EP-4226461-B1 - LAMINATED ASSEMBLY COMPRISING RADIO-FREQUENCY INTERFACE BOARD

Inventors

• YOUSEFBEIKI, Mohsen
• ADDACI, Rafik

Dates

Publication Date

20260513

Application Date

20210623

Claims (13)

1. Laminated assembly (100) comprising: - A first and a second dielectric panels (101, 102) laminated on opposing faces of a polymeric-based interlayer (110); each of the first and the second dielectric panels has an internal surface (101i, 102i); the internal surfaces are facing each other; - a first and a second conductive elements (121, 122); the first conductive element is disposed on the internal surface of the first dielectric panel; the two conductive elements are isolated from each other and - an RF interface board, having an inner (141) and an outer (142) part; the inner part is at least partially laminated with the first and the second dielectric panels by the polymeric based interlayer, the RF interface board comprising ∘ a dielectric support (150) having a first (151) and a second (152) surface; and ∘ at least a first (161) and a second (162) RF transmission strips disposed on the dielectric support; the first and the second RF transmission strips are electrically isolated from each other; wherein the first and the second surface of the inner part of the RF interface board are substantially flat and parallel to each other and the first RF transmission strip is electrically connected to the first conductive element at the inner part of the RF interface board and the second RF transmission strip is electrically connected to the second conductive element at the inner part of the RF interface board.
2. Laminated assembly (100) according to claim 1 wherein the second RF transmission strip of the RF interface board is on the first surface of the dielectric support.
3. Laminated assembly (100) according to claim 1 wherein the second RF transmission strip of the RF interface board is on the second surface of the dielectric support.
4. Laminated Assembly (100) according to any preceding claims wherein the RF interface board comprises a third RF transmission strip (13, 14) disposed on the dielectric support and isolated from the other RF transmission strips.
5. Laminated assembly according to any preceding claims wherein the second conductive element is disposed on the internal surface of the first dielectric panel; the second conductive element is electrically isolated from the first conductive element.
6. Laminated assembly according to any of claim 1 to 4 wherein the second conductive element is disposed on the internal surface of the second dielectric panel.
7. Laminated assembly according to claim 6 wherein the second RF transmission strip is on the second surface of the RF interface board.
8. Laminated assembly according to any preceding claims wherein the at least two conductive elements are coating systems comprising at least a conductive layer.
9. Laminated assembly according to any preceding claims wherein the polymeric-based interlayer is a COP or ionomer-based interlayer.
10. Laminated assembly according to any preceding claims wherein the first and/or the second dielectric panel is a PET-based panel.
11. Method for electrically connecting a laminated assembly according to any preceding claims wherein the method comprises a step of connecting the shield of a coaxial cable to the first RF transmission strip at the outer part of the dielectric support and the core of the coaxial cable to the second RF transmission strip at the outer part of the dielectric support.
12. Method for electrically connecting a laminated assembly according to claims 1 to 11 wherein the method comprises a step of connecting a commercially-available connector to the first RF transmission strip and to the second RF transmission strip of the dielectric support.
13. Use of a RF interface board for connecting a connector or soldering a cable to transmit and/or receive RF signal to the outside of a laminated assembly according to claim 1, wherein the first and the second RF transmission strips are configured to be connected to an RF connector or to an RF module at the outer part and are each configured to be connected to a different conductive element at the inner part.

Description

Technical Field The present invention relates to a laminated assembly connected with at least an Radio Frequency (RF) interface board. The invention is preferably used to feed an laminated assembly encompassing an antenna and especially a patch antenna. Thus, the invention concerns multiple domains where laminated assembly including at least one RF interface board is used. Background Art To emit an RF signal to and/or to receive an RF signal from an antenna a transmission line, for example a coaxial cable, needs to be connected between the antenna and the RF module. Sometimes, to avoid to connect directly the cable to the antenna, an RF connector is used. A connector has a standardized male/female terminal and the connector is soldered and/or screwed to the conductive parts of the antenna. In a second time, the cable is fixed to this terminal. Therefore, each application and/or antenna needs a specific connector to be soldered at the right place. Antennas can be classified as omnidirectional, radiating energy approximately equally in all directions, or directional, where energy radiates more along one direction than others. A "directional" antenna usually is intended to maximize its coupling to the electromagnetic field in the direction of the other station. Antennas can be made of conductive wire, for example for FM, AM signal. These wires can be placed in the space or printed on a dielectric support. Antennas can be more complex needing several conductive elements in relation to each other, for example a patch antenna. In the case of patch antenna, for example, the antenna comprises at least three elements, a patch, a feed line, and a ground plane. To achieve a set of specific performance criteria, specific spacing between the patch and/or the feed line and the ground plane is needed. Other types of conductive systems may need an isolated specific distance between two conductive elements. The document EP3289638 A1 discloses a connector between two conductive elements and a coaxial cable. This connector pinches the cable to electrically connect the cable and the two conductive elements and cannot be used inside a laminated structure because of its size and volume. The document EP3478497 A1 discloses the use of a flat and flexible connector to connect the inside of a laminated structure. This connector can only connect to one surface of a laminated structure. When several conductive elements on different surfaces need to be connected to the outside of the structure, each conductive element need its own interface. Thus, especially for an antenna application, a very customized connector is needed to feed the conductive elements present inside the laminated structure. Furthermore, the impedance matching of the antenna becomes more challenging due to subsequent parasitic capacitive and inductive loadings. The document US2006084285 A1 relates to a circuit carrier that can be laminated. The carrier comprises conductive elements that are isolated from each other. This document recites terminal contacts that cannot be re-routed through connections. The document US5219292 A relates to a printed circuit substrate interconnection is made between two printed circuit substrates. Summary of invention The present invention relates to a laminated assembly according to claim 1. Preferably, the RF interface board has substantially the same thickness along the whole surface. According to the present invention, on the outer part of the RF interface board a set of matching components, for example capacitors and inductors and/or their equivalent distributed-element circuits, can be connected to the RF transmission strips (between the place the coaxial cable or the RF connector is attached and the edge of the laminated assembly) in order to tune the impedance response of the laminated assembly. According to the present invention, on the outer part of the RF interface board the RF module partially or entirely can be directly connected to the RF transmission strips. The present invention also relates to a method for electrically connecting a laminated assembly according to the present invention, wherein the method comprises a step of connecting the shield of a coaxial cable to the first RF transmission strip at the outer part of the dielectric support and the core of the coaxial cable to the second RF transmission strip at the outer part of the dielectric support. Finally, the present invention relates to the use of a RF interface board for connecting a connector or soldering a cable to transmit and/or receive RF signal to the outside of a laminated assembly according to claim 1. It is noted that the invention relates to all possible combinations of features recited in the claims. The following description relates to building applications but it's understood that the invention may be applicable to others fields like automotive or transportation applications. Brief description of the drawings This and other aspects of the present in