The temperature test apparatus includes an OTA chamber 50 as an anechoic box, a heat insulating housing that is accommodated in the OTA chamber, a temperature control device that controls a temperature in the heat insulating housing, a ventilation block 210 that is made of metal and provided to block an opening 502 formed in the OTA chamber, and in which a plurality of through-holes 214 are formed, a first cover 220 that is provided on an outer side of the OTA chamber to cover the ventilation block, and form a first space 225 with the ventilation block, and is joined to a pipe for air from the temperature control device, and a second cover 250 that is provided on an inner side of the OTA chamber to cover the ventilation block, and form a second space 255 communicating with the heat insulating housing, together with the ventilation block.

A radio frequency (RF) test hat. The RF test hat may comprise: a cylinder having forward and aft ends, end cap, arm and strap assembly, first and second absorber materials, a receiving antenna, and lens. The end cap may couple to the forward end of the cylinder. The arm and strap assembly may hingedly couple to the aft end of the cylinder and may be configured to mount the RF test hat onto a pod or transmitting antenna. The first absorber material may be located within the forward end of the cylinder. The second absorber material may be located near the aft end of the cylinder. The receiving antenna, which may be disposed within the first absorber material, may measure the intensity of a beam of electromagnetic radiation. The lens, which may be located within the middle portion of the cylinder, may spread the beam across a larger surface area of the first absorber material.

Method for evaluating electromagnetic performance of a permanent-magnet machine, wherein the method is implemented in a computer processer or in a controller of a permanent-magnet machine, calculating the magnetic field distribution by a sub-domain method; using current density of the equivalent current sheet to represent the boundary condition, iterating by the sub-do-main method and by the magnetic circuit method until a convergent result is obtained, calculating the electro-magnetic performance parameters on basis of the convergent result, so as to evaluate the electromagnetic performance.

A system for parallel measurement of devices under test in an open over the air environment is provided. The system comprises a plurality of alignment structures, each comprising a shaped reflector arranged at a top end of the alignment structure and an antenna arranged at the focal region of the shaped reflector. In this context, the devices under test are arranged at bottom ends of the plurality of alignment structures, opposite to a respective shaped reflector. In addition, the plurality of alignment structures are placed parallel to each other without shielded enclosures.

The temperature test apparatus includes a test antenna for measuring transmission and reception characteristics of a DUT, an anechoic box formed by a metal housing having an internal space, a heat insulating housing, a temperature control device that controls the temperature of a spatial region, and a measurement device that measures the transmission and reception characteristics of the DUT. The temperature control device and the heat insulating housing are connected to each other by a pipe 31 through which a gas for controlling the temperature of the spatial region passes and that goes through the metal housing. A portion 31A of the pipe from the metal housing to a predetermined position of the internal space is made of metal. A metal net portion 33 that blocks a pipeline 31Ae of a portion of the pipe 31 is provided.

In a general aspect, a vapor cell is presented that includes a dielectric body. The dielectric body has a surface that defines an opening to a cavity in the dielectric body. The vapor cell also includes a vapor or a source of the vapor in the cavity of the dielectric body. An optical window covers the opening of the cavity and has a surface bonded to the surface of the dielectric body to form a seal around the opening. The seal includes metal-oxygen bonds formed by reacting a first plurality of hydroxyl ligands on the surface of the dielectric body with a second plurality of hydroxyl ligands on the surface of the optical window.

In a general aspect, a method of manufacturing a vapor cell is presented. The method includes obtaining a dielectric body having a surface that defines an opening to a cavity in the dielectric body. The method also includes obtaining an optical window that includes a surface. The surfaces of the dielectric body and the optical window are altered to include, respectively, a first plurality of hydroxyl ligands and a second plurality of hydroxyl ligands. The method additionally includes disposing a vapor, or a source of the vapor, into the cavity. The altered surface of the dielectric body is contacted to the altered surface of the optical window to form a seal around the opening to the cavity. The seal includes metal-oxygen bonds formed by reacting the first plurality of hydroxyl ligands with the second plurality of hydroxyl ligands during contact of the altered surfaces.

A system for parallel measurement of devices under test in an open over the air environment is provided. The system comprises a plurality of alignment structures, each comprising a shaped reflector arranged at a top end of the alignment structure and an antenna arranged at the focal region of the shaped reflector. In this context, the devices under test are arranged at bottom ends of the plurality of alignment structures, opposite to a respective shaped reflector. In addition, the plurality of alignment structures are placed parallel to each other without shielded enclosures.

A temperature test apparatus 1 includes a test antenna 6 configured to transmit or receive a radio signal to or from the antennas 110 in order to measure reception characteristics or transmission characteristics of the DUT 100, a heat-insulating housing 70 made of heat-insulating material surrounding a space region 71 including a quiet zone QZ, and a measuring device 20 configured to measure the transmission characteristics or the reception characteristics of the DUT 100. The heat-insulating housing 70 has a flat plate shaped part 70a in a region through which radio waves of a radio signal transmitted from the test antenna 6 passes before entering the quiet zone QZ. The flat plate shaped part 70a is perpendicular to the traveling direction of the radio waves of the radio signal entering the quiet zone QZ.

In a general aspect, a vapor cell is presented that includes a dielectric body. The dielectric body has a surface that defines an opening to a cavity in the dielectric body. The vapor cell also includes a vapor or a source of the vapor in the cavity of the dielectric body. An optical window covers the opening of the cavity and has a surface bonded to the surface of the dielectric body to form a seal around the opening. The seal includes metal-oxygen bonds formed by reacting a first plurality of hydroxyl ligands on the surface of the dielectric body with a second plurality of hydroxyl ligands on the surface of the optical window.