Device to reflect and transmit electromagnetic wave and antenna device

An antenna device comprising:

• a device that includes a dielectric for reflecting and transmitting an electromagnetic wave;
• and
• an antenna that sends an associated wave received from the device, wherein
• a front and a back of the dielectric of the device are defined by a first surface and a second surface and the first or second surface forms a half mirror,
• the first surface has a height that changes in spiral as leaving from the second surface,
• the second surface has a height that changes in spiral as leaving from the first surface, and
• an electromagnetic wave reflected by the first surface, which is an electromagnetic wave having first orbital angular momentum, and an electromagnetic wave transmitted from the second surface to the first surface, which is an electromagnetic wave having second orbital angular momentum, are multiplexed to generate the associated wave.

An antenna device comprising:

• a first device that includes a first dielectric for reflecting and transmitting an electromagnetic wave;
• a second device that includes a second dielectric for reflecting and transmitting an electromagnetic wave;
• and
• an antenna that sends a second associated wave received from the second device, wherein
• a front and a back of the first dielectric of the first device are defined by a first surface and a second surface and the first or second surface forms a half mirror,
• the first surface has a height that changes in spiral as leaving from the second surface,
• the second surface has a height that changes in spiral as leaving from the first surface,
• an electromagnetic wave reflected by the first surface, which is an electromagnetic wave having first orbital angular momentum, and an electromagnetic wave transmitted from the second surface to the first surface, which is an electromagnetic wave having second orbital angular momentum, are multiplexed to generate a first associated wave,
• a front and a back of the second dielectric of the second device are defined by a third surface and a fourth surface,
• the third surface has a height that changes in spiral as leaving from the fourth surface,
• the fourth surface has a height that changes in spiral as leaving from the third surface, and
• an electromagnetic wave reflected by the third surface, which is an electromagnetic wave having third orbital angular momentum, and an electromagnetic wave outputted from the third surface when the first associated wave is transmitted from the fourth surface to the third surface are multiplexed to generate the second associated wave.

A communication system comprising:

• a sending device that includes a multiplexing device including a first dielectric for reflecting and transmitting an electromagnetic wave and a sending and receiving antenna to send an associated wave;
• and
• a receiving device that includes a separating device including a receiving antenna to receive the associated wave and a second dielectric for reflecting and transmitting an electromagnetic wave, wherein
• a front and a back of the first dielectric of the multiplexing device are defined by a first surfaces and a second surface and the first or second surface forms a half mirror,
• the first surface has a height that changes in spiral as leaving from the second surface,
• the second surface has a height that changes in spiral as leaving from the first surface,
• an electromagnetic wave reflected by the first surface, which is an electromagnetic wave having first orbital angular momentum, and an electromagnetic wave transmitted from the second surface to the first surface, which is an electromagnetic wave having second orbital angular momentum, are multiplexed to generate the associated wave,
• a front and a back of the second dielectric of the separating device are defined by a third surface and a fourth surface,
• the third surface has a height that changes in spiral as leaving from the fourth surface,
• the fourth surface has a height that changes in spiral as leaving from the third surface, and
• the separating device obtains an electromagnetic wave incident on the first surface from an electromagnetic wave reflected by the third surface among the associated wave and obtains an electromagnetic wave incident on the second surface from an electromagnetic wave transmitted from the third surface to the fourth surface among the associated wave.