Patent Application
20150137912
This application claims priority to pending European Application No. 13193874.8 filed on Nov. 21, 2013, which is incorporated by reference in its entirety.
1. Field of the Invention
The invention relates to an RF connector assembly which may be used for millimeter waves and which can be mounted to a printed circuit board. A further aspect of the invention is a transmission line, which may be used to connect an RF connector to a printed circuit board. The transmission line is based on a band conductor.
2. Description of Relevant Art
A RF connector assembly is disclosed in U.S. Pat. No. 6,607,400 B1. A connector is mounted into a cutout of a printed circuit board. The electrical contact is established by soldering pads to a ground plane and to a signal line. Due to their design, such connectors are only suitable for frequencies up to order of magnitude of 1 GHz.
A millimeter wave connector for interconnecting a microstrip circuit and an external circuit is disclosed in U.S. Pat. No. 4,669,805. The connector is held in a housing, which also contains a microstrip substrate to be connected to the connector. During assembly, the flexible center conductor of the connector has to be bent to adapt to the microstrip circuit. Bending of the center conductor may cause asymmetries, which degrade the electrical characteristics of the connector.
U.S. Pat. No. 5,797,765 discloses a coaxial connector for mounting on a circuit substrate. The connector is soldered under a right angle to the surface of a substrate. For contacting the center conductor, a bond wire is used. Therefore, assembly of this connector requires complex special machines for bonding.
The embodiments are based on the object of providing a millimeter wave connector, which can be mounted to a printed circuit board or any other microstrip substrate without requiring complex and expensive mounting tools. Furthermore, it is desirable to have a connector, which can be mounted to the edge or any other location of a printed circuit board and which may be mounted essentially parallel or under any other angle to the printed circuit board. Another problem to be solved is to provide a transmission line with a band conductor, which may be used to connect such a connector to a printed circuit board.
In an embodiment, a transmission line is held by a housing and preferably integrated into the housing. There is an outer conductor which may be formed by the housing, or which may be a metal tube, preferably a tube having a rectangular, squared, or round cross-section. Within the outer conductor, an inner conductor is provided. It preferably comprises metal band and preferably has a rectangular cross-section. The outer conductor has a straight form, but may also be bent or curved to any other form. The inner conductor is held by a plurality of holding pins at a specific position, preferably centered within the outer conductor. The inner conductor preferably follows the bending or curve of the outer conductor. The holding pins are held by holes in the outer conductor and penetrate the inner conductor through holes in the inner conductor. The holes may be round or elongated holes, which may tolerate some movement of the inner conductor. It is preferred, if the holding pins comprise a first pin section and a second pin section. Preferably, each pin section has a pin head and a pin shaft. A first pin shaft and a second pin shaft preferably are formed such that they can be connected together. They may have a plug (male) component and a socket (female) component. Preferably, at the center of the pin a gap is formed which interfaces with a hole of the inner conductor and holes the inner conductor at a predetermined position. Due to the holding pins, the inner conductor follows the shape or curve of the outer conductor. It is perfectly centered within the outer conductor. Therefore, the presiding transmission line has excellent properties in the millimeter wave range (like frequencies up to 110 GHz).
The inner conductor and the outer conductor preferably are made of a metal, like aluminum, brass, copper, or any other suitable material, or any alloy thereof. It is further preferred to have the inner conductor of a material, which has elastic or spring-elastic properties. It is further preferred, if at least one of the outer conductor and inner conductor have a coating of a high-conductive and low-corrosive material or metal, like silver or gold.
Preferably, the holding pins are made of an insulating material, like plastic material. Most preferably, they are manufactured by injection molding. It is further preferred, if the holding pins are directly injection molded to the inner connector.
In another embodiment, a millimeter wave connector for printed circuit boards comprises a housing, an RF connector, and a transmission line for connecting the RF connector preferably to a printed circuit board.
The transmission line preferably has a first end with a printed circuit board contact. This printed circuit board contact preferably is a tapered section of the inner conductor, which may be pressed against a strip line of a printed circuit board. The transmission line may have a second end for contacting the RF connector for connecting the center conductor of the RF connector. Preferably, it is mounted in such a spatial relation to the RF connector that it asserts a light force due to its spring-elastic property against the center conductor of the RF connector, therefore achieving a proper electrical contact. It is preferred, if the RF connector is a standard RF connector. It is further preferred to hold a flange type RF connector within the housing. Although the transmission line is disclosed herein with a preferred embodiment having means for connecting to a printed circuit board and a RF connector, the transmission line is not limited to this application. It may be a general transmission line being suitable for any purpose a transmission line can be used. It is further preferred, if the transmission line is a semi rigid transmission line. If the outer conductor is bent, the inner conductor of the following this bending and therefore maintain the good transmission line properties.
In a further embodiment, a connector assembly has a housing which holds a transmission line and two coaxial line connectors. Each end of the transmission line is connected to one of the coaxial line connectors. The coaxial line connectors may be flanges holding a coaxial line. It is further preferred, if at least one of the coaxial line connectors holds a center conductor having a slotted end for contacting the inner conductor. The inner conductor may be slidable in the slot to compensate for length changes of the center conductors which may be caused by thermal expansion. The inner conductor may be straight, but preferably, the inner conductor is arc shaped and the two coaxial line connectors are mounted under an angle to the housing, whereas the angle preferably is in the range between 60° and 120°, most preferably 90°. Such a connector assembly may be in the form of an elbow.
In the following, the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment and with reference to the drawings.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
In
The transmission line has a first end with a printed circuit board contact 211. This is preferably a tapered end, which is preferably spring-loaded due to the spring properties of the transmission line to press against the strip line 410 of the printed circuit board 400 and establish an electrical contact.
Furthermore, the transmission line has a second end preferably having a connector contact 212, which is preferably designed to press by spring forces against the inner conductor 310 of the RF connector 300. Furthermore, it is preferred to have a two part connector comprising a connector housing 330 and a connector center part 340 which are connected by a thread 350. When the connector center part 340 is rotated against the connector housing 330 to lock the connector, the outer conductor 320 of the RF connector together with the inner conductor 310 of the RF connector are moved against the outer conductor 220 of the transmission line and the inner conductor 210 of the transmission line to establish a good electrical contact. In an alternate embodiment, a press fit of the RF connector 300 within housing 100, to press the outer conductor 320 of the RF connector 300 against the outer conductor 220 of the transmission line may be provided. At the printed circuit board side, the outer conductor 220 of the transmission line 200 is pressed against a ground plane 420 of the printed circuit board, to establish an electrical contact.
The section of the housing 100 shown herein preferably is a half housing, which is complemented by a second half housing, preferably approximately symmetrical to the first one. The housing sections may be connected by screws through clamping holes 140.
In general, the transmission line may be used alone without the RF connector 300 and the printed circuit board contact 211.
In
It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to provide a millimeter wave connector and a band conductor. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 13193874.8 | Nov 2013 | EP | regional |
