Abstract: The present invention provides a better electromagnetic lens, a method for producing it and a lens antenna. The electromagnetic lens is a winded body made of a strip material. The dielectric constant of a dielectric material gradually changes in both a transverse direction and a longitudinal direction of the strip material. After the strip material is winded to be a winded body, the dielectric material is distributed in at least one artificially predetermined three-dimensional space range called a lens body inside the winded body. A part of the winded body besides the lens body is called a non-lens part. The dielectric constant of the lens body is not lower than that the dielectric constant of the non-lens part.

Abstract: The present invention provides a better electromagnetic lens, a method for producing it and a lens antenna. The electromagnetic lens is a winded body made of a strip material. The dielectric constant of a dielectric material gradually changes in both a transverse direction and a longitudinal direction of the strip material. After the strip material is winded to be a winded body, the dielectric material is distributed in at least one artificially predetermined three-dimensional space range called a lens body inside the winded body. A part of the winded body besides the lens body is called a non-lens part. The dielectric constant of the lens body is not lower than that the dielectric constant of the non-lens part.

Abstract: The present invention proposes a large industrial vacuum sealer system. The system comprises the following working steps: after materials are placed, a box base moves upwards to be jointed with a box cover in a sealing manner; the first valve 120 is switched on; a rotary vane pump starts roughly pumping the air; next, a roots pump starts working; when the pressure reaches a preset value, the first valve 120 is switched off; valves 110 and the second valve 130 are switched on; diffusion pumps start working; after the air is pumped out completely, all pumps stop working. A box body comprises the box cover and the box base, wherein the box body is fixedly mounted. The box base is driven by air cylinders to move along a rail. In the present invention, a light curtain sensor is mounted between the box cover and the box base.

Abstract: The present invention proposes a large industrial vacuum sealer system. The system comprises the following working steps: after materials are placed, a box base moves upwards to be jointed with a box cover in a sealing manner; the first valve 120 is switched on; a rotary vane pump starts roughly pumping the air; next, a roots pump starts working; when the pressure reaches a preset value, the first valve 120 is switched off; valves 110 and the second valve 130 are switched on; diffusion pumps start working; after the air is pumped out completely, all pumps stop working. A box body comprises the box cover and the box base, wherein the box body is fixedly mounted. The box base is driven by air cylinders to move along a rail. In the present invention, a light curtain sensor is mounted between the box cover and the box base.