Antenna device and antenna system

An antenna system comprising

• a first antenna device;
• and
• a second antenna device,
• wherein
• the first antenna device and the second antenna device individually comprise:
• a node;
• a first radiating element in a first plane and coupled with the node, the first radiating element being configured to radiate a radio wave in response to a radio frequency (RF) signal being fed to the first radiating element by way of the node;
• a second radiating element in a second plane different from the first plane and coupled with the node, the second radiating element being configured to radiate a radio wave in response to the RF signal being fed to the second radiating element by way of the node;
• and
• a non-reflective plate in a third plane different from the first plane and the second plane,
• wherein
• the antenna device is configured such that the RF signal is fed to the first radiating element and the second radiating element with a difference of phase between the first radiating element and the second radiating element, and
• the first radiating element is between the second radiating element and the non-reflective plate,
• the first antenna device and the second antenna device are configured to be arranged such that the non-reflective plate of the first antenna device is between the first radiating element of the first antenna device and the second antenna device, and
• the second antenna device is configured to radiate one or more radio waves toward the non-reflective plate.