A permanent magnet comprising an antiferromagnetic layer and a ferromagnetic layer having a first sub-layer made of a first type of ferromagnetic material, the first type of ferromagnetic material being an at least partially crystallized alloy of iron and cobalt, and a second sub-layer made of a second type of ferromagnetic material, this second type of ferromagnetic material also being an alloy of iron and cobalt in which the proportion of face-centered cubic crystals is less than the proportion of face-centered cubic crystals in the first type of ferromagnetic material.

A vehicle navigation system includes an external source sensor onboard a vehicle system that determines headings of the vehicle system. The external source sensor determines the headings using signals received from an off-board, external system. The navigation system also includes a magnetic sensor onboard the vehicle system that measures magnetic fields along different axes at different times. One or more processors determine a combination of the magnetic fields, determine a position translation and/or a magnitude scaling of the combination of the magnetic fields, and modify at least one of the headings based on the position translation and/or the magnitude scaling.

A test system for measuring beam characteristics of a device under test (DUT) is provided. The system comprises a DUT, a measurement antenna configured to receive electro-magnetic radiation emitted by the DUT, a link antenna configured to provide a test communication link to the DUT, and a control and analyzing unit configured to control a beam steering of the device under test and to analyze signals from the device under test received by the measurement antenna. The test communication data transmitted to the device under test comprises beam steering control data in order to control the beam steering of the DUT.

A test system for measuring beam characteristics of a device under test (DUT) is provided. The system comprises a DUT, a measurement antenna configured to receive electro-magnetic radiation emitted by the DUT, a link antenna configured to provide a test communication link to the DUT, and a control and analyzing unit configured to control a beam steering of the device under test and to analyze signals from the device under test received by the measurement antenna. The test communication data transmitted to the device under test comprises beam steering control data in order to control the beam steering of the DUT.

One embodiment is a magnetic field measurement system that includes at least one magnetometer having a vapor cell, a light source to direct light through the vapor cell, and a detector to receive light directed through the vapor cell; at least one magnetic field generator disposed adjacent the vapor cell; and a feedback circuit coupled to the at least one magnetic field generator and the detector of the at least one magnetometer. The feedback circuit includes at least one feedback loop that includes a first low pass filter with a first cutoff frequency. The feedback circuit is configured to compensate for magnetic field variations having a frequency lower than the first cutoff frequency. The first low pass filter rejects magnetic field variations having a frequency higher than the first cutoff frequency and provides the rejected magnetic field variations for measurement as an output of the feedback circuit.

One embodiment is a magnetic field measurement system that includes at least one magnetometer having a vapor cell, a light source to direct light through the vapor cell, and a detector to receive light directed through the vapor cell; at least one magnetic field generator disposed adjacent the vapor cell; and a feedback circuit coupled to the at least one magnetic field generator and the detector of the at least one magnetometer. The feedback circuit includes at least one feedback loop that includes a first low pass filter with a first cutoff frequency. The feedback circuit is configured to compensate for magnetic field variations having a frequency lower than the first cutoff frequency. The first low pass filter rejects magnetic field variations having a frequency higher than the first cutoff frequency and provides the rejected magnetic field variations for measurement as an output of the feedback circuit.

A method is disclosed. In one example, the method includes bonding a first panel of a first material to a base panel in a first gas atmosphere, wherein multiple hermetically sealed first cavities encapsulating gas of the first gas atmosphere are formed between the first panel and the base panel. The method further includes bonding a second panel of a second material to at least one of the base panel and the first panel, wherein multiple second cavities are formed between the second panel and the at least one of the base panel and the first panel.

A passive magnetic flux detector (PMFD) is provided for indicating an ambient magnetic field. The PMFD includes a coil, a rectifier, and an indicator. The indicator is either a light emitting diode (LED), a piezoelectric speaker or both.

An electromagnetic tracking system including a patient support element and an electromagnetic field generator. The patient support element is superposed relative to the electromagnetic field generator, and the electromagnetic field generator is selectively moveable relative to the patient support element.

An electromagnetic tracking system including a patient support element and an electromagnetic field generator. The patient support element is superposed relative to the electromagnetic field generator, and the electromagnetic field generator is selectively moveable relative to the patient support element.