JP2000261206A - Characteristic adjustment method for dielectric filter device, that for dielectric duplexer, and characteristic adjustment device for these dielectric filter device and duplexer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain a prescribed characteristic in a short time even in the case of a dielectric filter device where the relationship of the characteristic change to the extent of deletion in a prescribed position of a dielectric material or a conductive film is complicated. SOLUTION: Data indicating the relationship of the change of the adjustment value like a center frequency or a coupling coefficient between resonators to the extent of deletion in a prescribed position of the conductive film or the dielectric material of the dielectric filter device is preliminarily found, and the adjustment value is obtained from characteristics of the dielectric filter device as the adjustment object, and a target extent of deletion is found from this adjustment value, a target adjustment value, and preliminarily obtained relationship data to delete the conductive film or the dielectric material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting characteristics of a dielectric filter device such as a dielectric duplexer and a device for adjusting the characteristics.

[0002]

2. Description of the Related Art Conventionally, as a method for adjusting the characteristics of a dielectric filter, in a filter composed of lumped or distributed constant elements, a difference between measured vector information and a value calculated by an equivalent circuit of the filter is minimized. A device that determines the state value of the element so as to adjust the filter so that the state value matches the target value is disclosed in Japanese Patent Publication No. 7-5 / 1995.
No. 2206 discloses an ON COMPUTER AIDED TUNINGOF M that uses the target fo (resonance frequency) of the filter as the fo of the filter when tuning the resonator based on the characteristics of the reflection phase.
In ICROWAVE FILTERS IEEE Proc.ISCAS / 76, in the trimming device for electronic parts, the characteristic change with respect to the processing amount is stored, and the trimming condition is updated using the average value of the performance information that summarizes these. Are disclosed in JP-A-4-240901.

[0003]

SUMMARY OF THE INVENTION Dielectric filters have high Qo, excellent temperature characteristics, and are easy to adjust by removal processing as compared with surface acoustic wave filters and multilayer substrate type filters. Useful in applications where properties are required. However, it is difficult to apply the above-described conventional adjustment method to such a dielectric filter.

That is, the filter adjusting device is effective when the equivalent circuit of the filter is simple and clear, such as a Chebyshev basic low-pass filter. In a dielectric filter in which many elements (elements) on a circuit are affected, it is difficult to adjust the filter characteristics in a short time.

The filter adjustment method described above is a tuning method utilizing the fact that the passing phase between the resonator systems is 90 ° (180 ° in reflection phase) in the case of a normal band-pass filter BPF. Although it is effective for BPFs of the type, it is effective to use a block type dielectric filter with an attenuation pole outside the band,
If the characteristics are lost, it cannot be used as it is.

The electronic component trimming apparatus is effective in the case where the amount of processing and the amount of change can be approximately approximated by a linear expression. However, a dielectric filter formed by forming a conductive film on a dielectric block is effective. In the above, the relationship between the amount of processing and the amount of characteristic change is complicated, and cannot be dealt with simply by an approximate linear expression using an average value.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned various problems and to reduce the amount of a dielectric material or a predetermined portion of a conductive film to be removed, such as a dielectric duplexer having a conductive film formed on a dielectric block. Even in the case of a dielectric filter device having a complicated relationship of change in characteristics, a method of adjusting the characteristics of a dielectric filter device, a method of adjusting the characteristics of a dielectric duplexer, and the like, in which predetermined characteristics can be easily obtained in a short time. It is an object to provide a characteristic adjustment device.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a method for adjusting the characteristics of a dielectric filter device such as a dielectric duplexer formed by forming a conductive film on a dielectric material. A first step of previously obtaining deletion amount-to-adjustment value relationship data indicating a relationship of a change in an adjustment value such as a coupling coefficient between resonators or a center frequency with respect to a deletion amount of a predetermined portion of the conductive film or the dielectric material; The characteristic of the dielectric filter device to be adjusted is measured, the adjustment value of the dielectric filter device to be adjusted is obtained from the characteristic, the difference between the adjustment value and the target adjustment value and the deletion amount are adjusted. A second step of obtaining a target removal amount of the conductor film or the dielectric material from the value relation data and deleting the conductor film or the dielectric material of the dielectric filter device to be adjusted based on the target removal amount. Consisting of a flop.

