BTE hearing aid having a balanced antenna
A behind the ear hearing aid includes: a transceiver for wireless data communication interconnected with an antenna for electromagnetic field emission and electromagnetic field reception, the antenna extending on a first side of a hearing aid and a second side of the hearing aid, a first segment of the antenna extending from proximate the first side of the hearing aid to proximate the second side of the hearing aid; and a feed system configured for exciting the antenna to induce a current in at least the first segment, the current having a first local maxima proximate the first side of the hearing aid and a second local maxima proximate the second side of the hearing aid.
1. A behind the ear hearing aid comprising:
a microphone for reception of sound and conversion of the received sound into a corresponding first audio signal;
a signal processor for processing the first audio signal into a second audio signal compensating a hearing loss of a user of the hearing aid;
a receiver that is connected to an output of the signal processor for converting the second audio signal into an output sound signal;
a transceiver for wireless data communication interconnected with an antenna for electromagnetic field emission and electromagnetic field reception, the antenna extending on a first side of the hearing aid and a second side of the hearing aid, a first segment of the antenna extending from proximate the first side of the hearing aid to proximate the second side of the hearing aid; and
a feed system configured for exciting the antenna to induce a current in at least the first segment, the current having a first local maxima proximate the first side of the hearing aid and a second local maxima proximate the second side of the hearing aid.
2. The hearing aid according to claim 1 , wherein the antenna is a balanced antenna.
3. The hearing aid according to claim 1 , wherein a part of the antenna extending proximate the first side of the hearing aid is substantially identical to a part of the antenna extending proximate the second side of the hearing aid.
4. The hearing aid according to claim 1 , wherein the feed system comprises a first feed point for exciting at least the antenna proximate the first side of the hearing aid and a second feed point for exciting at least the antenna proximate the second side of the hearing aid.
5. The hearing aid according to claim 1 , wherein the first segment has a direction substantially orthogonal to a surface of a head of the user when the hearing aid is worn in its operational position by the user.
6. The hearing aid according to claim 1 , wherein the first segment is configured to short circuit a part of the antenna proximate the first side of the hearing aid and a part of the antenna proximate the second side of the hearing aid to provide a current bridge between the first side of the hearing aid and the second side of the hearing aid.
7. The hearing aid according to claim 1 , wherein a part of the antenna extending proximate the first side of the hearing aid and/or a part of the antenna extending proximate the second side of the hearing aid has the shape of a monopole antenna structure.
8. The hearing aid according to claim 6 , wherein one or each of (1) a length of the part of the antenna extending proximate the first side of the hearing aid and (2) a length of the part of the antenna extending proximate the second side of the hearing aid, as measured from the short circuit to a free end, is substantially lambda/4.
9. The hearing aid according to claim 1 , wherein a part of the antenna extending proximate the first side of the hearing aid and/or a part of the antenna extending proximate the second side of the hearing aid has a circumference of lambda/2.
10. The hearing aid according to claim 1 , wherein the antenna comprises an annulus shaped antenna structure having a circumference of lambda/2.
11. The hearing aid according to claim 1 , wherein a part of the antenna extending proximate the first side of the hearing aid comprises a first resonant structure and/or a part of the antenna extending proximate the second side of the hearing aid comprises a second resonant structure.
12. The hearing aid according to claim 4 , wherein the hearing aid has a plane of partition extending between the first side of the hearing aid and the second side of the hearing aid, and wherein at least a part of the antenna intersects the plane of partition at an intersection, and wherein a relative difference between a distance from the first feed point to the intersection and a distance from the second feed point to the intersection is less than or equal to a first threshold.
13. The hearing aid according to claim 12 , wherein the plane of partition comprises a symmetry plane for the first and second antenna structures.
14. The hearing aid according to claim 12 , wherein the threshold is less than 25%.
15. The hearing aid according to claim 4 , wherein a distance between the first feed point and a short circuit, and a distance between the second feed point and the short circuit, respectively, are tailored to achieve a desired antenna impedance.