Abstract: The disclosure relates to suppressing surface waves in a communication device for a wireless communication system. The communication device includes a dielectric layer extending along a plane between a chassis and a glass layer, an antenna element configured to emit a radio wave, and a retroreflective structure extending inside the dielectric layer and being located adjacent to the antenna element, and where the retroreflective structure is configured to reflect the radio wave in an angle non-parallel to the plane. The retroreflective structure hence prevents parasitic channeling of the antenna energy into surface waves in and behind the glass layer and directs the radiation into the desired direction.

Abstract: The invention relates to a method of dividing the power of an input electromagnetic signal into two equal-power signals with a relative phase difference of 180° between them and an equal propagation delay. The inventive method makes use of a photonic crystal coupler comprising two parallel guides which are disposed close to one another and which are based on coupled cavities. The method consists in exciting the odd mode of the coupler which, owing to the symmetry thereof, ensures that the field maxima coincide in one guide with the minima in the adjacent guide, thereby producing a relative phase difference of 180°. The two output signals are obtained through the spatial separation of the guides forming the coupler, making use of the property possessed by guides in photonic crystals for high transmission efficiency through very tight curves. In this way, the size of the structure can be reduced considerably. The inventive method can be used for both two-dimensional and three-dimensional photonic crystals.

Abstract: The invention relates to a method of dividing the power of an input electromagnetic signal into two equal-power signals with a relative phase difference of 180° between them and an equal propagation delay. The inventive method makes use of a photonic crystal coupler comprising two parallel guides which are disposed close to one another and which are based on coupled cavities. The method consists in exciting the odd mode of the coupler which, owing to the symmetry thereof, ensures that the field maxima coincide in one guide with the minima in the adjacent guide, thereby producing a relative phase difference of 180°. The two output signals are obtained through the spatial separation of the guides forming the coupler, making use of the property possessed by guides in photonic crystals for high transmission efficiency through very tight curves. In this way, the size of the structure can be reduced considerably. The inventive method can be used for both two-dimensional and three-dimensional photonic crystals.