JPH0998002A - Lc resonator and filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate connection of an LC resonator and the outside and also the resonators themselves and to easily lead out a tap of the resonator. SOLUTION: An LC resonator on a substrate is provided with a capacitor (C) 13 that includes the plate conductors 11 and 12 forming inductance (L) and the plate electrodes 131 and 132. The electrodes 131 and 132 are connected to one of both ends of each of conductors 11 and 12 respectively. A filter consists of plural LC resonators of such constitution where the inductance of resonators are connected to each other via mutual inductance, the capacitors of resonators are connected to each other via the capacitance formed by an air gap between the flat electrodes, or the plate conductor of every resonator has an intermediate tap to change the inductance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resonator and a filter suitable for use in wireless communication equipment.

[0002]

2. Description of the Related Art Conventionally, a dielectric coaxial resonator has been used as a resonator of a filter used in a mobile phone or the like. FIG. 5 shows a perspective view of such a dielectric coaxial resonator. Further, FIG. 6 is a perspective view showing a structural example of a filter using this resonator. In FIG. 5, 51 is an inner conductor, 5
Reference numeral 2 is an outer conductor, and a space between the inner conductor 51 and the outer conductor 52 is made of ceramic. The inner conductor 51 has a hole-shaped inner surface provided at the center of an end surface of a cylindrical ceramic as shown in the drawing as a conductor surface. The resonator has open surfaces 53 at both ends. FIG. 6 shows a configuration example of a filter in which two dielectric coaxial resonators 61 and 62 and circuit matching chip capacitors 64, 65 and 66 are mounted on a base substrate 60. The outer conductors of the dielectric coaxial resonators 61 and 62 are fixed to the ground conductor of the base substrate 60, and the inner conductors 611 and 62 of the resonators are fixed.
1 is connected to the external terminal of the resonator by connecting pins 631 and 632 to the terminal.

[0003]

The conventional dielectric coaxial resonator as described above has the following problems. (1) In order to connect to the outside, a pin must be inserted into the hole in the center of the dielectric and the connection terminal must be pulled out. (2) For coupling between resonators when forming a filter,
It is necessary to attach discrete parts such as capacitors and coils to the outside of the resonator. (3) It is not possible to make taps from the middle of the resonator.

An object of the present invention is to provide an LC resonator and a filter that can be easily connected to the outside and coupled between resonators and that can easily tap out from the middle of the resonator.

[0005]

In order to achieve the above object, in the LC resonator of the present invention, an inductance (L) is formed in the resonator provided on the substrate as shown in FIG. 1, for example. It is characterized by comprising a plate-shaped conductor and a capacitor (C) having a plate electrode, and connecting the plate electrode to one end of the plate-shaped conductor. Here, the plate conductor may be a conductor foil, and the capacitor having a plate electrode may be composed of a substrate conductor and a corresponding single plate electrode.

Further, a filter of the present invention for achieving the above object is, for example, as shown in FIG.
It is assumed that a plurality of resonators are provided, and the inductances of the respective resonators are coupled to each other through mutual inductance.

Alternatively, as the filter of the present invention, for example, as shown in FIG. 3, a plurality of configurations of the above-described LC resonator of the present invention are provided, and the capacitors of the respective resonators are connected to each other via the capacitance due to the gap between the plate electrodes. It is also good to combine them.

Alternatively, as the filter of the present invention,
A plurality of LC resonators according to the present invention are provided, and the plate-shaped conductors of the respective resonators are arranged so that, for example, as shown in conductor plate inductances 41 and 42 in the circuit diagram of FIG. It may be equipped with a tap.

The LC resonator of the present invention has a structure in which a plate conductor and a plate capacitor are connected to each other by a plate electrode of the capacitor, and is formed on a substrate. Therefore, the connection with the outside is not required, and the surface mounting can be performed. Therefore, the connection with the outside and the mounting are facilitated. Further, the resonators can be easily coupled to each other, and various couplings can be easily obtained without requiring discrete components. This makes it easy to make different configurations of filters. Further, the structure in which the intermediate tap of the inductance is easy to take makes it easy to change or adjust the frequency of the filter.

