Bending compensation for molded waveguide antennas

Abstract

The invention relates to bend compensation for molded waveguide antennas. A radio frequency (RF) system includes a control printed circuit board (control PCB) configured to generate an RF signal. A waveguide antenna is attached to the control PCB and includes an input channel that receives an RF signal along a first axis. The curved transition chamber receives the RF signal from the input channel and transmits the RF signal to the waveguide channel. The waveguide channel receives the RF signal along a second axis orthogonal to the first axis and transmits the RF signal to a radiator that transmits the RF signal to the outside of the RF system. The curved transition chamber includes a short chamber having a width along a third axis orthogonal to both the first axis and the second axis that is greater than a width of the input channel along the third axis and greater than a width of the waveguide channel along the third axis.

Description

Technical Field

[0001] The present disclosure relates to a molded waveguide antenna, including a molded waveguide antenna that includes bend compensation for transitioning from a vertical waveguide input from a printed circuit board (PCB) to a horizontal waveguide channel that provides a path to a radiator of the antenna, such as a waveguide antenna for a radio frequency (RF) system that includes a transmitter and / or a receiver. Background Art

[0002] This section provides background information related to the present disclosure, which is not necessarily prior art.

[0003] Some radio frequency (RF) systems, such as automotive radar systems and / or communication systems, use printed circuit board (PCB) antennas, where the RF system includes a control PCB that includes processing components for the system, such as one or more microprocessors, one or more power supplies, other integrated circuits (ICs), etc., and an additional antenna PCB attached to the control PCB. The additional antenna PCB is made of a high-performance RF material and includes antenna components that serve as antennas for the radar system. The PCB antenna radiator can be implemented using, for example, microstrip patches, microstrip stubs, microstrip meander lines, etc. The antenna PCB can be adhered to the control PCB with an adhesive.

[0004] Alternatively, in other configurations, some existing systems include RF material located on the control PCB itself that serves as an antenna for the radar system without using an additional antenna PCB.

[0005] A waveguide antenna can be used instead of the PCB-type antenna of the RF system. For example, a molded waveguide component can be attached to the control PCB. The molded waveguide component can include an input bend interface to direct RF power received from a vertical input channel connected to the control PCB to a horizontal waveguide channel that delivers the RF power to a radiator output of the radar antenna.

[0006] However, a right-angle bend at the transition from the vertical input channel to the horizontal waveguide channel may cause a loss of radar RF signal power due to reflected power at the right-angle bend. Referring Figures 11A to 11D , existing systems have attempted to reduce the power loss caused by the right-angle bend by adding a chamfer or radius to the outer edge of the bend, which reduces the width of the waveguide in an attempt to transfer more RF power from the vertical input channel to the horizontal waveguide channel. For example, Figure 11A shows an angled chamfer at the outer edge of the bend, which reduces the capacitance in the corner of the right-angle bend. Figure 11B shows a curved outer edge of the bend, where the radius curve of the outer edge is greater than the width of the vertical and horizontal channels. Figure 11CShows the curved outer edge of the bend, whose radius is similar to the widths of the vertical and horizontal channels. Figure 11D Shows a bend having both a curved inner edge and an outer edge to convert RF power from a vertical input of a control PCB to a horizontal channel of a waveguide.

[0007] In a waveguide antenna composed of molded components, when the waveguide is oriented to be separated at the midpoint of the E-plane of the waveguide between the upper and lower halves, the minimum power is lost due to the inevitable gaps between the components. In an RF system, the E-plane refers to the plane containing the electric field vector and the direction of maximum radiation. The E-plane is 90 degrees different from the H-plane, which is the plane containing the magnetic field vector. Using chamfers or bend radii within a right-angle bend can make the molded components of the waveguide asymmetric, which results in power loss. Conductive paste or solder can be used to attach two molded components of the waveguide together, but using conductive paste or solder to attach the molded components together results in an increase in cost. Alternatively, some existing systems have utilized an iris within the vertical input channel to reduce the width of a portion of the vertical input channel. In this way, the iris restricts and reduces the width of a small portion of the input channel of the waveguide to create a capacitance or inductance that partially offsets the effects of the right-angle bend. However, this diaphragm method of reducing the width region of the vertical channel requires specific manufacturing tolerances, which may be difficult to manufacture with molded components. SUMMARY OF THE INVENTION

[0008] This section provides an overall overview of the present disclosure and is not an exhaustive disclosure of its full scope or all of its features.

