Abstract: A miniaturized thin-wire multi-turn series-connected helical loop antenna, the volutes of which are concentric turns, closely spaced so as to exhibit strong mutual coupling effects. A lumped impedance, fixed or variable, is disposed electrically in series with one of the turns, and a selectively actuable multi-position switch interconnects the turns and the lumped impedance to maximize efficiency.BACKGROUND OF THE INVENTION1. Field of the InventionThe subject invention relates to miniaturized multi-turn series-connected loop antennas.2. Description of the Prior ArtThe theoretical solution for multi-turn loop antennas, whether transmitting or receiving, is initially based on the solution for a single-turn loop. The single-turn solution can be obtained by considering the antenna to be a transducer which converts concentrated or distributed voltages into distributed fields and vice-versa. The phenomenon which accomplishes this is the flow of current on the antenna conductor.