at least two rows of mushroom-EBG (M-EBG) elements, each M-EBGs comprising a conductive pad on the outer layer of the printed circuit board, and a cylinder base formed by a metallized via and connecting the conductive pad to a conductive ground layer included in the printed circuit board.
The system for contactless signal transmission of claim 8, wherein the gap between the choke and each of the first part of the rotary joint and the second part of the rotary joint is less than or equal to λ/4, where λ is the central wavelength of the signal operating range in a plane-parallel waveguide formed based on the surfaces of first part and the second part and the choke.
The system for contactless signal transmission of claim 9, wherein the printed circuit board of the choke comprises four metallized conductive layers alternately disposed with dielectric layers, and wherein the EBG structure is on both sides of the printed circuit board.
The system for contactless signal transmission of claim 10, wherein the M-EBG elements on opposite sides of the printed circuit board are interconnected by a via.
The system for contactless signal transmission of claim 8, wherein the choke is directly on one of the surfaces of the first part and the second part.
The system for contactless signal transmission of claim 12, wherein the printed circuit board of the choke comprises two metallized conductive layers with a dielectric layer between the two metallized conductive layers, and wherein the EBG structure is on a side of the printed circuit board that is separated by the air gap from the surface of the other of the surfaces of the first part and the second part, based on electrical contact being provided between a ground layer of the choke and the surface of said one of the rotary joint parts.
The system for contactless signal transmission of claim 1, wherein the receiver comprises a waveguide polarizer in the round waveguide.
The system for contactless signal transmission of claim 1, wherein the signal is a data signal for data transmission through the rotary joint.

Description

WAVEGUIDE POLARIZER, CONTACTLESS SIGNAL TRANSMISSION SYSTEM AND ANTENNA DEVICE COMPRISING THE WAVEGUIDE POLARIZER Embodiments of the present disclosure relate to a rotary joint comprising a waveguide polarizer, and to a contactless signal transmission system and an antenna device comprising said waveguide polarizer. The rapid growth of robotics technologies is currently based on the growing need for automated and robotic complexes in various areas of human activity, such as the military, industry, mining, etc., in which requires development of structures for transmitting signals to and from actuators of the robotic complex (robot) through parts (joints) of the robot. Such development is especially important for rotating parts, such as rotating robot joints. At present, there are several ways to organize the transmission of signals through rotary joints. For example, cable assemblies may be used to transmit signals. In the assemblies, the cable passes through a rotary joint. However, cable assemblies may have a number of disadvantages, including a limited rotation range of the joints, relatively low reliability of the cable due to torque, relatively high probability of cable damaging during intense movements, etc. Rotary contacts (slip rings)may be used, but rotary contacts are not suitable for high data rates (HD video, etc.), have relatively low reliability, may lead to interference due to sparking between contacts, and degrade with time due to mechanical wear. In addition, mechanical part of the rotary contact may require high-precision manufacture. High-frequency rotary joints based on split coaxial or round waveguides may also be used. However, high-frequency rotary joints may often have full-metal bulky designs suitable only for stationary objects, and require complex and high-precision assembly. In addition, high-frequency rotary joints may provide only a half-duplex channel connection per line. The use of circular polarized signals for data transmission may enable full-duplex and multi-channel communication due to its symmetry, and therefore may be used in rotary couplings. The polarizer may more easily provide a circular polarized signal in round waveguide that, due to its symmetry, may allow the efficient propagation of a circular polarized signal. A microwave rotating coupling for rectangular waveguide for connecting high-frequency components may include an input component and an output component, where each component has a rectangular connecting piece at one end and a round waveguide at the other end. Both components are arranged such that the round waveguides facing each other are rotatably mounted in a coupling transition coaxially about the common axis (A) thereof. The microwave rotating coupling for rectangular waveguide may also include a polarizer, by which at least one linear polarized wave can be transduced to a circular polarized or at least one circular polarized wave can be transduced to a linear polarized wave, is provided between the rectangular connecting piece and circular waveguide. Furthermore, the rectangular connecting pieces are arranged axially to the circular waveguides and at least one rectangular waveguide may be connected in parallel to the axis (A). However, the microwave rotating coupling for rectangular waveguide may have a bulky design. A dual-band circular polarizer for simultaneously transforming two to four linear polarized waves of two different frequency bands into two to four circular polarized waves, and vice versa may be provided. The polarizer may include a waveguide of circular or square cross-sectional shape dimensioned to simultaneously propagate signals in two different frequency bands and two arrays of conductive elements, each array comprising a pair of diametrically opposed rows of conductive elements extending inwardly from the walls of the waveguide. However, the polarizer may be difficult to manufacture, as may require conductive elements used in the waveguide, and holding elements for dielectric polarizer in waveguide. The dielectric polarizer may introduce additional losses during signal transmission. Moreover, polarizer may only provide half-duplex communication. Multichannel microwave rotary coupling may include single-channel rotary joints mounted coaxially one above another, each based on a coaxial line with quarter-wave short-circuited loops in the form of a radial line and matching transitions at ends. Outer and central conductors of the coaxial line comprise quarter-wave choke clearances, radial line has variable height, and a hollow metal rod of cylinder shape passes through central conductors of single-channel couplings from rotating to stationary part of the structure, which forms choke clearances with fixed central conductors. Movable inputs of single-channel rotary couplings are brought to the rotating part of the device structure by means of coaxial feeders, passing, except for the feeder of the upper single-channel coupling,