[0009] A radio frequency (RF) system is provided and includes: a control printed circuit board (PCB) that includes a processor and a transmitter configured to generate RF signals; and a waveguide antenna attached to the control printed circuit board. The waveguide antenna includes an input channel, a curved transition chamber, a waveguide channel, and a radiator. The input channel is configured to receive RF signals from the control PCB along a first axis. The curved transition chamber is configured to receive RF signals from the input channel and route the RF signals to the waveguide channel. The waveguide channel is configured to receive RF signals from the curved transition chamber along a second axis orthogonal to the first axis and transmit the RF signals to the radiator. The radiator is configured to transmit RF signals outside the RF system. The curved transition chamber includes a short chamber having a width along a third axis that is orthogonal to both the first axis and the second axis, the width being greater than the width of the input channel along the third axis and greater than the width of the waveguide channel along the third axis.

[0010] In other features, the waveguide antenna includes an upper waveguide portion and a lower waveguide portion both formed by a molding process.

[0011] Among other features, the upper waveguide portion includes an upper chamber, and the lower waveguide portion includes a lower chamber such that when the upper waveguide portion and the lower waveguide portion are assembled together, the curved transition chamber is formed by the upper chamber and the lower chamber.

[0012] Among other features, the upper chamber and the lower chamber are symmetric along a plane formed by a second axis and a third axis.

[0013] Among other features, the upper waveguide portion includes an upper waveguide part, and the lower waveguide portion includes a lower waveguide part such that when the upper waveguide portion and the lower waveguide portion are assembled together, the waveguide channel is formed by the upper waveguide part and the lower waveguide part.

[0014] Among other features, the upper waveguide part and the lower waveguide part are symmetric along a plane formed by a second axis and a third axis.

[0015] Among other features, the upper waveguide portion and the lower waveguide portion are assembled together in an automotive radar system without conductive paste and solder.

[0016] Among other features, the short chamber includes a first protrusion extending along the third axis from a first sidewall of the curved transition chamber and a second protrusion extending from a second sidewall of the curved transition chamber opposite the first sidewall.

[0017] Among other features, the first protrusion and the second protrusion extend equal distances from the first sidewall and the second sidewall, respectively.

[0018] Among other features, the first protrusion and the second protrusion extend different distances from the first sidewall and the second sidewall, respectively.

[0019] Among other features, the short chamber includes only a protrusion extending along the third axis from a first sidewall of the curved transition chamber, and the second sidewall opposite the first sidewall does not include a protrusion.

[0020] Among other features, a PCB and a waveguide antenna are included in an automotive radar system configured to transmit and receive radar signals.

[0021] Another radio frequency (RF) system is provided, and the system includes: a control printed circuit board (PCB) including a processor and a transmitter configured to generate an RF signal; and a waveguide antenna attached to the control PCB. The waveguide antenna includes an input channel, a bent transition chamber, a waveguide channel, and a radiator. The input channel is configured to receive the RF signal from the control PCB along a first axis. The bent transition chamber is configured to receive the RF signal from the input channel and transmit the RF signal to the waveguide channel. The waveguide channel is configured to receive the RF signal from the bent transition chamber along a second axis orthogonal to the first axis and transmit the RF signal to the radiator. The radiator is configured to transmit the RF signal outside the RF system. The bent transition chamber includes a short chamber having a width along a third axis orthogonal to both the first axis and the second axis, the width being greater than the width of the input channel along the third axis and greater than the width of the waveguide channel along the third axis. The waveguide antenna includes an upper waveguide portion and a lower waveguide portion formed by a molding process. The upper waveguide portion includes an upper chamber, and the lower waveguide portion includes a lower chamber such that when the upper waveguide portion and the lower waveguide portion are assembled together, the bent transition chamber is formed by the upper chamber and the lower chamber. The upper waveguide portion includes an upper waveguide part, and the lower waveguide portion includes a lower waveguide part such that when the upper waveguide portion and the lower waveguide portion are assembled together, the waveguide channel is formed by the upper waveguide part and the lower waveguide part. The upper waveguide portion and the lower waveguide portion are assembled together in an automotive radar system without conductive paste and solder.

