JPH0542169B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a resonator suitable for filters and oscillation elements used in a frequency range including and exceeding the UHF band.

<Prior art and its problems> Resonators used in filters, oscillation elements, etc. in the above frequency range are required to have relatively high sharpness (hereinafter referred to as Q), and such resonators Conventional examples include dielectric resonators and strip lines.

However, the former type of resonator (dielectric coaxial resonator) is relatively expensive, and when used as a filter, simply arranging them in parallel does not constitute a circuit, and requires a separate coupling means such as a capacitor. However, there were problems in that the structure was complicated and large, and the assembly work was time-consuming.

On the other hand, the latter resonator (stripline) is
When the operating frequency is low, such as the 400 MHz band, the size becomes large, and since the electrodes are formed on the entire back surface of the substrate, the number of electrode members increases, resulting in an unavoidable increase in cost.

In view of the above-mentioned problems, it is an object of the present invention to provide a useful resonator that is small, low cost, and can be coupled to each other without using a separate coupling means such as a capacitor when used as a filter. The purpose is to

<Means for Solving the Problems> The present invention has been made to achieve the above-mentioned objects, and includes capacitor electrode patterns facing each other on both the front and back surfaces of a dielectric substrate,
A capacitor is formed by these two electrode patterns and a dielectric substrate between them, and an L-shaped coil pattern connected to one end of the capacitor electrode pattern is formed on the surface of the dielectric substrate. With a coil made up of
It consists of an LC series circuit.

<Embodiment> The drawings show the external configuration of a resonator as an embodiment of the present invention, with FIG. 1 being a perspective view, FIG. 2 being a front view, FIG. 3 being a side view, and FIG. 4 being a rear view. be.

In this figure, 1 is a dielectric substrate made of, for example, FDR material, and its front surface 1a and back surface 1b each have one capacitor electrode pattern 2a, 3a.
is formed by, for example, a method such as screen printing or vapor deposition of silver paste.

The electrode patterns 2a and 3a face each other on both sides of the dielectric substrate 1, forming a capacitor C having a capacitance determined by the dielectric constant and thickness of the dielectric substrate 1, and the facing area of the capacitor electrodes.

On the other hand, the coil pattern 4a is formed only on the surface 1a, and is formed as an L-shaped linear printed coil so as to reach the end opening of the dielectric substrate 1 from one end A of the electrode pattern 2a. By widening the line width to about 1.5 to 2.0 mm, this pattern 4a can obtain a Q value of 100 or more even at high frequencies.

FIG. 5 shows an equivalent circuit of the resonator according to the present invention, and it can be seen that a capacitor C is obtained by the electrode patterns 2a and 3a, and an inductance L is obtained by the coil pattern 4a.

The dielectric substrate 1 has a relative permittivity of 80 and a thickness.
FIG. 6 shows the characteristics of a resonator made by forming the above-described patterned electrodes using electrodes with a length of 0.4 mm, a length of 8 mm, and a width of 7 mm.

The resonant frequency of this resonator is 248MHz, and the Q
The value is 124.

Note that by changing the dielectric constant and thickness of the dielectric substrate, the capacitance of the capacitor C can be changed and the resonance frequency can be changed, and an appropriate thickness can be selected in relation to the operating frequency.

Furthermore, by scraping off the electrode pattern constituting the capacitor, the resonant frequency can be finely adjusted.

<Effects> As described above, the present invention has an extremely simple structure in which capacitor electrode patterns constituting a capacitor are formed on the front and back sides of one dielectric substrate, and a coil pattern is formed only on the surface of the dielectric substrate. Thus, a resonator is obtained, and by using a dielectric substrate with a high dielectric constant, the capacitor can be made relatively small. In addition, unlike conventional dielectric coaxial resonators, the capacitance of the capacitor, which is a component of the resonator, can be changed and adjusted independently, so impedance matching can be easily achieved.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a front view of the same as above, Fig. 3 is a side view, Fig. 4 is a rear view, and Fig. 5 is an equivalent circuit of the resonator of this invention. 6 are graphs showing the characteristics of the resonator of the example. 1... Dielectric substrate, 1a... Front surface, 1a... Back surface, 2
a, 3a...electrode pattern, 4a...coil pattern, C...capacitor, L...inductance.

Claims (1)

[Claims] 1 Opposed capacitor electrode patterns are formed on both the front and back surfaces of a dielectric substrate, and a capacitor is formed by both electrode patterns and the dielectric substrate between them, and one end of the capacitor electrode pattern is formed on the surface of the dielectric substrate. A resonator characterized in that an L-shaped coil pattern connected to the capacitor and a coil formed by the coil pattern form an LC series circuit.