Patent ID: 8164542

Claim:
Antenna using PBG (photonic band gap) material with a defect, comprising: a first PBG material ( 4 ) having at least one-dimensional periodicity and an outer face ( 20 ) that is radiant in transmission and/or in reception, at least one first periodicity defect of the PBG material forming a first resonant cavity ( 8 ) capable of creating at least one narrow passband within a stop band of the PBG material, the cavity having an upper wall formed by a lower face of the PBG material opposite the radiating outer face, and a lower wall facing the upper wall, and at least one excitation device ( 10 ; 70 ; 86 ; 94 ; 100 ; 112 ; 132 ; 152 ) capable of making the resonant cavity resonate, the device having a surface ( 26 ; 122 ) for injecting and/or receiving electromagnetic waves at a working frequency contained within the narrow passband, the surface being flush with the lower wall of the cavity, the injection and/or reception surface having at least a width or a length or a diameter greater than λ, where λ is the wavelength of the working frequency, and the distribution of the power of the electromagnetic waves over the injection and/or reception surface having a point where the power is maximum, that point being remote from the periphery of the surface, and the power decreasing continuously along a straight line running from that point to the periphery, irrespective of the direction of the straight line considered in the plane of that surface, wherein the excitation device comprises at least one flared electromagnetic waveguide ( 32 ; 52 , 54 ; 70 ; 86 ; 94 ; 100 ) equipped with a distal end, which opens inside the resonant cavity, and a proximal end capable of being connected to an electromagnetic wave generator and/or receiver ( 30 ), the surface area of the transverse cross-section of the distal end being strictly greater than the surface area of the transverse cross-section of the proximal end, and in which the distal end of the waveguide is flush with the lower wall in order to form said injection and/or reception surface.