BTE hearing instrument comprising an open-end transmission line antenna

A hearing instrument comprising a behind-the-ear part (BTE), the BTE part comprising:

• a first side, a second side substantially parallel to the first side, and a third side physically coupling the first side and the second side,
• wherein the third side is configured to be substantially perpendicular to skin of a user when the BTE part is worn behind an ear,
• an antenna,
• a transceiver configured for transmission and reception at frequencies from 1 to 6 GHz and connected to the antenna via a non-radiating bifilar transmission line,
• wherein the antenna comprises a radiating bifilar transmission line having an open connection at one end and comprising two conducting legs parallel to each other at a distance of at least 2.0 mm and connected at the end opposite to an open end by an impedance matching base portion configured to match a lower impedance of the antenna to a higher impedance of the non-radiating transmission line,
• wherein the non-radiating transmission line is connected via the impedance matching base portion to the antenna with two strands of the non-radiating transmission line connected to a different one of the conducting legs of the radiating transmission line, and
• wherein each of the conducting leg extends along a peripheral region along a length of the third side of the BTE.