# US 9,882,792 B1 · Filter component tuning method

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- Number: US 9,882,792 B1
- Document ID: US9882792B1
- Status: Granted
- Kind: B1
- Application number: 15/227,169
- Filed: 2016-08-03
- Published: 2018-02-08
- Granted: 2018-01-30
- Earliest claimed: 2016-08-03
- Assignees: Nokia Solutions and Networks Oy
- Applicants: Nokia Solutions and Networks Oy
- Inventors: Steven J. Cooper; David R. Hendry
- Web page: https://patentgrep.com/patent/US9882792B1

## CPC

- H03H 3/00: Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
- G01R 23/07: using response of circuits tuned on resonance, e.g. grid-drip meter
- H01P 1/2086: {multimode}
- H01P 7/06: Cavity resonators
- H01P 7/105: {Multimode resonators}
- H01P 11/008: {Manufacturing resonators}
- H03H 3/013: for obtaining desired frequency or temperature coefficient ({H03H3/0076} H03H3/04, H03H3/10 take precedence)
- H04B 7/0456: Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
- H04L 7/0276: {Self-sustaining, e.g. by tuned delay line and a feedback path to a logical gate}
- H04L 43/028: by filtering
- Y10T 29/49016: Antenna or wave energy "plumbing" making
- H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P)
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- H01P: WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE (operating at optical frequencies G02B)
- H04B: TRANSMISSION
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Target mode frequencies are calculated for a defined filter component used as a reference for filter components to be tuned. The defined filter component has resonant mode(s), each having a mode frequency which can be tuned to a corresponding target mode frequency via physical adjustment of parameter(s) of the filter component. A tuning equation is formed by linearly relating, via a slope matrix, changes in the mode frequencies to corresponding physical adjustment in the parameter(s), and by using an inverse of the slope matrix as part of the tuning equation. A tuning procedure is performed for a filter component to be tuned, comprising: determining, using the tuning equation, adjustment information for parameter(s) of the filter component to adjust measured mode frequency(ies) of the filter component toward meeting corresponding target mode frequency(ies) for the resonant mode(s) within corresponding tolerance(s); and outputting the determined adjustment information for physical adjustment of the parameter(s).

## Claims

### Claim 1

A method, comprising:
calculating one or more target mode frequencies for a defined filter component used as a reference for filter components to be subsequently tuned, wherein the defined filter component has one or more resonant modes, each of which has a mode frequency which can be tuned to a corresponding target mode frequency via physical adjustment of one or more parameters associated with the defined filter component;
forming a tuning equation at least by linearly relating, via a slope matrix, changes in one or more mode frequencies to corresponding physical adjustment in the one or more parameters, and wherein the tuning equation relates physical adjustment in the one or more parameters to changes in the one or more mode frequencies adjusted by an inverse of the slope matrix; and
for a filter component to be tuned, performing a tuning procedure comprising:
determining, using at least the tuning equation, adjustment information for at least one of the one or more parameters of the filter component to be tuned to adjust each of one or more measured mode frequencies of the filter component to be tuned toward meeting a corresponding target mode frequency for a corresponding resonant mode within a corresponding tolerance; and
outputting the determined adjustment information for the at least one parameter to be used for physical adjustment of the at least one parameter.

### Claim 2 (depends on 1)

The method of claim 1, wherein the tuning procedure further comprises:
performing the physical adjustment of the at least one parameter.

### Claim 3 (depends on 2)

The method of claim 2, comprising performing the tuning procedure to physically adjust parameters of the filter component to be tuned until a tuned version of the filter component to be tuned has each one of a set of the one or more measured mode frequencies meeting the corresponding target mode frequency for the corresponding resonant mode within the corresponding tolerance.

### Claim 4 (depends on 3)

The method of claim 3, further comprising assembling the tuned filter component into a filter and placing the filter in a device.

### Claim 5 (depends on 1)

The method of claim 1, wherein:
at least one of the one or more parameters corresponds to physical adjustments that are reversible;
the defined filter component has a defined physical structure with the at least one parameter corresponding to these physical adjustments having design dimensions; and
the filter component to be tuned has been manufactured with the defined physical structure and the corresponding design dimensions.

