JPH02215205A - Voltage controlled oscillator - Google Patents

Abstract

PURPOSE:To decrease the oscillating frequency deviation when an oscillated frequency control voltage is kept constant and to obtain modulation uniformity stably by mounting a dielectric coaxial resonator to a prescribed position directly through a notch or a throughhole provided to an insulation base. CONSTITUTION:A notch 7 or a throughhole 6 is provided at a part on a ceramic base 2 on which a dielectric coaxial resonator 1 is mounted. The dielectric coaxial resonator 1 is fitted to a metallic plate 3 together with the ceramic base 2 via the notch 7 or throughhole 6. Thus, the fluctuation of the position is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin voltage controlled oscillator in which deviations in oscillation frequency and modulation sensitivity in the voltage controlled oscillator are reduced.

[Conventional technology]

The structure of a conventional voltage controlled oscillator is described in 1. "Design and Implementation of High-Frequency Circuits" by Yukihiko Miyamoto, published by Japan Broadcast Press Association, pp. 152.
156, a dielectric coaxial resonator was mounted with other electronic components on an insulating substrate with conductors deposited thereon. Therefore, due to positional variations in mounting the dielectric coaxial resonator on the insulating substrate, when the oscillation frequency control voltage of the voltage controlled oscillator is held constant, the oscillation frequency deviation and the modulation sensitivity deviation at each oscillation frequency are large. It had become.

[Problem to be solved by the invention]

In the above conventional technology, when one oscillation frequency control voltage is kept constant in a voltage controlled oscillator after electronic components are mounted, variations in the electrical characteristics of the electronic components used, the width, length, and thickness of the conductive pattern, or the The premise is that the oscillation frequency is adjusted to obtain the desired oscillation frequency by absorbing oscillation frequency deviations caused by changes in the mounting position of components and the amount of solder for mounting electronic components.

However, in general, the oscillation frequency adjustment performed by changing the inductance component or capacitance component provided in series or parallel in the oscillation circuit has the effect of
Changes in modulation sensitivity at each oscillation frequency are not considered, and uniformity in modulation sensitivity is particularly required in the oscillation frequency band used. There have been problems with the use of direct modulation methods in modulation circuits.

In a conventional voltage controlled oscillator as shown in FIG. 2, each electronic component including a dielectric coaxial resonator 1 is fixed onto a conductive pattern formed on the surface of a ceramic substrate 2 by solder welding or the like. was.

An example of the oscillation circuit of the voltage controlled oscillator is shown in FIG. 3, after each electronic component is mounted.

When the oscillation frequency control voltage applied to the oscillation frequency control terminal 10 is kept constant, the variation in the oscillation frequency is due to the constant deviation of each electronic component, including the capacitance value deviation of the capacitor around the oscillation transistor 4.

Furthermore, the amount of solder and component attachment are affected by deviations in the amount of inductance, including the conductive pattern, and the amount of capacitance caused by positional fluctuations. Therefore, in the oscillation circuit shown in FIG. 3 as an example, the constant deviation of the elements in particular contributes greatly to the amount of variation in the oscillation frequency. However, on the other hand, the oscillation frequency fluctuations caused by positional changes in the mounting of parts were not taken into consideration because the oscillation frequency was to be adjusted. However, for voltage controlled oscillators for direct modulation circuits that require uniform modulation sensitivity in the oscillation frequency band used, the above oscillation frequency adjustment, which varies the modulation sensitivity at each oscillation frequency at the same time as the oscillation frequency, is not suitable. Naturally, sufficient consideration had to be given to the location of the electronic components.

Here, the effect of mounting positional deviation of the dielectric coaxial resonator 1 on the oscillation frequency will be explained. The conductive pattern around the dielectric coaxial resonator 1 shown in FIG. 3 and an example of mounting each electronic component are shown in FIG.
Both show conductive patterns. Dielectric coaxial resonator 1
When the conductive pattern from to the coupling capacitor C2 of the oscillation transistor 4 is isometrically Ll, and the conductive pattern from the variable capacitance diode 5 to the DC cutoff capacitor C1 is isometrically L2, the above dielectric As shown in FIG. 5, when the body coaxial resonator 1 is installed in a state shifted from FIG. It can be easily inferred that frequency fluctuations occur.

