JPS5853201A - Conductor filter - Google Patents

Abstract

PURPOSE:To realize a miniature filter with a light weight, by having a zigzag arrangement of dielectric resonators. CONSTITUTION:Holes 3-1-3-4 are drilled to a ceramic 1 having a high dielectric constant in order to form resonators. An inner conductor 4 made of a conductor film is provided to the inner surface of each hole. At the same time, a conductor film 5 is formed by metallizing on all surfaces exclusive of the upper surface and side surfaces 20. Thus a resonator is obtained with a 1/4 wavelength with respect to the using frequency. A hole 6 for control of coupling degree is drilled between the conductors 4 of the two adjacent resonators, and a control bar which is supported by an upper cover is put into the hole 6. In addition, the metallic screws for fine adjustment of resonance frequency are set opposite to each other above the conductor 4. A resonator exciting bar is connected to a connector for input/output. In such way, the resonators are arranged zigzag. This can decrease the lengthwise measurement of a conductor filter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-stage dielectric filter for radio frequency use, and in particular, dielectric resonators constituting the filter are arranged in a zigzag pattern to reduce the size and use of the filter.

Rental radio equipment, 'F! Mobile radio equipment is of course small and light, but due to the system configuration, the number of stations is several to several tens of times the number of base stations, so many filters are used to separate radio waves. Therefore, reducing the cost of filters is also a key point in making mobile radio systems more economical.

A conventional dielectric filter with a four-stage configuration is shown in the first south.
(a) is a plan view with the top cover removed, and (b) is a cape r view on the A-A' side of figure (a).

1 is a dielectric block made of a high dielectric constant ceramic (for example, a material mainly composed of barium titanate),
It is built into a metal case 2. A hole 3 for constructing a resonator is bored in the dielectric block 1, and an inner conductor 4 made of a four-layer film is provided on the inner surface of the hole 3. A solid film 5 is also provided on all surfaces of the dielectric block 1 except for the surface and side surfaces 20 by metallization, and constitutes a resonator having a length of 1/4 for the frequency used. If a conductive film is applied to the upper surface of the dielectric block l, it becomes a 1/2 wavelength resonator. A hole 6 for adjusting the degree of coupling is made between the inner cover bodies 4, 4 of two adjacent resonators, and a support 4 is inserted into the upper cover 7 in the hole 6 for adjusting the degree of coupling.
IW##8 has been inserted. The adjustment rod 8 is made of metal or a dielectric material, and by moving it up and down, the degree of coupling between two adjacent resonators is adjusted, and the degree of coupling between two adjacent resonators is adjusted. ' Fluctuations in filter characteristics due to variations in the turtle body etc. are corrected. Within minutes”
Metal screws 9... for resonant frequency fine tuning are arranged facing above l' i: + 4..., and the left end and the outside of the right carpet resonator 1! A resonator excitation rod 13 is supplied with power and connected to the input/output connector 10. From the connector 10, the pure frequency input signal is connected to the dielectric pro, via the board 13111.
K-coupled. In this case, matching of the input impedance of the dielectric turtle filter is performed by adjusting the length of the excitation rod 13 inserted one width into the resonator excitation hole 12.

The output impedance and the output of the electric filter are also adjusted by manually adjusting the excitation rod (not shown) inserted into the resonance 5 & jb vibration hole 12 of the same machine. The output of the matched filter is output from connector lO'.

As mentioned above, a long filter with a multi-stage configuration becomes considerably longer due to the increase in the number of stages, and with this kind of filter, the air βd resonator in the lateral direction becomes larger. Also the weight? I'll join you. -Another problem is that dielectric filters are made by sintering dielectric blocks such as ceramics. As a countermeasure to this problem, efforts have been made to reduce the size and length of the dielectric filter and improve the yield.

However, when downsizing the dielectric filter, since it is made of ceramics, simply reducing the dimensions will result in stricter dimensional accuracy, as well as As the flow density increases by j'h, the Q of the filter characteristics also deteriorates, resulting in a total reduction in the performance of the filter.

The present invention does not provide this solution.

This objective is achieved by arranging the resonators in a multistage dielectric block in a zigzag manner to shorten the longitudinal dimension.

3- If there is a possibility that electromagnetic coupling may occur with other resonators other than the j4, lj'jj contacting resonators in this configuration, for example, if the connections between adjacent resonators are close, the adjacent volume resonance This can be achieved by providing a groove in which a conductive film is formed parallel to the ML'+ hole in the bolt of the vessel and making the connection loose.

In this way, the length can be reduced to the conventional characteristic of 1. The dimensional accuracy is 9, which is the conventional characteristic, without increasing the processing cost.

