Abstract: In a non-contact IC card, a driving portion 5 sequentially switches a resonance frequency of a resonance circuit 1. A reference voltage generating portion 6 receives an output voltage of resonance circuit 1 for outputting a prescribed reference voltage. An output value measuring portion 7 measures a magnitude of the output voltage of resonance circuit 1 at each resonance frequency using the reference voltage as a reference. An output value storing portion 8 stores a measurement value (an output value). A manner determining portion 9 selects the largest one of the output values stored in output value storing portion 8, and determines a switching manner corresponding thereto as a suitable switching manner. Thus, the suitable switching manner allowing the most efficient power supply can be achieved.

Abstract: A portable communication device uses a first electrostatic antenna element and a second electrostatic antenna element and circuitry which is coupled to the first antenna element and to the second antenna element and which derives operating power from an electrostatic field in the vicinity of the first and second antenna elements. The electrostatic field may be provided by an array of exciter elements containing both horizontal and vertical exciter elements so that at some point as a communication device is moved across the exciter antenna array, the device will have sufficient power coupled to it to power up and become operational.