[0022] In other features, the short chamber includes a protrusion extending along the third axis from a sidewall of the bent transition chamber.

[0023] In other features, the short chamber includes a first protrusion extending along the third axis from a first sidewall of the bent transition chamber and a second protrusion extending from a second sidewall of the bent transition chamber opposite the first sidewall, wherein the first protrusion and the second protrusion extend equal distances from the first sidewall and the second sidewall, respectively.

[0024] Based on the description provided herein, other applicable fields will become apparent. The description and specific examples in the present disclosure are only for illustrative purposes and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are only for illustrative purposes of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0026] Figure 1 is an exploded view of a radar system according to the present disclosure.

[0027] Figure 2 is a cross-sectional view of a radar system according to the present disclosure.

[0028] Figure 3is a perspective view of a waveguide antenna according to the present disclosure.

[0029] Figure 4 is a perspective view of an upper waveguide portion of a waveguide antenna according to the present disclosure.

[0030] Figure 5 Shows an input channel, a bent transition chamber, and a waveguide channel of a waveguide antenna according to the present disclosure.

[0031] Figure 6 Shows an input channel, a bent transition chamber, and a waveguide channel of a waveguide antenna according to the present disclosure.

[0032] Figure 7 is a top view of a bent transition chamber of a waveguide antenna according to the present disclosure.

[0033] Figure 8 is a graph showing the return loss of a radar system configured with a bent transition chamber according to the present disclosure.

[0034] Figure 9 is a top view of another embodiment of a bent transition chamber of a waveguide antenna according to the present disclosure.

[0035] Figure 10 is a top view of another embodiment of a bent transition chamber of a waveguide antenna according to the present disclosure.

[0036] Figures 11A to 11D Shows an existing system for transmitting an RF signal from a vertical input channel to a horizontal waveguide channel.

[0037] Figure 12 Shows a vehicle having a radar system according to the present disclosure.

[0038] Throughout several views of the drawings, corresponding reference numerals indicate corresponding components. Detailed Description

[0039] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0040] The present disclosure relates to a waveguide antenna for an RF system, including, for example, an automotive radar system, a communication system, etc., which includes bend compensation for transitioning from a vertical waveguide input channel extending from an RF input of a printed circuit board (PCB) to a horizontal waveguide channel that provides a route for an RF signal from the input channel to one or more radiators of the antenna. The bend compensation includes a vertical-to-horizontal bend transition chamber that includes a short chamber having sidewalls that project outwardly from the bend transition chamber such that the width of the bend transition chamber within the short chamber is greater than the width of the vertical input channel and greater than the width of the horizontal waveguide channel. Compared to existing systems, the wider short chamber at the junction / transition interface of the bend transition chamber provides technical advantages over existing systems, including better RF performance loss and greater bandwidth capabilities. As discussed further in detail below, the wider short chamber at the junction / transition interface also does not have the manufacturing and fabrication limitations imposed by the tight tolerances of existing iris methods that utilize a narrowing of the vertical chamber walls. As discussed further in detail below, the waveguide antenna of the present disclosure includes two molded parts that are symmetric about a horizontal waveguide centerline, resulting in low leakage without the need to use a conductive paste of solder to hold the two molded parts together. In this way, using a wider short chamber at the vertical-to-horizontal junction / transition interface of the waveguide between the vertical input channel from the control PCB to the horizontal waveguide channel for transmitting RF to the radar antenna increases the amount of RF power that is emitted from the control PCB through the junction / transition interface into the horizontal waveguide channel and ultimately to the radiators of the radar antenna.

[0041] Reference Figure 1 and Figure 2 , radar system 10 is shown and includes a control PCB 12 that includes processing components for the radar system 10, such as one or more microprocessors, one or more power supplies, other integrated circuits (ICs) having one or more transmitters, one or more receivers, etc., for generating and transmitting RF radar signals for detecting targets in a vehicle environment. While radar system 10 is provided as an example, the molded waveguide antenna of the present disclosure can be used with other RF systems that include transmitters and / or receivers, such as communication systems. Radar system 10 includes a lower housing 14 and an upper housing 16 that house the components of radar system 10 when assembled. Once assembled, radar system 10 includes a waveguide antenna 18 that is housed within lower housing 14 and upper housing 16. Waveguide antenna 18 includes two pieces or halves, including an upper waveguide portion 20 and a lower waveguide portion 22.

