Thin film tape write head for dual frequency operation

A thin film write head for writing a write-equalized digital data stream onto a surface of a magnetic tape, the write-equalized data stream comprising data transitions and equalization pulses, wherein the data transitions occur at a frequency no greater than the data frequency and wherein each equalization pulse is a signal written at an equalization frequency, the equalization frequency much greater than the data frequency, the thin film write head comprising:

• a substrate having an end over which the magnetic tape will pass;
• an insulation layer deposited on the substrate;
• a magnetic bottom pole deposited on the insulation layer;
• a coil structure built over a first portion of the bottom pole located away from the end of the substrate over which the magnetic tape will pass;
• an insulating gap layer over the coil structure and a second portion of the bottom pole, the second portion defining a region located near the end of the substrate over which the magnetic tape will pass and not covered by the coil structure;
• and
• a magnetic top pole deposited on the gap layer, the top pole, the bottom pole, and the coil structure forming an electromagnet operative to write the write-equalized digital data stream onto the magnetic tape by converting an input current through the coil structure to a head field;
• wherein a gap is comprised of the second portion of the bottom pole, a portion of the gap layer above the second portion of the bottom pole, and a portion of the top pole above the second portion of the bottom pole, the gap having a gap depth extending the length of the gap layer above the second portion of the bottom pole in a direction normal to the tape surface;
• and
• wherein the gap depth is set such that saturation occurs at the data frequency thereby generating substantially the same head field amplitude as conversion of the input current at the equalization frequency.

A tape deck for writing write-equalized digital data streams onto magnetic tape comprising:

• a host interface operable to receive data from a host processor and produce an input write signal with a data format suitable for writing on the tape;
• a write equalizer in communication with the host interface, the write equalizer operable to receive the input write signal and produce a write-equalized input signal comprising data transitions and equalization pulses, the data transitions occurring at a frequency no greater than a data frequency and wherein each equalization pulse is a signal written at an equalization frequency, the equalization frequency much greater than the data frequency;
• a write driver in communication with the write equalizer, the write driver operable convert the write-equalized input signal into a write current;
• and
• a thin film write head comprising
• a top pole,
• a bottom pole,
• a conductive coil disposed between a first portion of the top pole and the bottom pole, the top pole, bottom pole, and conductive coil forming an electromagnet operative to write the write-equalized digital data stream onto the magnetic tape by converting an input current through the conductive coil into a head field, the input current magnitude for data transitions expressed as a data transition amplitude, and
• an insulating gap layer disposed between a second portion of the top pole and the bottom pole, the top pole, the bottom pole and the gap layer forming a gap in the electromagnet, the head field generated across the gap, the gap having a gap depth extended to cause saturation to write current at the data frequency and data transition amplitude.