Radio frequency device with optimised radiation pattern for gesture sensing in a motor vehicle

A device (20;

• 900) for transmitting and/or receiving radio-frequency signals, which is intended to be integrated into a gesture-detecting system in a motor vehicle, and which comprises:
• a printed circuit board (930);
• at least one first radio-frequency antenna (310;
• 510;
• 610;
• 910), integrated into the printed circuit board and dedicated to transmitting and/or receiving a radio-frequency signal propagating through a first detection zone (Z1);
• and
• at least one second radio-frequency antenna (720;
• 920), integrated into the printed circuit board and dedicated to transmitting and/or receiving a radio-frequency signal propagating through a second detection zone (Z2) distinct from the first detection zone;
• characterized in that:
• the at least one first radio-frequency antenna (310;
• 510;
• 610;
• 910) consists of at least one patch antenna, called the T-antenna, comprising superposed a first metal excitation surface (311;
• 511;
• 611) and a first ground plane (313;
• 513;
• 613), at least one of the first ground plane and the first metal excitation surface having a T-shaped region (313A;
• 511B;
• 613A), so that the radiation pattern of the T-antenna has two high-radiation side lobes (341) separated by a low-radiation central zone (342);
• and
• the at least one second radio-frequency antenna (720;
• 920) consists of at least one patch antenna, called the rectangular antenna, comprising superposed a second metal excitation surface (721) and a second ground plane (723), the second metal excitation surface comprising a rectangular region (721A) having a general rectangle shape and configured so that the radiation pattern of the rectangular antenna has two high-radiation side lobes (741) separated by a low-radiation central zone (742).