Sensor for controlling access to a motor vehicle, having an electrode surrounded by an antenna

A device for a vehicle access control system, intended to be housed on board a motor vehicle for carrying out an approach detection of a user as well as recognition of said user, and comprising:

• a main electrode, intended to form a capacitor with a user for carrying out a capacitive-type approach detection;
• and
• a transmitting and receiving antenna which is formed by a coil comprising a plurality of turns which all have a similar shape and is configured to transmit and receive a radiofrequency signal in order to identify a user;
• wherein the main electrode is surrounded by one turn of the coil, referred to as the guard turn;
• the guard turn comprising:
• a first portion which delimits a region inside of which the main electrode is located,
• a second portion which is offset relative to the main electrode, and
• at least one notch which extends along an edge of the main electrode and connects the first portion and the second portion together, each notch comprising two sections which are parallel to one another and are connected together by a portion of the turn located at the bottom of the notch,
• and the other turns of the coil each have a shape substantially similar to that of the guard turn, each with two portions separated in pairs by at least one notch;
• a first assembly, comprising said main electrode, forming a first main electrode, and a first guard electrode superimposed on the first main electrode along an axis orthogonal to the plane of the printed circuit;
• a second assembly, comprising a second electrode, called the second main electrode, as well as a second guard electrode superimposed on the second main electrode along an axis orthogonal to the plane of the printed circuit;
• and wherein:
• the first main electrode and the second guard electrode are arranged coplanar on the same top layer of the printed circuit;
• the second main electrode and the first guard electrode are arranged coplanar on the same lower layer of the printed circuit, distinct from said upper layer of the printed circuit;
• the guard turn surrounds the first main electrode and the second guard electrode, with the at least one notch which extends between the first main electrode and the second guard electrode;
• and
• the transmitting and receiving antenna coil further comprises a second turn, called a second guard turn, surrounding the second main electrode and the first guard electrode, with at least one notch of said second guard turn which extends between the second main electrode and the first guard electrode.

A device for a vehicle access control system, intended to be housed on board a motor vehicle for carrying out an approach detection of a user as well as recognition of said user, and comprising:

• a main electrode, intended to form a capacitor with a user for carrying out a capacitive-type approach detection;
• and
• a transmitting and receiving antenna which is formed by a coil comprising a plurality of turns which all have a similar shape and is configured to transmit and receive a radiofrequency signal in order to identify a user;
• wherein the main electrode is surrounded by one turn of the coil, referred to as the guard turn;
• the guard turn comprising:
• a first portion which delimits a region inside of which the main electrode is located,
• a second portion which is offset relative to the main electrode, and
• at least one notch which extends along an edge of the main electrode and connects the first portion and the second portion together, each notch comprising two sections which are parallel to one another and are connected together by a portion of the turn located at the bottom of the notch,
• and the other turns of the coil each have a shape substantially similar to that of the guard turn, each with two portions separated in pairs by at least one notch;
• a first assembly, comprising said main electrode, forming a first main electrode, and a first guard electrode superimposed on the first main electrode along an axis orthogonal to the plane of the printed circuit;
• a second assembly, comprising a second electrode, called the second main electrode, as well as a second guard electrode superimposed on the second main electrode along an axis orthogonal to the plane of the printed circuit;
• and wherein:
• the first main electrode and the second main electrode are arranged coplanar on the same top layer of the printed circuit;
• the first guard electrode and the second guard electrode are arranged coplanar on the same lower layer of the printed circuit, distinct from said upper layer of the printed circuit;
• the guard turn surrounds the first main electrode and the second main electrode, with the at least one notch which extends between the first main electrode and the second main electrode;
• and
• the transmitting and receiving antenna coil further comprises a second turn, called a second guard turn, surrounding the first guard electrode and the second guard electrode, with at least one notch of said second guard turn which extends between the first guard electrode and the second guard electrode.