Patent Application
20190165479
Automotive applications are requiring increased use of RF/microwave frequency bands, from low RF signals through millimeter-wave frequencies at 77 GigaHertz (GHz). As these high-frequency signals become more integral parts of the worldwide driving experience, effective test solutions become more critical for designers developing new automotive RF/microwave circuits, as well as production facilities seeking efficient methods for verifying the performance of these added circuits. While lower-frequency testers are in abundance, and automotive applications employ a wide range of wireless frequencies—including remote keyless entry (RKE) systems at 433 and 868 MHz—a growing concern in automotive markets is for the accurate and cost-effective testing of 77 GHz automotive radar systems. This interest stems from the fact that historically, measurement equipment at such high frequencies has neither been commonplace nor cost-effective.
A number of different automotive radar-based safety applications make use of frequencies from 76 to 77 GHz, for adaptive cruise control (ACC), blind-spot detection (BSD), emergency braking, forward collision warning (FCW), cross-traffic alert (CTA), lane change assist (LCA), and rear collision protection (RCP). For example, in a collision warning system, an automotive radar sensor can detect and track objects within the range of the transmitted and returned radar signals, automatically adjusting a vehicle's speed and distance in accordance with the detected targets. Different systems can provide a warning of a potential collision ahead and also initiate procedures leading to emergency braking as required.
The accompanying drawings, which are incorporated in and form a part of the Detailed Description, illustrate various embodiments of the subject matter and, together with the Detailed Description, serve to explain principles of the subject matter discussed below. Unless specifically noted, the drawings referred to in this Brief Description of Drawings should be understood as not being drawn to scale. Herein, like items are labeled with like item numbers.
The following Detailed Description is merely provided by way of example and not of limitation. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding background or in the following Detailed Description.
Reference will now be made in detail to various embodiments of the subject matter, examples of which are illustrated in the accompanying drawings. While various embodiments are discussed herein, it will be understood that they are not intended to limit to these embodiments. On the contrary, the presented embodiments are intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope the various embodiments as defined by the appended claims. Furthermore, in this Detailed Description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present subject matter. However, embodiments may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the described embodiments.
Some portions of the detailed descriptions which follow are presented in terms of procedures, logic blocks, processing and other symbolic representations of operations on data within an electrical device. These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. In the present application, a procedure, logic block, process, or the like, is conceived to be one or more self-consistent procedures or instructions leading to a desired result. The procedures are those requiring physical manipulations of physical quantities. Usually, although not necessarily, these quantities take the form of high frequency (e.g., millimeter or microwave) signals capable of being transmitted and received by an electronic device and/or electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in an electrical device.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the description of embodiments, discussions utilizing terms such as “interfacing,” “connecting,” “testing,” “receiving,” “introducing,” or the like, refer to the actions and processes of an electronic device such as an electrical device.
As used herein, a blind mate connector is differentiated from other types of connectors by the mating action that happens via a sliding or snapping action which can be accomplished without wrenches or other tools. They have self-aligning features which allows a small misalignment when mating.
As used herein, a choke flange is used in a choke connection, which is formed by mating one choke flange and one cover (or gasket/cover) flange or by mating one choke flange to another choke flange. The central region of the choke flange face is very slightly recessed so that it does not touch the face of the cover flange, but is separated from it by a narrow gap. The recessed region is bounded by a deep choke trench (or ditch or groove) cut into the face of the flange.
It is be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. It is appreciated that, in the following description, numerous specific details are set forth to provide a thorough understanding of the examples. However, it is appreciated that the examples may be practiced without limitation to these specific details. In other instances, well-known methods and structures may not be described in detail to avoid unnecessarily obscuring the description of the examples. Also, the examples may be used in combination with each other.
In recent years, radar capability has been added to motor vehicles, such as for adaptive cruise control (ACC) and forward collision warning (FCW). The radar frequency is typically in the 60 GigaHertz (GHz) to 90 GHz range, most commonly in the 71 GHz to 86 GHz region. The corresponding range in terms of wavelength is 5.0 millimeters (mm) to 3.33 mm and the corresponding region in terms of wavelength is 4.22 mm to 3.49 mm.
