A security tag used with an electronic security system comprises a dielectric substrate having first and second opposite principal surfaces and a resonant circuit capable of resonating at a frequency within a detection frequency range. The resonant circuit is formed, in part, by a first conductive area on the first substrate surface and a second conductive area on the second substrate surface, the two conductive areas being generally aligned with one another to establish a capacitor with the sub...

A system for electrically contacting a semiconductor wafer during implanting of the wafer includes one or more pairs of closely spaced contacts located adjacent the semiconductor wafer and a driving circuit connected to the contacts to provide a discharge from one contact to the semiconductor wafer and from the semiconductor wafer to the other contact of each pair of contacts. The contacts can be spaced apart from the wafer and the tips of the contacts closest to the wafer may have sharp points ...

In one embodiment, a system includes at least two detector devices, each detector device for independently detecting a phase event of a composite signal comprising one or more traveling wave signals to provide phase event information. The system further includes a processor configured to receive the phase event information from each detector device and to estimate a direction of arrival of at least one of the traveling wave signals based on the phase event information.

There is disclosed a novel compact power oscillator which is normally quiescent until applied to a load, to produce, under load, a unique waveform which has a unique application to self-protective devices and medical uses. The oscillator includes a high gain inverting amplifier, preferably a Darlington pair constituted by a germanium output transistor driven by a small signal transistor, a transformer, a D.C. source such as a battery, and a pair of output electrodes.

An apparatus and method for measuring electrical parameters of a medium such as electrical conductivity and dielectric constant between a pair of electrodes are disclosed. The medium can be a liquid, gas, powder, etc., and the electrodes can be coaxial metallic circular cylinders. To compute electrical conductivity, the device is immersed in the medium to an immersion depth and the conductance across the electrodes is determined. The measurement is repeated at at least one additional immersion d...

A system for characterizing coatings and substrates of a material under test. A sensor is positioned against a coated sample which is to be measured to obtain phase and magnitude measurements. Penetration depth of the magnetic waves of the sensor is a function of frequency. Measurements are made at each of a plurality of signal frequencies. The measured phase and magnitude data is applied with respect to a frequency independent parameter, such as conductivity, using a grid method. The conductivi...