Slot Waveguide Array

Slotted waveguide arrays consist of a number of slots cut into the walls of a waveguide forming an array with the slots acting as individual radiating elements.

The specific design task here is a 10-element transversal slot array cut into the upper wide side of a WR-51 standard rectangular waveguide. The operating frequency is the center of the K band, 8.5 GHz.

Slot radiators or slot antennas are antennas that are used in the frequency range from about 300 MHz to 25 GHz. They are often used in navigation radar usually as an array fed by a waveguide. But also older large phased array antennas used the principle because the slot radiators are a very inexpensive way for frequency scanning arrays. Slot antennas are an about λ/2 elongated. A compact substrate integrated waveguide (SIW) antenna array that operates at 28 GHz and 38 GHz is proposed for fifth generation (5G) applications. The proposed array consists of four SIW cavities fabricated on one single layer of substrate. Each cavity implements a rhombic slot and a triangular-split-ring slot, resonating on TE 101 and TE102 modes at 28 GHz and 38&#.

Single slot model requires only 231 unknowns thanks to higher order MoM applied in WIPL-D Pro 3D EM Solver. The array model is built by using the single slot model and applying a single Copy operation to create the other 9 array elements. That model requires only 1149 unknowns. Single slot simulation lasts under a second on a standard desktop PC or any low-end laptop with dual or quad core CPU, while the array simulation lasts only a few seconds.

Section: Arrays & Radomes

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I claim:

1. A circularly polarized crossed slot waveguide antenna array comprising:

at least a first pair of waveguides supporting only the TE₁₀ mode disposed side by side, each of said first pair of waveguides having a first broad wall facing in the same direction, each of said first broad walls having a longitudinal center line; and

Waveguide Slot Array Design

a first plurality of crossed slots disposed in each of said first broad walls parallel to and spaced from said center line, each of one half of said first plurality of crossed slots on one side of a central area of each of said first broad walls between both extremities of each of said first pair of waveguides being disposed on one side of said center line and each of the other half of said first plurality of crossed slots on the other side of said central area being disposed on the other side of said center line, said first plurality of crossed slots in one of said first broad walls being spaced from said first plurality of crossed slots in the other of said first broad walls a predetermined amount;

said first pair of waveguides and each of said first plurality of crossed slots cooperating to provide a single beam, circularly polarized antenna pattern for said array; each of said first pair of waveguides are excited at both extremities thereof for transmission of circularly polarized radiation, both extremities of one of said first pair of waveguides being excited out of phase with both extremities of the other of said first pair of waveguides to produce in-phase excitation of said first plurality of crossed slots; and a second pair of waveguides each disposed orthogonally to a second broad wall of a different one of said first pair of waveguides, each of said second broad walls being parallel to an associated one of said first broad walls, each of said second pair of waveguides intersecting an associated one of said second broad walls in a central area thereof intermediate said both extremities to receive circularly polarized radiation received by said array.

2. An antenna array according to claim 1, wherein

said predetermining amount is one half of the waveguide wavelength.

3. An antenna array according to claim 2, further including

Waveguide Slot Array With Cavities

additional pairs of waveguides disposed side by side with each other and said first pair of waveguides, said additional pairs of waveguides being identical to said first pair of waveguides, and

additional pluralities of crossed slots disposed in each of said additional pairs of waveguides identical to said first plurality of slots.

4. An antenna array according to claim 1, further including

additional pairs of waveguides disposed side by side with each other and said first pair of waveguides, said additional pairs of waveguides being identical to said first pair of waveguides, and

additional pluralities of crossed slots disposed in each of said additional pairs of waveguides identical to said first plurality of slots.

5. A circularly polarized crossed slot waveguide antenna array comprising:

at least a first pair of waveguides disposed side by side each having a first broad wall facing in the same direction, each of said first broad walls having a longitudinal center line;

a plurality of crossed slots disposed in each of said first broad walls parallel to and spaced from said center line, each of one half of said plurality of crossed slots on one side of a central area of each of said first broad walls between both extremities of each of said pair of waveguides being disposed on one side of said center line and each of the other half of said plurality of crossed slots on the other side of said central area being disposed on the other side of said center line, said slots in one of said first broad walls being spaced from said slots in the other of said first broad walls a predetermined amount;

said first pair of waveguides and each of said plurality of crossed slots cooperating to provide a single beam, circularly polarized antenna pattern for said array; each of said first pair of waveguides are excited at both extremities thereof for transmission of circularly polarized radiation, both extremities of one of said first pair of waveguides being excited out of phase with both extremities of the other of said first pair of waveguides to produce in-phase excitation of said first plurality of crossed slots and

a second pair of waveguides each disposed orthogonally to a second broad wall of a different one of said first pair of waveguides, each of said second broad walls being parallel to an associated one of said first broad walls, each of said second pair of waveguides intersecting an associated one of said second broad walls in a central area thereof intermediate said both extremities of said first pair of waveguides to only receive circularly polarized radiation received by said array.