Testing of chipsets for automotive use has been relatively simple with only one or two radar inputs. However, more recently, additional radar inputs have been provided to motor vehicles, such as blind spot detection (BSD), rear collision protection (RCP), lane change assist (LCA), and cross traffic alert (CTA). While some of the radar inputs cover only front or rear, and thus only need one radar detector, others, such as BSD, CTA, and LCA, require two (one per side). It will be appreciated that such radar detection schemes can require six, or eight, or even more radar detectors.
Testing a chipset for one or two radar inputs does not impose much of a requirement for space for the radar waveguide connectors to the chipset. However, with an increasing number of radar inputs, there is simply not enough room for the presently-used UG-387/U flange, which is employed with WR12 waveguides, which are capable of transmitting millimeter waves in the region of 60 to 90 GHz.
In accordance with principles disclosed herein, a blind mate waveguide flange is provided.
The choke flange 204 avoids having to screw the waveguide flange to another waveguide flange, since screws to attach the waveguide to the chipset cannot work at such a density of waveguide flanges. The choke flange 204 also avoids the need for perfect alignment and thereby relaxation of tolerances.
As better seen in
The waveguide connection interface 230 further comprises a compression fitting 232 for connecting the blind mate waveguide flange 200 to the waveguide 240. An example of a suitable compression fitting 232 includes a nut 234 threadably secured to the opposite end having the second opening 224 at threaded surface 226, and including a ferrule 236 surrounding the waveguide 240 near its attachment to the waveguide connection interface 230.
As indicated above, the first shape of the first opening 206 may be rectangular, while the second shape of the second opening 224 may be oval, such that the waveguide transition section provides a rectangular-to-oval transition. The second opening 224 may be oval to accommodate an oval cross-section of the waveguide 240. In some embodiments, the waveguide 240 may be of a non-corrugated oval cross-section and is easily bendable so that it can be hand-formed on-site. It should be appreciated that waveguides having an oval cross-section are more easily bendable than waveguides having a rectangular or square cross-section, as the latter are more likely to kink or deform, impacting the ability of the waveguide to transmit signals. Moreover, it should be appreciated that waveguide 240 can be manufactured using a variety of materials, such as and without limitation: aluminum, copper, metal-plated plastic, etc.
In accordance with various embodiments, there are openings or holes 214 through the surface 202. It will be appreciated that these openings 214 are for providing interoperability with other components, such as a waveguide fixture or a waveguide fixture connector. Thus, the surface 202 is for interfacing with the surface of an element of the waveguide fixture or the waveguide fixture connector. In some embodiments, at least one opening 214 is threaded for receiving a screw. It should be appreciated that openings 214 are optional. In this connection, the surface of the element of the probe card holder may also comprise a choke flange. Further, if the need arises, the blind mate waveguide flange 200 may be mated to an RR12 flange or a UG-387/U flange. In this connection, it should be noted that the RR12 flange and the UG-387/U flange are each about 1 inch in diameter. For comparison, the blind mate waveguide flange 200 is about 0.25 inch by 0.25 inch.
While the configuration of the blind mate waveguide flange 200 may be suitable for a wide variety of millimeter-wave applications, it will be appreciated that the waveguide 240 and waveguide transition section 220 are particularly appropriate for transmitting millimeter-wave energy at 60 GHz to 100 GHz, and in some embodiments, at 76 GHz to 77 GHz.
In some embodiments, the blind mate waveguide flange 200 further comprises an anti-rotational external shape to provide alignment with a receiving mount. For example, there may be at least one alignment pin 216 for preventing rotation of the blind mate waveguide flange 200 within a probe card holder or a probe card holder connector. The alignment pin(s) 216 are visible in
As part of test apparatus to test automotive radar receivers on a chipset, a plurality of the blind mate choke flanges may be mounted on either or both of a waveguide fixture and a probe card holder, which, when matingly engaged, serve as a point of connection between a test head of the apparatus and the chipset. The test head is configured to provide source, receive, measure, and signal processing capability. The probe card is configured to communicate with the radar chipset. The waveguide fixture and the probe card holder are configured to be brought together into mating contact to convey signals between the test head and the chipset for testing.
