Abstract: An antenna including a planar conductor, in which the planar conductor is self-supporting and the radiating pattern of the antenna is substantially isotropic.

Abstract: A planar dipole antenna is arranged on a non-conductive substrate having an exposed, planar surface. The antenna includes a first quarter wavelength element having a first end and an opposite second end and a second quarter wavelength element having a third end and an opposite fourth end. The first, second, third and fourth ends, respectively, are arranged on a common straight line with the second and third ends adjacent to each other. A third quarter wavelength element, having a fifth end and an opposite sixth end, is arranged adjacent to the first element with its fifth end adjacent to the first end of the first element and its sixth end both adjacent to and physically connected with the third end of the second element. A signal source or sink is coupled to the first end of the first element and the fifth end of the third element, respectively, for providing electrical energy to, and/or receiving electrical energy from the antenna.

Abstract: An apparatus for coupling energy into and out of a SAW device which can serve as a transponder in a "passive interrogator label system". The device includes a conductive loop deposited on the active surface of the piezoelectric substrate which is electrically connected at its ends to the two transducer terminals of the SAW. The conductive loop forms an inductive element for coupling energy into and out of the SAW device. The active surface of the device is protected by a non-conductive cover (e.g. glass) adhered to the surface.

Abstract: A transponder for use in an interrogator/transponder system includes a piezoelectric substrate for coupling electrical energy into and/or out of a surface acoustic wave (SAW) device; a first inductive loop inductively coupled to a conductive loop on the substrate, a second inductive loop inductively coupled to the first inductive loop for transmitting and/or receiving electrical signals to and/or from the SAW device. The first inductive loop forms an intermediate inductive coupling path between the second inductive loop of the transmitter/receiver and the conductive loop on the substrate.