[0010]

FIG. 1 shows an embodiment of the present invention.
The characteristics are shown in FIG. FIG. 1 shows an example in which two LC resonators of the present invention are used, and plate conductors of the resonators are coupled to each other through mutual inductance to form a two-stage bandpass filter (hereinafter referred to as BPF). In FIG.
Reference numeral 10 is a base substrate, 11 and 12 are conductor plates for forming an inductance, 13 is a flat plate capacitor having a ceramic as a dielectric, and is a flat plate between the surface conductor of the base substrate 10 and the flat plate electrode 131 or 132 via the ceramic. It forms a capacitor. 11 and 12 are connected to the plate electrodes 131 and 132 at their one ends, respectively, and LC together with the plate capacitors having the plate electrodes 131 and 132, respectively.
Form a resonator. Further, in FIG. 1, 11 and 12 are coupled through mutual inductance. 11 and 12 may be conductor foils. Reference numerals 14 and 15 are matching chip capacitors. In FIG. 2, the horizontal axis represents frequency, and the vertical axis represents transmission characteristics and reflection characteristics in decibels (dB). Reference numerals 21 and 22 are the pass characteristics and reflection characteristics of the BPF, respectively. The center of the horizontal axis is 1.05 GHz, and the scale is 20 MHz. As an example, the median values of the transmission and reflection characteristics are −
The characteristics substantially equal to those of the conventional one can be obtained, such as the values of 1.66 dB and -9.15 dB.

FIG. 3 shows another embodiment in which a two-stage BPF is constructed. It is the same that the BPF is formed on the base substrate by using the two LC resonators of the present invention, but in this embodiment, the two resonators are configured to be coupled via the interelectrode capacitance of the capacitor. This is different from FIG. Reference numeral 30 is a base substrate, 31 and 32 are conductor plates, 33 is a flat plate capacitor having a ceramic as a dielectric, and a flat plate electrode 331 or 332 via the surface conductor of the base substrate 30 and the ceramic.
A flat plate capacitor is formed between and. 31 and 32 are connected to the plate electrodes 331 and 332 at one end of each,
Each forms a LC resonator with a plate capacitor having plate electrodes 331 and 332. Further, in FIG. 3, the two capacitors are coupled via the capacitance due to the gap 330 between the plate electrodes 331 and 332. 31 and 32 may be conductor foils. 34 and 35 are matching chip capacitors.

FIG. 4 is a circuit diagram of another embodiment in which a variable frequency filter is formed according to the present invention. Inductance 41 by a plate-shaped conductor of the same resonator as in FIG.
42 is provided with an intermediate tap and fine adjustment coils 45 and 46 are connected to the intermediate tap, respectively, so that the resonance frequency of the resonator can be finely adjusted. Reference numerals 43 and 44 are plate capacitors as constituent elements of the resonator.

As described above, since the LC resonator of the present invention and the filter using the same have a characteristic structure consisting of flat plate-shaped components, they can be easily connected to the outside and mounted, Further, there is an advantage that various filters having different coupling between the resonators can be easily formed. Further, since the intermediate tap can be easily taken, there is an advantage that the frequency can be easily changed and adjusted.

[0014]

The present invention has the following effects. That is, (1) it is not necessary to provide connection terminals, and surface mounting can be achieved. (2) Since the type of coupling between the resonators can be changed, various filter configurations can be made. (3) The tap can be removed from the resonator. Therefore, the frequency of the filter can be easily changed and adjusted, and (a) the frequency variable filter can be used, and (b) the filter can be automatically adjusted.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a characteristic example diagram of the embodiment of FIG.

FIG. 3 is a perspective view of another embodiment of the present invention.

FIG. 4 is a perspective view of another embodiment of the present invention.

FIG. 5 is a perspective view of a conventional dielectric coaxial resonator.

FIG. 6 is a perspective view of a conventional filter using a dielectric coaxial resonator.

[Explanation of symbols]

10 ... Base substrate 11, 12 ... Conductor plate 13 ... Flat plate capacitor 131, 132 ... Flat plate electrode 14, 15 ... Chip capacitor 30 ... Base substrate 31, 32 ... Conductor plate 33 ... Flat plate capacitor 330 ... Space between electrodes of flat plate capacitor 331, 332 ... Plate electrodes 34, 35 ... Chip capacitors 41, 42 ... Conductor plate inductance 43, 44 ... Plate capacitors 45, 46 ... Fine adjustment coil

Claims (4)

[Claims] 1. A resonator provided on a substrate includes a plate-shaped conductor forming an inductance (L) and a capacitor (C) having a plate electrode, and the plate electrode is connected to one end of the plate-shaped conductor. An LC resonator having a configuration. 2. A filter having a plurality of resonators on the same substrate, comprising a plurality of configurations of the LC resonator according to claim 1, wherein among the plurality of configurations, the mutual inductances interpose mutual inductances. A filter comprising a combination. 3. A filter having a plurality of resonators on the same substrate, comprising a plurality of configurations of the LC resonator according to claim 1, wherein capacitors are arranged between plate electrodes. A filter comprising a coupling through a volume by a void. 4. A filter having a plurality of resonators on the same substrate, comprising a plurality of configurations of the LC resonator according to claim 1, wherein each plate conductor of the plurality of configurations has a variable inductance. A filter characterized by comprising a middle tap.