The object of the present invention is that variations in the mounting position have the greatest effect on the oscillation frequency deviation. The mounting of the dielectric coaxial resonator of the above-mentioned conventional technology reduces the oscillation frequency deviation when the oscillation frequency control voltage is kept constant by suppressing variations in position.
Another object of the present invention is to obtain a voltage controlled oscillator that can stably obtain modulation sensitivity uniformity in the used oscillation frequency band.

[Means for solving division problems]

In order to achieve the above purpose, a dielectric coaxial resonator, which is one of the electronic components constituting a voltage controlled oscillator, is not fixed to an insulating substrate on which a conductive pattern is formed on one surface, but a through hole is provided in the insulating substrate. The dielectric coaxial resonator is directly attached to a conductive plate that can be electrically and mechanically fixed to the ground conductor on the back surface of the insulating substrate along the hole or notch.

[For production]

The through hole or notch provided in the insulating substrate for mounting the dielectric coaxial resonator has the role of accurately mounting the dielectric coaxial resonator in a predetermined position.

In order to equalize the inductance and capacitance components, including the conductive pattern between the dielectric coaxial resonator and other electronic components, which conventionally varied depending on the position, the oscillation frequency control voltage is kept constant. The deviation of the oscillation frequency and the deviation of the modulation sensitivity within the used oscillation frequency band will be reduced.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

1(a) and (b) are external views showing an embodiment of a voltage controlled oscillator according to the present invention, FIG. 2 is an external view of a conventional voltage controlled oscillator, and FIG. 3 is a diagram showing an example of an oscillation circuit. FIG. 4 is a diagram showing an example of mounting the conductive pattern and electronic components on the ceramic substrate by the oscillation circuit, FIG. 5 is a diagram showing another example of mounting the conductive pattern and electronic components on the ceramic substrate. 7 is a diagram showing an example of mounting a conductive pattern and electronic components when a through hole is provided in the ceramic substrate, FIG. 7 is a diagram showing an example of mounting a conductive pattern and electronic components when a notch is made in the ceramic substrate, and FIG. 1 is a sectional view of a voltage controlled oscillator covered with a conductive cover, in which (a) shows a conventional example and (b) shows an example of the present invention.

As described above, the voltage controlled oscillator of the present invention shown in FIG.
The conductive pattern up to the coupling capacitor C2 of the variable capacitance diode 5 (Figure 3) is isometrically defined as Ll, and the conductive pattern up to the DC cutoff capacitor c1 of the variable capacitance diode 5 (Figure 3) is isometrically defined as L2. In order to suppress the amount of inductance change, reduce the oscillation frequency deviation and modulation sensitivity deviation, and eliminate the need for oscillation frequency adjustment, the dielectric coaxial resonator 1 is mounted using a through hole 6 and a notch 7. The states provided on the ceramic substrate 2 are shown in (a) and (b), respectively.

Next, the operating principle of the voltage controlled oscillator with the above-mentioned through holes or notches will be explained. FIG. 6 shows an example in which a through hole 6 is provided in a portion of the ceramic substrate 2 on which the dielectric coaxial resonator 1 is mounted, and FIG. 7 shows an example in which a notch 7 is provided. Note that the shape of the conductive pattern and the mounting position of each electronic component are the same as those shown in FIG. 4 in order to facilitate comparison with conventional mounting examples. Here, when the dielectric coaxial resonator 1 is attached to a conductive plate, such as a scrap metal plate 3, together with the ceramic substrate 2 through the through hole 6, the positional fluctuation of the dielectric coaxial resonator 1 is caused by the ceramic substrate 2. The through hole 6 of the substrate 2 serves as a guide, and the number of holes can be significantly reduced compared to the conventional method. Similarly, in the case of a notch, on one side of the notch 7,
A similar result can be obtained by aligning the dielectric coaxial resonator 1. Note that the ground of the dielectric coaxial resonator 1 and the ground of other electronic circuits, which were conventionally connected by a conductive pattern on the ceramic substrate 2, are connected to the ground of the ceramic substrate 2 in the case of this embodiment.
There is no problem as long as the grounding through hole 8 is provided in the grounding hole 8 and the grounding of the dielectric coaxial resonator 1 is coupled via the metal plate 3.