### Claim 6 (depends on 5)

The method of claim 5, wherein the defined physical structure comprises a parameter of a tuning screw, and wherein the tuning screw for the filter component to be tuned is partially inserted into the filter component to be tuned, and the partial insertion of the screw creates a design dimension for the insertion.

### Claim 7 (depends on 5)

The method of claim 5, wherein:
the at least one of the one or more parameters is at least one first parameter;
the at least one first parameter corresponds to physical adjustments that are reversible;
at least one second parameter of the one or more parameters corresponds to physical adjustments that are not reversible;
the defined filter component has a defined physical structure with the at least one second parameter corresponding to these physical adjustments having design dimensions; and
the filter component to be tuned has been manufactured with the defined physical structure but with one or more dimensions that are modified from the corresponding design dimensions.

### Claim 8 (depends on 1)

The method of claim 1, wherein:
at least one of the one or more parameters correspond to physical adjustments that are irreversible;
the defined filter component has a defined physical structure with the at least one parameter corresponding to these physical adjustments having design dimensions; and
the filter component to be tuned has been manufactured with the defined physical structure but with one or more dimensions that are modified from the corresponding design dimensions to cause adjustment that is opposite to adjustment which will occur during irreversible physical adjustment operations.

### Claim 9 (depends on 8)

The method of claim 8, wherein the defined physical structure comprises a cube having parameters of six different faces, each set of faces being parallel along one of three different axes and having a design dimension of a distance between the set of faces, and wherein the filter component to be tuned has been manufactured with at least one dimension along a corresponding axis larger than a corresponding design dimension.

### Claim 10 (depends on 8)

The method of claim 8, wherein the defined physical structure comprises a parameter of a hole having a design dimension, and wherein the filter component to be tuned has been manufactured with a dimension of the hole that is shallower than a hole with the design dimension.

### Claim 11 (depends on 8)

The method of claim 8, wherein the defined physical structure comprises a parameter of a dented metal enclosure and wherein the filter component to be tuned has been manufactured with an un-dented metal enclosure.

### Claim 12 (depends on 1)

The method of claim 1, wherein:
calculating further comprises calculating the one or more target mode frequencies of the defined filter component including a test structure attached; and
the method further comprises measuring the one or more measured mode frequencies using a test structure attached to the filter component to be tuned.

### Claim 13 (depends on 1)

The method of claim 1, wherein:
determining the adjustment information comprises:
subtracting the one or more target mode frequencies from the one or more measured mode frequencies to obtain a vector of mode frequency errors;
calculating one or more physical adjustments in corresponding parameters required to tune the filter component to be tuned by multiplying the inverted slope matrix by the vector of mode frequency errors to create a result and negating the result; and
outputting further comprises outputting the calculated one or more physical adjustments to be used for physical adjustment of the corresponding parameters.

### Claim 14 (depends on 13)

The method of claim 13, wherein:
each of the corresponding parameter corresponds to one of a plurality of dimensions of the filter component to be tuned; and
the method further comprises physically modifying at least one of the dimensions of the filter component to be tuned, based on the calculated one or more physical adjustments that have been output.

### Claim 15 (depends on 14)

The method of claim 14, wherein the filter component to be tuned comprises a cuboid bounded by six faces, each set of two sides being disposed along a different one of three directions and separated by one of the three dimensions, the cuboid comprising ceramic having an outer surface covered with a conductive coating, and wherein physically modifying at least one of the dimensions of the filter component to be tuned comprises removing part of the ceramic from at least one face of the cuboid by an amount that is less than or equal to a value of a corresponding one of the one or more calculated adjustments, and wherein the method further comprises reapplying the conductive coating to the at least one face where the ceramic was removed.

