Electromagnetic navigation antenna assembly and electromagnetic navigation system including the same

An electromagnetic navigation system comprising:

• an antenna assembly configured to radiate electromagnetic fields, the antenna assembly including:
• a substrate having a plurality of layers;
• and
• a plurality of groups of planar antennas, each of the planar antennas including a respective trace deposited on a respective layer of the plurality of layers and arranged in a respective plurality of loops,
• each of the groups of planar antennas including a first planar antenna, a second planar antenna, and a third planar antenna,
• wherein, for each of the plurality of groups of planar antennas:
• an innermost loop of the first planar antenna has a first linear portion and a second linear portion approximately perpendicular to the first linear portion,
• an innermost loop of the second planar antenna has a first linear portion and a second linear portion approximately perpendicular to the first linear portion and longer than the first linear portion,
• an innermost loop of the third planar antenna has a first linear portion and a second linear portion approximately perpendicular to the first linear portion and longer than the first linear portion,
• the first linear portion of the innermost loop of the second planar antenna is approximately parallel to the first linear portion of the innermost loop of the first planar antenna, and
• the first linear portion of the innermost loop of the third planar antenna is approximately parallel to the second linear portion of the innermost loop of the first planar antenna;
• a catheter;
• an electromagnetic sensor affixed to the catheter and configured to receive one or more signals based on the radiated electromagnetic fields;
• a processor;
• and
• a memory including instructions that, when executed by the processor, cause the processor to calculate at least one of a location or an orientation of the electromagnetic sensor based on the received one or more signals.