Microwave electronic devices comprising a metal enclosure
View Patent ↗The present invention relates to a microwave electronic device ( 1 ) comprising a metal enclosure ( 2 ) having a bottom ( 21 ) and a lid ( 23 ) and containing an electronic circuit board ( 3 ) disposed substantially parallel to said bottom and to said lid, said circuit board having: conductive bottom and top grounding layers ( 41, 42 ) respectively disposed on bottom and top faces ( 31, 32 ) of the circuit board, and perforations ( 7 a ) transverse to said faces of the circuit board and delimited by conductive walls ( 71 ) for electrically interconnecting said layers ( 41, 42 ). At least some of said walls ( 71 ) are electrically connected to the lid of the enclosure by conductive grounding members ( 8 a ). Each conductive member ( 8 a ) has a metal blade covered with a material ( 13, 13 ′) for absorbing microwaves.
1. A microwave electronic device ( 1 ) comprising a metal enclosure ( 2 ) having a bottom ( 21 ) and a lid ( 23 ) and containing an electronic circuit board ( 3 ) disposed substantially parallel to said bottom and to said lid, said circuit board having:
conductive bottom and top grounding layers ( 41 , 42 ) respectively disposed on bottom and top faces ( 31 , 32 ) of the circuit board, and
perforations ( 7 , 7 a ) transverse to said faces of the circuit board and delimited by conductive walls ( 71 ) for electrically interconnecting said bottom and top grounding layers ( 41 , 42 ), at least some of said walls ( 71 ) being electrically connected to the lid of the enclosure by conductive grounding members ( 8 , 8 a , 8 b ), which device is characterized in that each conductive member ( 8 a ) has a metal blade ( 11 , 11 ′) disposed between said lid and said top layer in a blade plane (P 1 ) perpendicular to said faces ( 31 , 32 ) and covered at least in part with a material ( 13 , 13 ′) for absorbing microwaves at frequencies less than or equal to a maximum operating frequency of said device.
2. A microwave electronic device ( 1 ) according to claim 1 , characterized in that each conductive member ( 8 a ) has two metal blades ( 11 , 11 ′) disposed in the same blade plane (P 1 ).
3. A microwave electronic device ( 1 ) according to claim 2 , characterized in that the respective blade planes (P 1 , P 2 ) of two adjacent needles ( 8 a , 8 b ) are substantially perpendicular.
4. A microwave electronic device ( 1 ) according to claim 1 , characterized in that said grounding members ( 8 , 8 a , 8 b ) are disposed so that the distance between the centers of two adjacent members ( 8 a , 8 b ) is less than the associated half-wavelength at said maximum frequency.
5. A microwave electronic device ( 1 ) according to claim 1 , characterized in that the top grounding layer ( 42 ) is formed of a plurality of substantially square metal members ( 5 , 5 a ) each having one of said perforations ( 7 a , 7 a ) at its center and receiving an associated grounding member ( 8 , 8 a , 8 b ).
6. A microwave electronic device ( 1 ) according to claim 1 , characterized in that each grounding member ( 8 , 8 a , 8 b ) has a portion in the form of a metal needle ( 8 a ) perpendicular to said faces ( 31 , 32 ) and having a cylindrical top part ( 82 ) and a frustoconical bottom part ( 83 ) extended by said associated perforation ( 7 a ) and in contact with said top grounding layer ( 42 ).
7. A microwave electronic device ( 1 ) according to claim 6 , characterized in that each of said needles ( 8 , 8 a , 8 b ) is centered on a respective square member ( 5 , 5 a ) and said top part ( 82 ) has a diameter between the diameter of the associated perforation ( 7 a ) and the side length of the associated square ( 5 a ).
8. A microwave electronic device ( 1 ) according to, claim 1 characterized in that the lid ( 23 ) has cavities ( 10 ) in its bottom face ( 230 ) each of which is coupled to a grounding member ( 8 a ) via a metal spring ( 9 ) disposed transversely to said bottom face of the lid.
9. An opto-electronic module incorporating a microwave electronic device according to claim 1 .