Patent ID: 9673497
Date: 2017-06-06
CPC Classifications: H01P

Claim:
1. A radio-frequency filter of coaxial construction, comprising: at least one resonator having an internal conductor and an external conductor housing; the external conductor housing comprising a housing base, a housing cover arranged at a distance from the housing base, and a peripheral housing wall extending between the housing base and the housing cover, the wall comprising a first material which has a first thermal expansion coefficient; the internal conductor galvanically connected to the housing base and extending in an axial direction from the housing base towards the housing cover; the internal conductor ending at a distance from the housing cover and/or being galvanically separated from the housing cover; a compensation device formed from a second material which has a second thermal expansion coefficient, the second thermal expansion coefficient of the second material being greater than the first thermal expansion coefficient of the first material; and upon a temperature increase, a distance between a free end of the internal conductor and at least one portion of the housing cover increases and, upon a temperature decrease, the distance between the free end of the internal conductor and the at least one portion of the housing cover decreases; the compensation device formed as an integral component of the housing and comprising a wall portion that a) extends in the axial direction and changes in length in said direction in the event of a temperature change, the wall portion being part of the housing wall and being configured in the form of an intermediate layer or an uppermost layer lying adjacent to the housing cover, and/or b) extends in the axial direction or in a direction which extends obliquely thereto and can be changed in length in said direction in the event of a temperature change, the wall portion being an integral part of the housing cover, or forming the housing cover having a convex curvature oriented outwards.