Conformal rf antenna array and integrated out-of-band eme rejection filter

A conformal antenna array for flush mounting on a curved surface, said conformal antenna array comprising:

• a metal backing sheet that provides a bottom ground plane, said metal backing sheet have a hole formed therein;
• first, second and third pairs of a metal sheet cladding a layer of dielectric material, said layer of dielectric material from said first pair being disposed over the metal backing sheet, said metal sheet from said second pair providing a top ground plane;
• wherein said metal backing sheet and said first, second and third pair of the metal sheet cladding the layer of dielectric material have a non-planar shape that conforms to the curved surface;
• an array of microstrip antenna elements patterned in the metal sheet of the third pair, said array configured to transmit and receive RF signals in an operating frequency band;
• a feed network comprising multiple levels of interconnected stripline power dividers/combiners patterned in the metal sheet of the first pair between the top and bottom ground planes that connect the plurality of antenna elements to a common feed node;
• an edge-coupled stripline bandpass filter (BPF) fabricated in the bottom metal sheet of the first pair between the top and bottom ground planes that connects the common feed node to an RF pin that extends through the hole in the metal backing sheet, said edge-coupled stripline BPF configured to pass RF energy in the operating frequency band and reject electromagnetic environment (EME) energy outside the operating frequency band;
• and
• a coaxial RF connector having an internal conductor that is connected to the RF pin and an external conductor that is connected to the metal backing sheet to bring in-band RF energy to and from the conformal antenna array.

A vehicle datalink comprising:

• a vehicle including a body having a curved surface;
• a radio positioned inside the vehicle body, said radio including a stack of planar circuit cards configured to transmit and receive RF signals in an operating frequency band;
• a first coaxial RF connector coupled to the radio;
• a conformal antenna board having a non-planar shape that conforms to the curved surface of the vehicle body, said antenna board comprising:
• a metal backing sheet that provides a bottom ground plane, said metal backing sheet have a hole formed therein;
• at least one pair of a metal sheet cladding a layer of dielectric material, a bottom layer of dielectric material being disposed over the metal backing sheet;
• an array of microstrip antenna elements patterned in a top metal sheet, said array configured to transmit and receive RF signals in an operating frequency band;
• a feed network comprising multiple levels of interconnected power dividers/combiners patterned in a bottom metal sheet to connect the plurality of antenna elements to a common feed node;
• and
• an out-of-band rejection filter fabricated in the bottom metal sheet that connects the common feed node to an RF pin that extends through the hole in the metal backing sheet, said out-of-band rejection filter configured to reject electromagnetic environment (EME) energy outside the operating frequency band;
• and
• a second coaxial RF connector having an internal conductor that is connected to the RF pin and an external conductor that is connected to the metal backing sheet and coupled to the first coaxial RF connector as a mated pair, said first and second coaxial RF connectors configures to bring in-band RF energy to and from the conformal antenna array,
• wherein said first and second coaxial RF connectors are configured to handle a specified maximum power level above a maximum in-band transmit power of the radio through the antenna array but less than a specified out-of-band EME power level.