Abstract: The transmitting and/or receiving antenna of an electronic article surveillance system utilizes a paired-lead loop configuration. One lead forms the active loop.The other lead forms a passive loop, which parallels and is mutually coupled to the active loop, but not conductively connected to it. This other lead is resistively loaded.The passive loop of the receiving antenna can also be used to conduct signals between the receiver circuitry and the alarm reporting devices associated with the receiver.

Abstract: A single-crystal oscillator comprising a single transistor and a capacitor divider connected in a feedback path, which includes the crystal input and output ports, between the collector and base of the transistor, thereby to provide a low-impedance input port to the crystal. The impedance of the crystal output port, which is connected to the base of the transistor, is also low. As a result of the low crystal input and output port impedances, the oscillator is capable of operating without any significant levels of spurious crystal frequencies, and can be switched between crystal and voltage-controlled modes of operation without frequency pull or lock-up to the crystal when operating in the voltage-controlled mode.