What is the difference between slat and tile arrays in active phased arrays?

[senmeis]

Hi,

I’m reading the attached pdf article at https://www.microwavejournal.com/art...neration-radar about tile architecture in active phased arrays. Please help me with the following two questions.

1. Figure 2: Are this figure and the attached architecture (array.jpg) referred to the same structure?
2. It seems the radiating direction of the elements in tile arrays (Figure 3) is perpendicular to the plain. What about the radiating direction in slat arrays?

Senmeis

 

[tech99]

It looks as if the difference between slat and tile arrays is nothing to do with the antenna itself but is concerned with the packaging of the electronics on to PCBs.
The slat array is an older system where the PCBs are arranged edge on to the face of the array, proving lots of space for electronics. The tile arrays use PCBs flat on the face of the array, so that there is much less component space but it is cheaper.

 

[senmeis]

I’m not sure if the elements are the same. It seems to me the elements in Figure 2 are patch antennas which are perpendicular to the face of the array, but the elements in Figure 3 are parallel to the face of the array.

 

[tech99]

Sorry, I do not have access to the Microwave journal. It is possible the tile uses patch antennas and the slat uses printed dipoles.

 

[marcusl]

I’m not sure if the elements are the same. It seems to me the elements in Figure 2 are patch antennas which are perpendicular to the face of the array, but the elements in Figure 3 are parallel to the face of the array.

This is correct, however both elements radiate perpendicular to the array plane.

 

[senmeis]

The original article is already attached. I don’t understand why elements in Figure 3 radiate perpendicular to the array plane. I always think the radiating direction of patch antenna is parallel to the pad plane.

 

[marcusl]

Because they are a metal surface approximately one-half wavelength that is mounted on a dielectric above a ground plane. It resonates and sets up big fields at its edges (from patch to ground plane). These fields resemble those from a slot radiator and launch radiation normal to the patch.

 

[tech99]

The original article is already attached. I don’t understand why elements in Figure 3 radiate perpendicular to the array plane. I always think the radiating direction of patch antenna is parallel to the pad plane.

A patch resembles two slots cut in the ground plane. Each slot radiates over a complete 180 degree sector normal to its length. So you are right there is radiation along the ground plane. But as there are two slots, they form a broadside array with half wave spacing and the same phase, so they cancel radiation along the ground plane, leaving a maximum normal to the ground plane.

 

[tech99]

A patch resembles two slots cut in the ground plane.

Incidentally, the radiation from a slot is caused when electrons in the metal are accelerated by the transmitter. The fields in the slot do not do the radiating.