As described above, in the first step, the relationship between the center frequency and the change in the adjustment value such as the coupling coefficient between the resonators with respect to the amount of removal of the dielectric material or the conductive film of the dielectric filter device as a sample is determined. In a second step, an adjustment value of the filter is obtained from the characteristics of the dielectric filter device to be adjusted, and the conductor film or the dielectric material is obtained from the target adjustment value and the relationship data between the deletion amount and the adjustment value. Is determined, and the conductor film or the dielectric material of the dielectric filter device is deleted based on the target deletion amount.

Further, according to the present invention, a change in the adjustment value of the dielectric filter device due to the removal of the conductor film or the dielectric material of the dielectric filter device to be adjusted is obtained, and the data on the relationship between the deletion amount and the adjustment value is corrected. I do. Thus, even if the relationship between the amount of deletion of the dielectric filter device and the adjustment value varies, the data on the relationship between the amount of deletion and the adjustment value of the dielectric filter device, which is a sample, is adjusted when the dielectric filter device to be adjusted is adjusted. The accuracy of the corrected data indicating the relationship between the change in the adjustment value and the deletion amount gradually increases.

According to the present invention, the relationship data between the deletion amount and the adjustment value is used as a coefficient of a function representing a change in the adjustment value with respect to the deletion amount. Thereby, the form of the function can be easily represented, and the data representing the relationship between the change of the adjustment value and the deletion amount can be easily corrected.

Further, the present invention provides the above-mentioned second step, wherein the amount of one removal of the conductor film or the dielectric material of the dielectric filter device in the second step is made smaller than the above-mentioned target removal amount. Is repeated several times. As a result, the adjustment is performed gradually until the target characteristic of the dielectric filter device is obtained, so that excessive shaving can be prevented.

Further, according to the present invention, an upper limit value is set for a single removal amount or a target removal amount of the conductor film or the dielectric material of the dielectric filter device in the second step. This can prevent generation of an unadjustable dielectric filter device due to excessive shaving.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for adjusting the characteristics of a single dielectric filter according to an embodiment of the present invention will be described with reference to FIGS. 1A and 1B are views showing the structure of a dielectric filter, wherein FIG. 1A is a perspective view and FIG. 1B is a cross-sectional view thereof. FIG.
In the figure, 1 is a rectangular parallelepiped dielectric block having two inner conductor forming holes 2 extending from one end face to the other end face. Inner conductors 3 are respectively formed on the inner surfaces of these inner conductor forming holes 2. Dielectric block 1
On the other five surfaces except the upper surface in the figure, the outer conductor 4
Is provided. Thus, the upper surface in the figure is an open surface (open end of the resonator), and the lower surface is a short-circuit surface (short-circuit end of the resonator).

As shown in FIG. 2B, the inner conductor forming hole 2 is a so-called step hole having an inner diameter different between the open surface side and the short-circuit surface side.

FIG. 2 is an equivalent circuit diagram of the dielectric filter shown in FIG. Where Ze is the even mode impedance of the resonator, Zk is the coupling impedance, θ is the electrical angle at the center frequency of the filter, Cs is the stray capacitance at the open end, C
e is the coupling capacity with the outside.

In FIG. 1A, p1 and p2 are deletion portions at the time of characteristic adjustment. Here, the inner conductor is deleted together with the dielectric material portion at a constant width in the axial direction of the inner conductor forming hole, and the amount of deletion is changed depending on the axial length of the inner conductor forming hole.

FIG. 3 is a block diagram showing the configuration of the entire device for adjusting the characteristics of the dielectric filter. Here, the dielectric filter DUT is a dielectric filter having the structure shown in FIG. 1 and is attached to a measuring jig. The network analyzer measures S parameters (pass characteristics and reflection characteristics) of the dielectric filter DUT. The control device includes an arithmetic device, a storage device, an output device, and an input device. For example, the control device includes a microcomputer having an input / output port. The deletion device deletes a predetermined deletion portion of the dielectric filter DUT by a predetermined amount based on control data provided from the control device.

