A method and apparatus for processing demodulated data comprising received symbol data is disclosed. A first magnetic layer has an invariable magnetization. The power supply, rather than using heavy, bulky transformers, uses a hybrid high-voltage multiplier that involves an AC coupling circuit and a half-wave rectifier, the outputs of which are coupled in series to a capacitor bank to achieve a 500-volt charging source for the capacitor bank. A slot couples the hole and the upper edge. The ratio of the predetermined thickness to the mouth length is increased until there is no substantial increase in the high frequency limit of the array.