### Claim 16 (depends on 13)

The method of claim 13, wherein:
the method further comprises selecting at least one of the dimensions of the filter component to be tuned, from one of the dimensions to all of the dimensions;
the method further comprises physically modifying the selected at least one of the dimension of the filter component to be tuned, based on the calculated one or more physical adjustments that have been output and that correspond to the selected at least one dimension, wherein the physically modifying is performed using all of an amount of the calculated one or more physical adjustments that have been output or is performed using less than all of the amount of the calculated one or more physical adjustments that have been output; and
performing the tuning procedure further comprises, after physically modifying the selected at least one of the dimension of the filter component to be tuned:
measuring the mode frequencies using a test structure attached to the filter component to be tuned;
comparing the target mode frequencies and the measured mode frequencies to determine whether each one of a set of the one or more measured mode frequencies meets a target mode frequency for a corresponding resonant mode within a corresponding tolerance.

### Claim 17 (depends on 16)

The method of claim 16, wherein the physically modifying the selected at least one of the dimensions is performed using less than all of the amount of the calculated one or more physical adjustments that have been output.

### Claim 18 (depends on 16)

The method of claim 16, wherein, in response to each one of the set of the one or more measured mode frequencies not meeting its target mode frequency for the corresponding resonant mode within the corresponding tolerance, performing the following again: determining adjustment information, outputting the determined adjustment information, selecting at least one of the dimensions of the filter component to be tuned, physically modifying the selected at least one of the dimensions of the filter component to be tuned, measuring the mode frequencies, and comparing the target mode frequencies and the measured mode frequencies.

### Claim 19 (depends on 16)

The method of claim 16, performing, in response to each of the set of the one or more measured mode frequencies meeting a target mode frequency for the corresponding resonant mode within the corresponding tolerance, stopping the method and considering the filter component to be tuned as being tuned.

### Claim 20 (depends on 16)

The method of claim 16, wherein comparing the target mode frequencies and the measured mode frequencies further comprises subtracting the target mode frequencies from the measured mode frequencies to obtain mode frequency errors and determining whether each of the mode frequency errors is within a corresponding tolerance.

### Claim 21 (depends on 1)

The method of claim 1, wherein performing the tuning procedure comprises performing the tuning procedure using the tuning equation to physically adjust at least one of the one or more parameters of the filter component to be tuned until the tuned version of the filter component to be tuned has a single measured mode frequency meeting a corresponding target mode frequency for one resonant mode within a corresponding tolerance.

### Claim 22 (depends on 1)

The method of claim 1, wherein performing the tuning procedure comprises performing the tuning procedure using the tuning equation to physically adjust at least one of the one or more parameters of the filter component to be tuned until the tuned version of the filter component to be tuned has multiple measured mode frequencies meeting corresponding multiple target mode frequencies for corresponding multiple resonant modes within corresponding multiple tolerances.

### Claim 23 (depends on 1)

The method of claim 1, wherein:
both the defined filter component and the filter component to be tuned comprise a cuboid bounded by six faces, each set of two sides along a different one of three directions x, y, and z, the cuboid comprising ceramic having an outer surface covered with a conductive coating; and
the slope matrix is a matrix of partial derivatives and relates changes in mode frequencies Δfx, Δfy, and Δfz in the x, y, and z directions, respectively, to changes in adjustable parameters ΔSx, ΔSy, and ΔSz, which are changes in the x, y, and z directions, in the parameters of dimensions in three dimensions, based on the following equation:
(
Δ
⁢
⁢
f
x
Δ
⁢
⁢
f
y
Δ
⁢
⁢
f
z
)
=
(
∂
f
x
∂
S
x
∂
f
x
∂
S
y
∂
f
x
∂
S
z
∂
f
y
∂
S
x
∂
f
y
∂
S
y
∂
f
y
∂
S
z
∂
f
z
∂
S
x
∂
f
z
∂
S
y
∂
f
z
∂
S
z
)
⁢
(
Δ
⁢
⁢
S
x
Δ
⁢
⁢
S
y
Δ
⁢
⁢
S
z
)
,
wherein
(
∂
f
x
∂
S
x
∂
f
x
∂
S
y
∂
f
x
∂
S
z
∂
f
y
∂
S
x
∂
f
y
∂
S
y
∂
f
y
∂
S
z
∂
f
z
∂
S
x
∂
f
z
∂
S
y
∂
f
z
∂
S
z
)
is the slope matrix and ∂f/∂S is a partial derivative of mode frequency f with respect to the adjustable parameter S.