Here, as the adjustment value of the dielectric filter, the center frequency fo of the pass band and the coupling coefficient k between the resonators are used. The center frequency fo and the coupling coefficient k are obtained from the equivalent circuit shown in FIG. That is, the network analyzer shown in FIG. 3 measures the S parameters (S11, S12, S21, S22) of the dielectric filter in a predetermined frequency band, and the control device obtains the center frequency fo and the coupling coefficient k from these values. .

As a method for obtaining a center frequency, a coupling coefficient, and the like from S parameters, for example, Measurements of
Intercavity Coupling The method shown in IEEE MTT pp.519-523 1975.6 is used.

FIG. 4 shows two adjustment points p1, p1 shown in FIG.
The relationship between the deletion amount at p2 and the change in the adjustment value is shown. (A) is the difference df between the center frequency fo and the target value,
The relationship between the deletion point p1 required for the df to become 0 and the target deletion amount L1 is shown. (B) shows the relationship between the difference dk from the target value of the coupling coefficient k and the target deletion amount L1 of the deletion point p1 required for the dk to become zero. Similarly, (C) shows the relationship between the difference df between the center frequency fo and the target value and the target deletion amount L2 of the deletion point p2 required for the df to become zero. (D) shows the relationship between the difference dk between the coupling coefficient k and the target value and the target deletion amount L2 of the deletion part p2 required for the dk to become zero.

The above df and fk are represented by the following equations.

For the deletion point p1, df = A1 · L1 ^{1 / B1} dk = A3 · L1 ^{1 / B3 For the} deletion point p2, df = A2 · L2 ^{1 / B2} dk = A4 · L2 ^{1 / B4} This is the deletion amount L1. , L2, L1 = (df / A1) ^B1 L1 = (dk / A3) ^B3 L2 = (df / A2) ^B2 L2 = (dk / A4) ^B4 Further, A1, A2, A3, A4, B1, B2,
Since B3 and B4 are constants, L1 = A1'df ^B1 (1) L1 = A3'dk ^B3 (2) L2 = A2'df ^B2 (3) L2 = A4'dk ^B4 (4) Can be expressed by the following equation.

Therefore, the center frequency is changed by df,
And a deleted portion p for changing the coupling coefficient by dk
1 required deletion amount L1 and required deletion amount L2 of deletion location p2
And determined as ^{L1 = A1'df B1 + A3'dk B3 L2} = A2'df B2 + A4'dk B4.

However, since L1 and L2 are estimated values, there is a possibility that if L1 and L2 are deleted at one time, they will be cut too much. Therefore, when L1 and L2 become values exceeding a predetermined maximum value, the maximum value is set to L
1, L2. Also, as shown in the following equation, L1, L2
Is multiplied by constant coefficients X and Y of less than 1.0, and the value is defined as a cutting amount for one time.

L1 ′ = X · A1′df ^B1 + YA · 3′dk ^B3 (5) L2 ′ = X · A2′df ^B2 + YA · 4′dk ^B4 (6) Next, a specific characteristic adjustment method Will be described with reference to FIGS. 5 and 6. First, the first step of obtaining the relationship data between the deletion amount and the adjustment value is performed according to the procedure shown in FIG. First, the filter characteristics (S parameters in a predetermined frequency band) of a dielectric filter as a sample (the dielectric filter before deletion of p1 and p2 shown in FIG. 1) are measured by a network analyzer. Subsequently, the center frequency fo of the pass band and the coupling coefficient k between the resonators are obtained based on the S parameter.

Thereafter, the deleted portion p1 is deleted by a fixed amount, the filter characteristics are measured again, and the center frequency fo and the coupling coefficient k are obtained. Then, a change df in the center frequency and a change dk in the coupling coefficient with respect to the current deletion amount are calculated. That is, fo, k before deletion is replaced by fo, k
Find the amount of change to.

Next, a fixed amount is similarly deleted from the deleted portion p2, the filter characteristics are measured, fo and k are obtained, and d for the deleted amount at the deleted portion p2 is calculated.
Calculate f and dk. That is, fo, k before deletion of p2
, The amount of change to fo, k due to the current deletion is obtained.