[0042] The upper waveguide portion 20 and the lower waveguide portion 22 of waveguide antenna 18 are molded parts that are assembled together without the need for a conductive paste or solder. As Figure 2As shown, a side view of the waveguide antenna 18 shows that the upper waveguide portion 20 and the lower waveguide portion 22 are configured such that the waveguide antenna 18 is separated along the horizontal plane of the route of the waveguide antenna 18 to minimize leakage in the case where there is any gap between the upper waveguide portion 20 and the lower waveguide portion 22. The lower waveguide portion 22 of the waveguide antenna 18 is attached to the control PCB 12 and includes a vertical input channel 30 that receives an RF signal from the control PCB 12. As discussed in further detail below, the vertical input channel 30 is connected to a bent transition chamber that transmits the RF signal received from the control PCB 12 to a horizontal waveguide channel, which further transmits the RF signal to the radiator of the waveguide antenna 18.

[0043] Also referring to Figure 3 , an exploded view of the waveguide antenna 18 is shown, and the upper sides of each of the upper waveguide portion 20 and the lower waveguide portion 22 are shown. Also referring to Figure 4 , the lower side of the upper waveguide portion 20 is shown. The upper waveguide portion 20 and the lower waveguide portion 22 are configured such that the matching halves of the corresponding waveguide channels are guided through each of the upper waveguide portion 20 and the lower waveguide portion 20, such that when the upper waveguide portion 20 and the lower waveguide portion 22 are assembled together, the waveguide channel is formed by the matching halves. Each vertical input channel 30 leads, for example, to a bent transition chamber 36 (as shown in Figure 5 and Figure 6 ). The upper chamber 32 of the bent transition chamber 36 is formed in the upper waveguide portion 20, and the lower chamber 34 of the bent transition chamber 36 is formed in the lower waveguide portion 22. When the upper waveguide portion 20 and the lower waveguide portion 22 are assembled together, the upper chamber 32 and the lower chamber 34 form the bent transition chamber 36. The bent transition chamber 36 guides the RF power from the vertical input channel 30 into the horizontal waveguide channel 42 (as shown in Figure 5 and Figure 6 ). The horizontal waveguide channel 42 is formed by an upper waveguide section 38 formed in the upper waveguide portion 20 and a lower waveguide section 40 formed in the lower waveguide portion 22. When the upper waveguide portion 20 and the lower waveguide portion 22 are assembled together, the upper and lower waveguide sections 38 form the horizontal waveguide channel 42.

[0044] Referring again to Figure 3 , the upper side of the lower waveguide portion 22 is shown, showing a plurality of lower chambers 34 and a plurality of lower waveguide sections 40. Referring to Figure 4 , the lower side of the upper waveguide portion 20 is shown, showing a plurality of upper chambers 32 and a plurality of upper waveguide sections 38. When the upper side of the lower waveguide portion 22 mates and attaches to the lower side of the upper waveguide portion 20, each upper chamber 32 and the mating lower chamber 34 form the bent transition chamber 36 (as shown in Figure 5 and Figure 6 ), and each upper waveguide section 38 and the mating lower waveguide section 40 form the horizontal waveguide channel 42 (as shown in Figure 5and Figure 6 as shown).

[0045] Each horizontal waveguide channel 42 leads to a radiator that transmits radar RF from the radar system 10 outward to a target within the vehicle environment. Similar to the curved transition chamber 36 and the horizontal waveguide channel 42, each radiator includes an upper radiator portion 48( Figure 4 as shown) and a lower radiator portion 50( Figure 3 as shown).

