Aperture coupled slot array antenna

An antenna, suitable for transmitting and receiving electromagnetic signals of wavelengths λ1 and λ2, said antenna comprising:

• a nonconductive substantially planar substrate having first and second surfaces bounded by a common peripheral edge, said peripheral edge enclosing an antenna axis orthogonal to said surfaces;
• a transmission line disposed on said first surface, said transmission line comprising a first end, a second end, and an inner edge extending between said first and second ends, at least a portion of said inner edge forming an arc of radius R centered on said antenna axis;
• and
• a conductive layer disposed on said second surface,
• said conductive layer comprising a first array of m slotted openings, each said first array slotted opening having a peripheral end located proximate said peripheral edge and an axial end located within a distance R of said antenna axis, each said first array slotted opening having a guided wave length of integer multiples λ 1 4 ,
• between said peripheral end and said axial end, at least one said first array slotted opening spatially separated from an adjacent said first array slotted opening by an angle of 2 ⁢ π m ;
• said conductive layer further comprising a second array of m slotted openings, each said second array slotted opening having a peripheral end located proximate said peripheral edge and an axial end located within a distance R of said antenna axis, each said second array slotted opening having a guided wave length of integer multiples of λ 2 4
• between said peripheral end and said axial end, at least one said second array slotted opening spatially separated from an adjacent said second array slotted opening by an angle of 2 ⁢ π m
• whereby, when an electromagnetic signal is fed into said transmission line via said first end, electromagnetic energy is sequentially coupled into respective said slotted openings such that a radiated signal having a wavelength of either or both λ1 and λ2 is transmitted from said slotted openings substantially in the direction of said antenna axis.

A planar antenna suitable for transmitting or receiving an electromagnetic signal, said antenna comprising:

• an array of m slotted openings disposed in a top surface of the planar antenna, said slotted openings for receiving or transmitting the electromagnetic signal, said array of slotted openings defining an antenna axis;
• and
• a transmission line for sequentially coupling the received or transmitted electromagnetic signal with said slotted openings, said transmission line disposed on a bottom surface of the antenna so as to substantially enclose said antenna axis, said transmission line comprising a plurality of m coupling regions, each said coupling region comprising a segment of said transmission line disposed proximate a corresponding said slotted opening such that an electromagnetic signal transmitted through said transmission line is coupled sequentially into respective said slotted openings
• surface of the antenna so as to substantially enclose said antenna axis.

An antenna (10), suitable for transmitting and receiving electromagnetic signals of wavelength λ, the antenna comprising:

• a nonconductive substantially planar substrate (19) having first (13) and second (15) surfaces bounded by a common peripheral edge (17), the peripheral edge enclosing an antenna axis (11) orthogonal to the first and second surfaces;
• a transmission line (21) disposed on the first surface, the transmission line comprising a first end (23), a second end (25), and an inner edge (29) extending between the first and second ends, at least a portion of the inner edge forming an arc of radius R centered on the antenna axis, the transmission line being terminated at the second end by electrical connection to a load impedance (24);
• and
• a conductive layer (31) disposed on the second surface, the conductive layer comprising a plurality of m slotted openings (33), each the slotted opening having one end located within a distance R of the antenna axis and having a width that is substantially less than the length,
• whereby, when an electromagnetic signal is fed into the first end of the transmission line, electromagnetic energy is coupled sequentially into the respective slotted openings such that a radiated signal is transmitted from the slotted openings substantially in the direction of the antenna axis.

An antenna (10), suitable for transmitting and receiving electromagnetic signals of wavelength λ, the antenna comprising:

• a nonconductive substantially planar substrate (19) having first (13) and second (15) surfaces bounded by a common peripheral edge (17), the peripheral edge enclosing an antenna axis (11) orthogonal to the first and second surfaces;
• a transmission line (21) disposed on the first surface, the transmission line comprising a first end (23), a second end (25), and an inner edge (29) extending between the first and second ends, at least a portion of the inner edge forming an arc of radius R centered on the antenna axis;
• and
• a conductive layer (31) disposed on the second surface, the conductive layer comprising a plurality of m slotted openings (33), each the slotted opening having
• one end located within a distance R of the antenna axis,
• a width that is substantially less than the length, and
• an electrical length of integer multiples of λ 4 ,
• with at least one slotted opening spatially separated from an adjacent slotted opening by an angle of 2 ⁢ π m ,
• whereby, when an electromagnetic signal is fed into the first end of the transmission line, electromagnetic energy is coupled sequentially into the respective slotted openings such that a radiated signal is transmitted from the slotted openings substantially in the direction of the antenna axis.