Microwave filter having a fine temperature drift tuning mechanism

Patent metadata

Field	Value
Publication number	US-10158154-B2
Application number	US-201515115614-A
Country	US
Kind code	B2
Filing date	Jan 19, 2015
Priority date	Jan 31, 2014
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

A microwave filter comprises at least one resonant filter element resonating at a resonant frequency and having a housing, a resonant filter cavity arranged in the housing and a resonator element arranged in the housing. At least two tuning elements are arranged on the housing of the resonant filter element and each extend into the cavity with a shaft portion, wherein the two tuning elements are movable with respect to the housing to adjust the length of the shaft portion extending into the housing and wherein the at least two tuning elements are constituted and designed such that by adjusting the length of the shaft portion of each tuning element extending into the housing a temperature drift of the resonant frequency is adjustable.

First claim

The invention claimed is:

1. A microwave filter, comprising at least one resonant filter element resonating at a resonant frequency, each resonant filter element comprising:
a housing;
a resonant filter cavity arranged in the housing; and
a resonator element arranged in the housing, wherein
at least two tuning elements are arranged on the housing of the resonant filter element and each extend into the cavity with a shaft portion, wherein the at least two tuning elements are movable with respect to the housing to adjust a length of the shaft portion extending into the housing, and wherein the at least two tuning elements are constituted and designed such that by adjusting the length of the shaft portion of each tuning element extending into the housing a temperature drift of the resonant frequency is adjustable, wherein the at least two tuning elements are arranged symmetrically with respect to the resonator element, wherein each of the at least two tuning elements extend from a housing wall into a respective opening of the resonator element, wherein each opening partially extends into a shaft body of the resonator element from a top face of the resonator element.

2. The microwave filter of claim 1 , wherein, for each resonant filter element, a first of the at least two tuning elements, at a given adjustment position, has the effect of increasing the resonant frequency with increasing temperature of the microwave filter, whereas a second one of the at least two tuning elements, at a given adjustment position, has the effect of decreasing the resonant frequency with increasing temperature of the microwave filter.

3. The microwave filter of claim 1 , wherein, for each resonant filter element, the at least two tuning elements are movable with respect to the housing independent of each other.

4. The microwave filter of claim 1 , wherein, for each resonant filter element, the at least two tuning elements are made of a metallic material or a dielectric material.

5. The microwave filter claim 1 , wherein, for each resonant filter element, the at least two tuning elements comprise a different material and/or shape.

6. The microwave filter claim 5 , wherein, for each resonant filter element, the different materials comprise a different thermal expansion coefficient.

Assignees

• Andrew Wireless Systems Gmbh

Inventors

• Tkadlec Roman
• Hrnicko Frantisek
• Toth Gabriel

Classifications

• H01P1/208

  Cascaded cavities; Cascaded resonators inside a hollow waveguide structure (H01P1/205 takes precedence) · CPC title

• H01P1/30

  for compensation of, or protection against, temperature or moisture effects {; for improving power handling capability (H01P1/04, H01P1/08 take precedence)} · CPC title

• H01P1/2053 Primary

  the coaxial cavity resonators being disposed parall to each other · CPC title

• H01P7/04

  Coaxial resonators · CPC title

• H01P1/2084

  with dielectric resonators · CPC title