[0046] Referring Figures 5 to 7 , RF power is transmitted from the control PCB 12 into the vertical input channel 30. In Figures 5 to 7 , the vertical direction corresponding to the direction of RF power transmission from the control PCB 12 into the vertical input channel is designated as the z-axis. Then, the RF power is transmitted from the vertical input channel 30 into the curved transition chamber 36, where the RF power is transmitted and transitioned into the horizontal waveguide channel 42. The direction of the RF power transmitted through the horizontal waveguide channel 42 is designated as the x-axis in Figures 5 to 7 . In this way, the RF power transmitted from the control PCB 12 is transmitted into the vertical input channel 30 and then, via the curved transition chamber 36, is transmitted into the horizontal waveguide channel 42 through a right-angle transition from the z-axis to the x-axis. The RF power is then transmitted via the horizontal waveguide channel 42 to the corresponding radiator of the radar system 10, as described above.

[0047] In one embodiment, the curved transition chamber 36 includes a short chamber 50 formed by a protrusion 52 in opposite walls of the curved transition chamber 36. The short chamber 50 is formed along at least a portion of the curved transition chamber such that the width of the short chamber 50 in the y-axis direction, which is orthogonal to both the x-axis and the y-axis, is greater than the width of the vertical input channel 30 in the y-axis direction and the width of the horizontal waveguide channel 42 in the y-axis direction. In other words, in the direction orthogonal to both the direction of the RF power transmitted through the vertical input channel 30 and the direction of the RF power transmitted through the horizontal waveguide channel 42, the short chamber 50 is wider than both the horizontal waveguide channel 42 and the vertical input channel 30.

[0048] As Figures 5 to 7 shown, in one embodiment, the length of the short chamber 50 along the x-axis is less than the length of the vertical input channel 30 along the x-axis. Additionally, the length of the short chamber 50 in the x-axis direction is less than the total length of the curved transition chamber 36. However, for different radar applications utilizing different RF wavelengths, the length of the short chamber 50 can be adjusted and regulated. Alternatively, in some embodiments, the length of the short chamber 50 in the x-axis direction can extend fully to be the same as the length of the vertical input channel 30 in the x-axis direction and be the full length of the curved transition chamber 36.

[0049] ReferringFigure 5 , a perspective view of the vertical input channel 30, the curved transition chamber 36, and the horizontal waveguide channel 42 is shown in a model format having sharp edges and corners and no rounded corners. Refer to Figure 7 , a top view of the curved transition chamber 36, the short chamber, and the protrusion 52 is shown in a model form having sharp edges and corners and no rounded corners.

[0050] Reference Figure 6 , in practice, the upper waveguide portion 20 and the lower waveguide portion 22 can be manufactured as molded parts. Therefore, for ease of manufacturing as molded parts, the various channels and chambers can be manufactured to have rounded edges, rounded corners, and a taper in the sidewalls. In this way, the parts can be more easily removed from the mold during the molding process. As Figure 6 shown, a component of Figure 5 is shown, except that, according to the requirements of the molding manufacturing process, it has rounded edges and rounded corners. In this way, Figure 6 a perspective view of the vertical input channel 30, the curved transition chamber 36, and the horizontal waveguide channel 42 is provided, showing the rounded edges and corners and the rounded corners and taper of the sidewalls of the vertical input channel 30, the curved transition chamber 36, and the horizontal waveguide channel 42.

[0051] Compared with the existing system, the radar system 10 of the present disclosure provides improved performance characteristics. The radar system 10 has a curved transition chamber 36 having a short chamber 50 and protrusions 52 in opposite walls of the curved transition chamber 36. In particular, compared with an existing vehicle radar system using, for example, Figures 11A to 11D the right-angle bend configuration shown in

[0052] Reference Figure 8 , a performance curve graph is shown, which shows the echo loss simulation results of a representative curved transition chamber 36 having a short chamber 50 according to the present disclosure over a range of manufacturing tolerances. The indicated echo loss corresponds to the amount of echo loss of the RF power from the vertical input channel 30 to the horizontal waveguide channel 42 through the curved transition chamber 36. In Figure 8 , the echo loss in decibels (dB) is shown on the vertical axis, where a lower echo loss represents better performance with better transmission of the RF power from the vertical input channel 30 to the horizontal waveguide channel 42. The test frequencies used for the simulation are shown in gigahertz (GHz) along the horizontal axis. Automotive radar systems typically can utilize frequencies in the range of 76 to 81 GHz. Symmetric existing solutions are difficult to achieve an echo loss of -15.00 dB, and even if an existing system is tested to have an echo loss of -15.00 dB, in practice, with manufacturing variations, the final maximum echo loss of most systems is closer to -10.00 dB.