The above-described deletion of a predetermined amount at the deletion points p1 and p2 and the calculation of the values of df and dk are repeatedly executed a predetermined number of times. As a result, the relationship data of the deletion amount and the adjustment value shown in FIG. 4 is obtained, and these relationships are expressed by the equations (1) to
The coefficient A in equations (1) to (4) when approximated by the equation shown in (4)
1 'to A4' and B1 to B4 are obtained.

Next, a second step for adjusting the characteristics of the dielectric filter to be actually adjusted is performed according to the procedure shown in FIG. First, the characteristics of the dielectric filter to be adjusted are measured. If the measured value is within the specified value, subsequent characteristic adjustment is unnecessary, and the characteristic adjustment is completed as it is. If it is not within the specified value, f is calculated from the S parameter in the measured predetermined frequency band.
o and k are obtained, and respective differences between the target center frequency and the coupling coefficient are obtained as df and dk. And this is the formula
(5) Substitute in (6) to calculate the deletion amount L1 of the deletion point p1 and the deletion amount L2 of the deletion point p2. Then, deletion is actually performed by the amount of the deletion.

Thereafter, the S-parameters are measured again. If the S-parameters are within the specified values, the subsequent processing is not performed and the characteristic adjustment is completed. If not within the specified value, fo, k is obtained again,
The relation data between the deletion amount and the adjustment value is corrected. That is, if the relationship between the deletion amount and the adjustment value obtained in step 1 is correctly applied to the dielectric filter being adjusted in step 2, it is not necessary to change the relationship data between the deletion amount and the adjustment value. Difference d between the target value of fo and k for the amount of deletion
In some cases, the relationship between f and dk deviates from the curve shown in FIG. In this case, differences df and dk between the target value of fo and k with respect to the current deletion amount are calculated, and the relationship data between the deletion amount and the adjustment value already obtained is corrected (complemented). Then, coefficients A1 'to A4' and B1 to B4 of a function representing a change curve of the adjustment value with respect to the deletion amount are newly obtained.

Thereafter, the target center frequency and the current f
difference df from o, target coupling coefficient and current coupling coefficient k
Is substituted into the equations (5) and (6) to calculate the deletion amounts L1 and L2, and delete them. Thereafter, this process is repeated to sequentially bring the center frequency and the coupling coefficient closer to the target value. As a result, df, dk, L1 'and L2' gradually become smaller. Then, as a result of the characteristic measurement after the deletion, when the S parameter falls within the specified value, the characteristic adjustment ends.

In the above description, for ease of explanation and understanding, the center frequency fo and the coupling coefficient k are adjusted values by taking a band-pass filter in which two resonators are coupled as an example. When three or more resonators are used, the coupling coefficient becomes plural. Further, the adjustment capacitance also includes the coupling capacitance with the external coupling electrode.

In the above-described embodiment, a single dielectric filter has been described as an example. However, a conductor film is formed on a single dielectric material such as the dielectric block, and two sets of dielectric filters are formed. The present invention can be similarly applied to the configured dielectric duplexer. That is, in the case of a dielectric duplexer, the characteristics of the transmission filter and the characteristics of the reception filter may be adjusted. Further, the branch characteristic at the antenna port portion may be used as the adjustment value. Thereby, the sneak of the transmission signal to the reception filter and the sneak of the reception signal to the transmission filter were sufficiently suppressed.
A dielectric duplexer having good branch characteristics can be easily obtained.

[0035]

According to the first, sixth, seventh and eighth aspects of the present invention, an adjustment amount such as a center frequency and a coupling coefficient for determining the characteristic is determined from the filter characteristic of a dielectric filter device such as a dielectric duplexer. Since the amount of deletion required for the adjustment amount to reach the target value can be obtained, many adjustment amounts such as the center frequency and the coupling coefficient are affected by the deletion of a certain deletion portion. In such a dielectric filter device such as a dielectric duplexer, the characteristics can be automatically and efficiently adjusted in a short time.

According to the second aspect of the present invention, even if the relationship between the amount of deletion of the dielectric filter device and the adjustment value varies, the data on the relationship between the amount of deletion and the adjustment value of the dielectric filter device as a sample is obtained by: The accuracy is corrected during the adjustment of the dielectric filter device to be adjusted, and the accuracy of the data indicating the relationship of the change of the adjustment value to the amount of deletion gradually increases.

