Patent ID: 7154441

Claim:
A device for transmitting or emitting high-frequency waves with: a microstrip line ( 10 ) provided with one end ( 10 ′) in a substrate ( 11 ) for transmitting high-frequency useful signals; a first ground surface ( 12 ) and a second ground surface ( 13 ), which are provided on opposite sides of the microstrip line ( 10 ), for forming a TEM waveguide assembly; an opening ( 14 ) in the first ground surface ( 12 ) located at a predefined distance (d) from the end of the microstrip line ( 10 ′) for decoupling a high-frequency signal; a feedthrough device ( 15 ) for conductively connecting the first ground surface ( 12 ) with the second ground surface ( 13 ) on the lateral periphery of the microstrip line ( 10 ); and a planar coupling device ( 16 ) for receiving and transmitting or emitting the high-frequency useful signal; whereby the feedthrough device ( 15 ) is configured in such a way that at a given frequency (f) it prevents the propagation of waveguide modes and the excitation of waveguide mode resonance in the useful frequency band (F), wherein the following relationship exists between the width (B) between diametrically opposed feedthrough devices ( 15 ) in the region of the coupling opening ( 14 ) and the length (L) of the feedthrough device in the region of the coupling opening ( 14 ): L < 1 ( 2 · f res · ɛ r c 0 ) 2 - ( 1 B ) 2 , whereby C 0 stands for the speed of light in a vacuum, ε r stands for the dielectric permittivity of the substrate ( 11 ), and f res stands for a resonant frequency (f res ) of an excitable waveguide mode which is provided above a useful signal frequency band (F).