[0053] As Figure 8 shown, for the radar system according to the present disclosure, for all analog configurations, the return loss is well below -15.0 dB in the range of 76 to 81 GHz. Figure 8 The different return loss curves shown in represent configurations of component parts having different manufacturing differences (such as gaps, dimensions, and offsets within tolerances) between the upper waveguide portion 20 and the lower waveguide portion 22. In this way, compared to existing systems, the radar system with the curved transition chamber 36 having the short chamber 50 according to the present disclosure exhibits reduced return loss, increased performance, and better RF power transfer from the vertical input channel 30 to the horizontal waveguide channel 42.

[0054] The foregoing embodiments of the present disclosure include the short chamber 50 having projections 52 of equal dimensions on either side of the short chamber 50. In Figure 9 the alternative embodiment shown, the curved transition chamber 36 may be configured with a short chamber having a projection 52 on only one side of the curved transition chamber 36. Additionally, in Figure 10 another alternative embodiment shown, the projections may have different dimensions on either side of the short chamber 50. As Figure 10 shown, one side of the short chamber 50 includes a projection 52 while the opposite side includes a smaller projection 54.

[0055] The foregoing description of the embodiments has been provided for purposes of illustration and description and is not intended to be exhaustive or to limit the present disclosure. The individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but rather, where applicable, are interchangeable and can be used in another embodiment, even if not specifically shown or described. The various embodiments can also vary in many ways. Such variations should not be regarded as a departure from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure. Although each embodiment has been described above as having certain features, any one or more of those features described with respect to any embodiment of the present disclosure can be implemented in and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations and combinations of one or more embodiments with each other are still within the scope of the present disclosure.

[0056] Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Specific details are set forth, including examples of specific components, devices, and methods, to provide a thorough understanding of the embodiments of this disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that the example embodiments may be embodied in many different forms, and that none of them should be construed as limiting the scope of this disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0057] Spatial and functional relationships between elements (such as between modules) can be described in various terms, including "connected", "engaged", "interface", and "coupled". Unless explicitly described as "direct", when describing the relationship between a first element and a second element in the above disclosure, the relationship encompasses a direct relationship where no other intermediate element exists between the first element and the second element, and an indirect relationship where one or more intermediate elements (spatially or functionally) exist between the first element and the second element.

[0058] The phrase "at least one of A, B, and C" should be interpreted as meaning a logical "or" using non-exclusive logic (A or B or C), and should not be interpreted as meaning "at least one of A, at least one of B, and at least one of C". The term "set" does not necessarily exclude the empty set. The term "non-empty set" can be used to indicate the exclusion of the empty set. The term "subset" does not necessarily require a proper subset. In other words, a first subset of a first set can be coextensive (equal) with the first set.

[0059] In the drawings, the direction of the arrows (as indicated by the arrows) generally shows the information flow (such as data or instructions) that the illustration is concerned with. For example, when element A and element B exchange various information, but the information transmitted from element A to element B is relevant to the illustration, the arrow can point from element A to element B. This one-way arrow does not mean that no other information is transmitted from element B to element A. Additionally, for the information sent from element A to element B, element B can send a request for the information or receive an acknowledgement of the information from element A.

Claims

1. A radio frequency system, i.e., an RF system, comprising: a control printed circuit board, i.e., a control PCB, the control printed circuit board comprising a processor and a transmitter configured to generate an RF signal; as well as a waveguide antenna, the waveguide antenna being attached to the control printed circuit board, the waveguide antenna comprising an input channel, a curved transition chamber, a waveguide channel, and a radiator, the input channel being configured to receive the RF signal from the control printed circuit board along a first axis, the curved transition chamber being configured to receive the RF signal from the input channel and transmit the RF signal to the waveguide channel, the waveguide channel being configured to receive the RF signal from the curved transition chamber along a second axis orthogonal to the first axis and transmit the RF signal to the radiator, and the radiator being configured to transmit the RF signal to the outside of the RF system; Wherein, the curved transition chamber includes a short chamber having a width along a third axis orthogonal to both the first axis and the second axis, the width being greater than a width of the input channel along the third axis and greater than a width of the waveguide channel along the third axis.

