Various embodiments include apparatus and methods related to finding a position in an underground formation. Apparatus and methods can include receiving signals from a receiver in an underground formation in response to signals generated from transmitting sources, each of the transmitting sources located at a known position; and processing the received signals, based on the signals generated from the transmitting sources, to determine the position of the receiver. A number of techniques can be applied to processing the received signal. Additional apparatus, systems, and methods are disclosed.

A radio test system for testing a device under test is described, comprising a signal generation unit configured to generate a downlink signal to be transmitted to the device under test for over-the-air testing. The radio test system has at least one antenna configured to transmit the downlink signal via an over-the-air transmission channel to the device under test. Further, a receiver is provided that is configured to receive a response signal via the over-the-air transmission channel from the device under test. In addition, the radio test system has at least one over-the-air adapter that is connected to the signal generation unit wherein the over-the-air adapter is configured to adapt the downlink signal to be transmitted such that the over-the-air transmission channel is equalized. Further, a method for testing a device under test is described.

An electromagnetic (EM) receiver system for measuring EM signals. The EM receiver system includes a platform; a coil for measuring EM signals; and first to third suspension mechanisms located between the platform and the coil so that the coil oscillates relative to the platform, and the first to third suspension mechanisms attenuate motion induced noise introduced by towing the receiver system above ground.

A method for detecting foreign objects in an induction charging device, with the aid of at least one control and/or regulating unit of the induction charging device, includes: ascertaining a resonance frequency; determining an actual quality at the resonance frequency; and comparing the actual quality to a setpoint quality which is a function of a resonance frequency.

The present invention provides a method and an apparatus for controlling the wireless induction power supply. The apparatus comprises a transmitter control circuit and a receiver control circuit. The method comprises generating a plurality of switching signals for switching a transmitter winding and generating a power; detecting a level of a transmitter signal from the transmitter winding; and controlling a switch to deliver the power from a receiver winding to a load. The receiver winding is coupled to receive the powerfrom the transmitter winding. The switching signals will be disabled if the level of the transmitter signal is not higher than a threshold over a first period or the level of the transmitter signal is higher than a high-threshold over a second period. Accordingly, the method and the apparatus according to the present invention have the foreign object detection (FOD) function for the safety.

Methods and apparatus according to the invention include inductive units or apparatus such as magnetic metal detectors comprising multiple electromagnetic coils and circuit boards such as electronic printed circuit boards (PCBs) so that the circuit boards, while containing metallic surfaces and layers, are positioned in such a way as to reduce or eliminate their effect on the metal detector's coils. The apparatus comprising: a plurality of electromagnetic coils and a plurality of circuit boards, and wherein at least one of said circuit boards is positioned so that its thickness direction is orthogonal to the magnetic field of at least one of said coils.

An electromagnetic (EM) receiver system for measuring EM signals. The EM receiver system includes a platform; a coil for measuring EM signals; and first to third suspension mechanisms located between the platform and the coil so that the coil oscillates relative to the platform, and the first to third suspension mechanisms attenuate motion induced noise introduced by towing the receiver system above ground.

The invention relates to a device having, as a sensor for detecting an object arranged behind an article that is transparent to electromagnetic radiation, a coil assembly having a first transmitting coil (1.1) and a first receiving coil (2.1) arranged orthogonally with respect to the first transmitting. An evaluation unit evaluates the output signals from the coil assembly. The fact that the coil assembly comprises the first transmitting coil (1.1) and at least one further transmitting coil (1.2, 1.3, 1.4), and the first receiving coil (2.1) and at least one further receiving coil (2.2, 2.3, 2.4), wherein axes (1.5, 1.6) of the first and of the at least one further transmitting coil are orthogonal to each other, and the axes (1.5, 1.6) of the first and second transmitting coil intersect the axis (2.5) of the first receiving coil (2.1) that is orthogonal to the first and second transmitting coils (1.1, 1.2), means that a device is provided that reduces or even eliminates the grating effect. According to the method, for this purpose, the electromagnetic fields emitted by the transmitting coils as a result of a periodic AC signal during a first half period are each directed in the direction of the first receiving coil (2.1) and, during the second half period, are directed away from the first receiving call (2.1), wherein the first receiving coil (2.1) is wired and operated in series with at least one further receiving coil (2.2, 2.3, 2.4). An electromagnetic field which penetrates the coil assembly, generates mutually opposed voltages in the receiving coils (2.1, 2.3; 2.2, 2.4).

A metal detection apparatus (9) is tested with a test device (7) having at least one test article (79), movable through a detection zone (60). The test article is moved through the detection zone along a first transfer axis (ca) and a first input signal is measured. A first threshold (th1) is determined, where an amplitude of the first input signal exceeds the first threshold (th1). Then, an identical test article is moved through the detection zone along a further transfer axis (ta; . . . ) and a further input signal is measured and a further threshold (th2; . . . ) is determined, where an amplitude of the further input signal exceeds the further threshold (th2; . . . ). The first or further threshold (th1; th2; . . . ) is selected in the signal processing path (4) whenever the test article is moved along the related transfer axis (ca; ta; . . . ).

Man-portable locator systems for locating buried or otherwise inaccessible pipes, conduits, cables, wires and inserted transmitters using detector arrays and stochastic signal processing and similar techniques to analyze and display multiple target objects at differing frequencies in a layered user interface (UI) are disclosed.