The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 09, 2000
Filed:
Jan. 14, 1998
Peter M Flowerdew, Bristol, GB;
Plantronics, Inc., Santa Cruz, CA (US);
Abstract
Communication systems requiring a user to wear a headset or body pack preferably include small aerials that use ferrite cores to achieve transmission efficiency. Driving such aerials typically requires the use of a transformer to obtain the strongest possible magnetic field where only a limited supply voltage is available. The limited supply voltage is addressed by combining a step-up transformer and an aerial array on a single permeable core. The transformer includes a primary winding and a secondary winding that are wound along the circumference of the circular cross-section of a toroidal core. The aerial array includes a transmit winding and a receive winding. The transmit winding is wound along the diameter of the toroidal core and the receive winding is wound along the circumference of the toroidal core. In one embodiment, the receive winding is divided into two matching halves. The voltages induced in each half of the receive winding are amplified and summed such that voltages induced by the local transmit winding are canceled while those voltages induced from a transmit winding in a second, distant unit are summed. In another embodiment, a plurality of transmit windings are wound on the core for producing fluxes which are summed in the core and generate a single magnetic induction field.