2. The RF system according to claim 1, wherein: The waveguide antenna includes an upper waveguide portion and a lower waveguide portion each formed by a molding process.

3. The RF system of claim 2, wherein: The upper waveguide portion includes an upper chamber and the lower waveguide portion includes a lower chamber, such that when the upper waveguide portion and the lower waveguide portion are assembled together, the curved transition chamber is formed by the upper chamber and the lower chamber.

4. The RF system of claim 3, wherein: The upper chamber and the lower chamber are symmetrical along a plane formed by the second axis and the third axis.

5. The RF system of claim 2, wherein: The upper waveguide portion includes an upper waveguide part and the lower waveguide portion includes a lower waveguide part, such that when the upper waveguide portion and the lower waveguide portion are assembled together, the waveguide channel is formed by the upper waveguide part and the lower waveguide part.

6. The RF system of claim 5, wherein: The upper waveguide portion and the lower waveguide portion are symmetrical along a plane formed by the second axis and the third axis.

7. The RF system of claim 2, wherein: The upper waveguide portion and the lower waveguide portion are assembled together in the RF system without conductive paste and solder.

8. The RF system of claim 1, wherein: The short chamber includes a first protrusion extending from a first sidewall of the curved transition chamber along the third axis and a second protrusion extending from a second sidewall of the curved transition chamber opposite to the first sidewall.

9. The RF system of claim 8, wherein: The first protrusion and the second protrusion extend equal distances from the first side wall and the second side wall, respectively.

10. The RF system of claim 8, wherein: The first protrusion and the second protrusion extend different distances from the first side wall and the second side wall, respectively.

11. The RF system of claim 1, wherein: The short chamber includes only a protrusion extending from a first side wall of the curved transition chamber along the third axis, and a second side wall opposite to the first side wall does not include a protrusion.

12. The RF system of claim 1, wherein: The PCB and waveguide antenna are included in an automotive radar system configured to transmit and receive radar signals.

13. A radio frequency system, i.e., an RF system, comprising: a control printed circuit board, i.e., a control PCB, the control printed circuit board comprising a processor and a transmitter configured to generate an RF signal; as well as a waveguide antenna, the waveguide antenna being attached to the control printed circuit board, the waveguide antenna comprising an input channel, a curved transition chamber, a waveguide channel, and a radiator, the input channel being configured to receive the RF signal from the control printed circuit board along a first axis, the curved transition chamber being configured to receive the RF signal from the input channel and transmit the RF signal to the waveguide channel, the waveguide channel being configured to receive the RF signal from the curved transition chamber along a second axis orthogonal to the first axis and transmit the RF signal to the radiator, and the radiator being configured to transmit the RF signal to the outside of the RF system; in: The curved transition chamber includes a short chamber having a width along a third axis orthogonal to both the first axis and the second axis, the width being greater than a width of the input channel along the third axis and greater than a width of the waveguide channel along the third axis; The waveguide antenna includes an upper waveguide portion and a lower waveguide portion both formed by a molding process; The upper waveguide portion includes an upper chamber, and the lower waveguide portion includes a lower chamber, such that when the upper waveguide portion and the lower waveguide portion are assembled together, the curved transition chamber is formed by the upper chamber and the lower chamber; The upper waveguide portion comprises an upper waveguide part, and the lower waveguide portion comprises a lower waveguide part, such that when the upper waveguide portion and the lower waveguide portion are assembled together, the waveguide channel is formed by the upper waveguide part and the lower waveguide part; and The upper waveguide portion and the lower waveguide portion are assembled together in the RF system without conductive paste and solder.

14. The RF system of claim 13, wherein: The short chamber includes a protrusion extending from a sidewall of the curved transition chamber along the third axis.

15. The RF system of claim 13, wherein: The short chamber includes a first protrusion extending from a first side wall of the curved transition chamber along the third axis and a second protrusion extending from a second side wall of the curved transition chamber opposite to the first side wall, wherein the first protrusion and the second protrusion extend equal distances from the first side wall and the second side wall, respectively.

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