### Claim 24 (depends on 1)

The method of claim 1, wherein:
both the defined filter component and the filter component to be tuned comprise a resonator with N resonant modes and a same number of physical adjustments;
the mode frequencies are denoted by the vector:
F
=
[
f
1
f
3
f
3
⋮
f
N
]
;
the adjustments are quantified by the vector:
S
=
[
s
1
s
3
s
3
⋮
s
N
]
;
a variation of frequencies with small adjustments is expressed by:
ΔF=MΔS;
a vector of adjustment changes is denoted by:
Δ
⁢
⁢
S
=
[
Δ
⁢
⁢
s
1
Δ
⁢
⁢
s
3
Δ
⁢
⁢
s
3
⋮
Δ
⁢
⁢
s
N
]
;
a vector of resultant frequency changes is denoted by:
Δ
⁢
⁢
F
=
[
Δ
⁢
⁢
f
1
Δ
⁢
⁢
f
3
Δ
⁢
⁢
f
3
⋮
Δ
⁢
⁢
f
N
]
;
and
the slope matrix composed of partial derivatives of mode frequencies with respect to adjustment parameters is denoted by:
M
=
[
∂
f
1
∂
s
1
∂
f
1
∂
s
2
∂
f
1
∂
s
3
…
∂
f
1
∂
s
N
∂
f
2
∂
s
1
∂
f
2
∂
s
2
∂
f
2
∂
s
3
…
∂
f
2
∂
s
N
∂
f
3
∂
s
1
∂
f
3
∂
s
2
∂
f
3
∂
s
3
…
∂
f
3
∂
s
N
⋮
⋮
⋮
⋱
⋮
∂
f
N
∂
s
1
∂
f
N
∂
s
2
∂
f
N
∂
s
3
…
∂
f
N
∂
s
N
]
.

### Claim 25 (depends on 1)

The method of claim 1, wherein the slope matrix is a matrix of partial derivatives and linearly relates changes in the one or more mode frequencies to corresponding changes in the one or more parameters further comprises calculating using one or more analytic equations derivatives of the one or more mode frequencies with respect to the one or more parameters, wherein the one or more analytic equations relate mode frequencies to the one or more parameters, and wherein calculating derivatives comprises assigning numbers for analytic equations to determine the actual numerical values for the derivatives.

### Claim 26 (depends on 1)

The method of claim 1, wherein the slope matrix is a matrix of partial derivatives and linearly relates changes in the one or more mode frequencies to corresponding changes in the one or more parameters, and the method further comprises:
changing each adjustment in a parameter a small amount in turn, then for each adjustment calculate new mode frequencies;
subtracting target mode frequencies from the new mode frequencies to determine frequency changes resulting from the adjustments;
dividing these changes by the dimension of the adjustments in parameters used previously to derive a finite difference approximation to the derivatives of mode frequencies with respect to the adjustment parameters; and
composing the derivatives into the slope matrix.

### Claim 27

A method, comprising:
performing a tuning procedure using a tuning equation, wherein the tuning equation has been previously formed and linearly relates, via a slope matrix, changes in one or more mode frequencies for a defined filter component to corresponding physical adjustment in one or more parameters of the defined filter component, wherein each of one or more resonant modes of the defined filter component can be tuned to a corresponding target mode frequency via physical adjustment of the one or more parameters, wherein the tuning equation relates physical adjustment in the one or more parameters to changes in the one or more mode frequencies adjusted by an inverse of the slope matrix, and where performing the tuning procedure comprises:
physically adjusting at least one of the one or more parameters of a filter component to be tuned until a tuned version of the filter component to be tuned has each of a set of one or more measured mode frequencies meeting a corresponding target frequency for a corresponding resonant mode within a corresponding tolerance.