In accordance with principles disclosed herein, blind mate waveguide flange 200 may be used for connecting a waveguide 240 to a probe card holder.
Probe card holder connector 300, in accordance with various embodiments, operates as an interface for connecting blind mate waveguide flange 200 to a probe card holder. Probe card holder connector 300 includes an opening 302 for receiving choke flange 204 of blind mate waveguide flange 200. In one embodiment, when blind mate waveguide flange 200 is inserted into opening 302, surface 202 contacts the facing surface of probe card holder connector 300 and peripheral region 210 of blind mate waveguide flange 200 is substantially flush with surface 304 of probe card holder connector 300. It should be appreciated that peripheral region 210 and surface 304 need not be perfectly flush, so long as peripheral region 210 is available for surface contact with an opposing waveguide interface.
In some embodiments, probe card holder connector 300 may optionally include openings 306 for interfacing with pins 216 and/or pins for interfacing with openings 214 for aligning first opening 206 relative to probe card holder connector 300. In some embodiments, probe card holder connector 300 includes opening 308 for receiving screw 310 that interfaces with a threaded opening 214 of blind mate waveguide flange 200. In some embodiments, probe card holder connector 300 includes a groove 312 for receiving gasket 314 (e.g., a rubber gasket or O-ring). In some embodiments, probe card holder connector 300 includes opening 316 and pins 318 for interfacing with a probe card holder.
In another embodiment, the element 414 may have the choke flange and the flanges 200 being devoid of the choke flange 204.
In yet another embodiment, both the blind mate waveguide flange 200 and the element 414 have the choke flange 204.
For ease of alignment, a blind mate waveguide flange 200 may be connected to a waveguide fixture connector 300 for connection to waveguide fixture 406. Such a waveguide fixture connector 300 is shown for some of the blind mate waveguide flanges 200, with one of the receiving mounts shown in cross-section. The probe card holder 408 has a plurality of the elements 414. Elements 414 are configured to support the blind mate waveguide flange 200.
A method of using the blind mate waveguide flange 200 includes interfacing the choke flange 204 of the blind mate waveguide flange with the waveguide probe interface (probe card holder) 408. The choke flange 204 comprises a choke groove 208 separating a peripheral region 210 from an inner region 212 of the choke flange 204. The inner region 212 is recessed relative to the peripheral region 210 to provide an air gap upon mating with another mating surface. The first opening 206 has a first shape, e.g., rectangular.
The method of using the blind mate waveguide flange 200 further includes interfacing the waveguide connection interface 230 with one end of a waveguide 240. The waveguide connection interface 230 comprises a second opening at an opposite end of the waveguide transition section 220. The second opening has a second shape, e.g., oval, such that the waveguide transition section 220 provides a transition from the first shape to the second shape.
The method further includes connecting the waveguide 240 to a source of microwave energy in the test head assembly 402 and connecting another end of the waveguide 240 to the chipset 410 for testing.
The method further includes introducing microwave energy through the waveguide 240 to the first opening 206 of the blind mate waveguide flange 200. The microwave energy may be within a range of 60 gigahertz to 100 gigahertz.
It is appreciated that, in the foregoing description, numerous specific details are set forth to provide a thorough understanding of the examples. However, it is appreciated that the examples may be practiced without limitation to these specific details. In other instances, well-known methods and structures may not be described in detail to avoid unnecessarily obscuring the description of the examples. Also, the examples may be used in combination with each other.
While a limited number of examples have been disclosed, it should be understood that there are numerous modifications and variations therefrom. Similar or equal elements in the Figures may be indicated using the same numeral.