The gist of the present invention will be explained in detail with reference to embodiments of the present invention shown in the drawings below.

Figure 2 shows a perspective view of an example of the dielectric block of the present invention, which forms the main part of a 4-stage Jijl 'Vt five-body filter, and Figure 3 shows the T-cap 1 of the completed filter.
An r-view is shown. The conventional technique shown in FIG. 1 is applied to the top cover including the filter adjustment mechanism and the common frequency adjustment rod or screw joint adjustment rod attached to the top cover (t1).

Further, the dielectric block portion will be explained in correspondence with FIG. 1. Therefore, in FIGS. 2 and 3, the same reference numerals are used for parts having the same functions as those in FIG. 1.

Figure 2 shows a dielectric block in which the holes for each resonator were conventionally formed so that they were located on the central axis in the transverse direction of the upper surface of the dielectric block, but the holes were arranged in a zigzag pattern. . Its length t2 is naturally shorter than the conventional length 1+ (FIG. 1).

A conductive film 5 is coated on all surfaces of the dielectric block 10 except for the surface and side surfaces 20. Further, a conductor film is similarly applied to the inner surface 4 of the hole 3 of the resonator.

With the conductor film coated as described above, it is housed in the metal case 2 shown in FIG. 3, and the lead wire 11 of the connector 10 is connected to the upper surface of the input side resonator excitation hole 12. The lead wire of the output side connector 10' is similarly connected to the upper surface of the hole 12'. Then, the dielectric block and the input impedance are matched by changing the length of the excitation rod inserted into the resonator excitation hole, and when matching is achieved, they are fixed with adhesive.

Next, resonator hole 3. The screws 9 for frequent use in frequency and the rod 8 for adjusting the degree of connection attached to the top cover 7 facing the hole 6 for adjusting the degree of connection are respectively ii? j to configure a di-α-body filter.

After completion of Aoi 4 adjustment, input connector 10 with No. 9 [definition: 'i'
l: Input AjW 'I'Fj number, output terminal 10
When the transmission characteristics of this filter are measured by connecting a level meter to
Characteristics almost equivalent to iqi properties can be obtained.

On the other hand, if there is electromagnetic field interference from a third resonator other than the adjacent resonator, the relationship between the resonator and the third resonator is It is sufficient to form a 4-dimensional conductor film at the position 11't between 1' and 11't.

FIG. 4 is a perspective view of a visiting body block according to another embodiment of the present invention, which was manufactured in accordance with the above-mentioned points. In order to prevent the coupling of the 4I magnetic field from the external resonator, Ir
'8η↓2 resonator hole 3-1 formed in a zigzag shape
I'i parallel to this hole in the middle of ~3-4 = 14-1
~14-4 Apply a synthetic film to the inner surface of the entire groove.

For example, the distance t between the groove 14-2 and the opposing hole 3-2 is +11.

The hole 3-2 is formed so that the distance 1s between the hole 3-2 and the hole 3-2 has the same dimensions. That is, hole 3-2 and side (back side) 1
and the distance t4 between the groove 14-2 and the hole 3-2.
By setting t3 to t4, the diameter of the inner conductor is set to the hole 3-2, and the diameter of the outer conductor is set to the diameter of the hole 3-2 + 13 + 1. A resonator with a certain impedance is formed.

Using the dielectric block formed as described above, a dielectric filter is fabricated as shown in FIG. If configured using the same method as explained in FIG. 3, results equivalent to the filter characteristics shown in FIG. 1 can be obtained.

The present invention is not limited to the illustrated embodiments, but is
Appropriate modifications can be made within the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 shows a conventional example, FIG. 2 shows a perspective view of an embodiment of the dielectric block of the present invention, FIG. 3 shows a dielectric filter of the present invention, and FIG. 4 shows another dielectric block of the present invention. . In the figure, 1 is a dielectric block, 2 is a metal case, 3 is a hole for a 5V resonator, 4 and 5 are conductive films, 6 is a hole for adjusting the degree of coupling, 7 is a top cover, and 8 is a coupling hole. Resonance p7 is used for adjusting the vibration; byl vibration hole, 13 excitation rods, and 14 indicate grooves. 8- $1 area

Claims (2)

[Claims] (1) A dielectric block shaker is formed with a plurality of holes in a zigzag shape (at intervals of 1 mm), and a conductive film is formed on the surface of the dielectric block including the inner surface of the holes. On the other hand, a dielectric filter is characterized in that a resonator is configured with a resonant frequency based on the depth of the hole. (2) In each resonator of the dielectric block, a conductive film is densely layered on the surface between the resonators to facilitate electromagnetic field coupling with resonators other than the adjacent resonator. )
The dielectric filter according to claim 1, characterized in that a groove is formed.