According to the third aspect of the present invention, the form of the function can be simply represented, and the correction of the data representing the relationship of the change of the adjustment value with respect to the deletion amount is also facilitated.

According to the fourth aspect of the invention, the adjustment is gradually performed until the target characteristic of the dielectric filter device is obtained, so that excessive cutting can be prevented.

According to the fifth aspect of the present invention, it is possible to prevent generation of an unadjustable dielectric filter device due to excessive shaving.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of a dielectric filter according to an embodiment.

FIG. 2 is an equivalent circuit diagram of the dielectric filter.

FIG. 3 is a block diagram showing a configuration of a characteristic adjustment device for a dielectric filter.

FIG. 4 is a diagram showing a relationship between a deletion amount and an adjustment value.

FIG. 5 is a flowchart showing the procedure of a method for adjusting the characteristics of a dielectric filter.

FIG. 6 is a flowchart showing a procedure of a method for adjusting the characteristics of a dielectric filter.

[Explanation of symbols]

 1-dielectric block 2-inner conductor forming hole 3-inner conductor 4-outer conductor p1, p2-deleted part

Claims (8)

[Claims] 1. A method for adjusting a characteristic of a dielectric filter device comprising a dielectric material and a conductive film formed thereon, wherein a predetermined amount of the conductive film or the dielectric material of the dielectric filter device as a specimen is removed. A first step of previously obtaining deletion amount-adjustment value relation data indicating a relation of a change in an adjustment value such as a coupling coefficient between resonators or a center frequency, and measuring characteristics of a dielectric filter device to be adjusted. Calculating the adjustment value of the dielectric filter device to be adjusted from the characteristic, and calculating the difference between the adjustment value and the target adjustment value and the deletion amount versus adjustment value relation data from the conductor film or the dielectric material. A second step of obtaining a target deletion amount and deleting the conductive film or the dielectric material of the dielectric filter device to be adjusted based on the target deletion amount. 2. A change in an adjustment value of the dielectric filter device due to deletion of a conductive film or a dielectric material of the dielectric filter device to be adjusted, and correcting the deletion amount-adjustment value relation data. The method for adjusting the characteristics of a dielectric filter device according to claim 1, wherein: 3. The characteristic adjustment method for a dielectric filter device according to claim 1, wherein the deletion amount-adjustment value relation data is a coefficient of a function representing a change in the adjustment value with respect to the deletion amount. 4. The method according to claim 1, wherein the amount of the conductive film or the dielectric material of the dielectric filter device in the second step at one time is smaller than the target amount of the removal. 4. The characteristic adjusting method for a dielectric filter device according to claim 1, wherein the method is repeated. 5. The method according to claim 1, wherein an upper limit value is set for a single removal amount or the target removal amount of the conductive film or the dielectric material of the dielectric filter device in the second step. 5. The characteristic adjusting method of the dielectric filter device according to any one of 4. 6. A method for adjusting the characteristics of a dielectric duplexer, wherein the dielectric filter device according to claim 1 is a dielectric duplexer. 7. An adjusting device for adjusting a characteristic of a dielectric filter device formed by forming a conductive film on a dielectric material by deleting a predetermined portion of the conductive film or the dielectric material, wherein the sample is a sample. Means for previously obtaining deletion amount-adjustment value relationship data indicating a relationship between a center frequency and a change in an adjustment value such as a coupling coefficient between resonators with respect to the deletion amount of the predetermined portion of the dielectric filter device; and a dielectric to be adjusted. The characteristic of the filter device is measured, the adjustment value of the dielectric filter device to be adjusted is obtained from the characteristic, and the difference between the adjustment value and the target adjustment value and the deletion amount versus adjustment value relation data are used to calculate the conductor value. A target removing amount of the film or the dielectric material, and a means for removing the conductive film or the dielectric material of the dielectric filter device to be adjusted based on the target removing amount. Adjusting device. 8. A characteristic adjusting device for a dielectric duplexer, wherein the dielectric filter device according to claim 7 is a dielectric duplexer.