As described above, according to this embodiment, the mounting of the dielectric coaxial resonator 1 can reduce deviations in oscillation frequency and modulation sensitivity caused by positional fluctuations. In addition, by directly electrically and mechanically fixing the ground conductor of the dielectric coaxial resonator 1 to a conductive plate such as a metal plate, it is possible to connect the ground conductor on the back side of the ceramic substrate, which serves as the ground for low-level electronic circuits. The impedance can be lowered, making it possible to obtain a highly stable, high-performance voltage-controlled oscillator. This effect is particularly effective in the ultra-high frequency region of UHFHF. Furthermore, from a mechanical standpoint, the dielectric coaxial resonator 1, which has traditionally been particularly large in shape and volume among the electronic components constituting a voltage-controlled oscillator, is mounted from a ceramic substrate 2 to a metal plate 3. By moving the position, there is also the effect of reducing the height of the voltage controlled oscillator by the thickness of the ceramic substrate 2. The effects of the present invention are particularly effective in providing a small and lightweight voltage controlled oscillator. Moreover, as shown in FIGS. 8(a) and (b). When the shape and dimensions are the same as those of a conventional voltage controlled oscillator, the distance between the conductive cover 9 and the dielectric coaxial resonator 1 can be increased to prevent external influences. That is, since D2>Di, -
This also has the effect of reducing fluctuations in oscillation frequency caused by the attachment of the conductive cover 9 serving as a ground conductor within the membrane and modulation caused by vibrations of the conductive cover.

Although one embodiment of the present invention has been described above, in order to attach the dielectric coaxial resonator according to the present invention, the shape of the through hole or notch provided in the ceramic substrate and the shape of the dielectric coaxial resonator used are has no restrictions.

〔Effect of the invention〕

As described above, the voltage controlled oscillator according to the present invention includes an insulating substrate having a conductive pattern formed on the front surface and a ground conductor formed on almost the entire back surface, and an electrical conductor on the ground conductor side of the insulated substrate.・In a voltage controlled oscillator consisting of a mechanically fixed conductive plate and electronic components constituting an electric circuit on the upper surface of the insulating substrate, a dielectric coaxial resonator, which is one of the electronic components, is mounted on the insulating substrate. A through hole or spark is provided for attachment, and the dielectric coaxial resonator is electrically connected to a conductive pattern on the surface of the insulating substrate or an electrode of another electronic component, and a through hole or a spark is provided in the insulating substrate. By electrically and mechanically fixing the ground conductor on the surface of the dielectric coaxial resonator to the conductive plate together with the insulating substrate through the notch, the oscillation frequency control voltage can be controlled after mounting the electronic components. This has the effect that the oscillation frequency deviation and modulation sensitivity deviation of the voltage controlled oscillator when kept constant can be reduced, and at the same time, a thin voltage controlled oscillator can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a voltage controlled oscillator according to the present invention, in which (a) shows a case where a through hole is provided in an insulating substrate, and (b) shows a case where a notch is provided in an insulating substrate, respectively. FIG. 2 is an external view of a conventional voltage controlled oscillator, FIG. 3 is a diagram showing an example of an oscillation circuit, and FIG. 4 is a diagram showing an example of mounting a conductive pattern and electronic components on a ceramic substrate by the above-mentioned oscillation circuit.
FIG. 5 is a diagram showing another example of mounting the conductive pattern and electronic components, FIG. 6 is a diagram showing an example of mounting the conductive pattern and electronic components when through holes are provided in the ceramic substrate, and FIG. 7 is a diagram showing another example of mounting the conductive pattern and electronic components. Figure 8 is a cross-sectional view of a voltage controlled oscillator covered with a conductive cover; (a) is a conventional example;
b) is a diagram showing an example of the present invention. 1... Dielectric coaxial resonator 2... Insulating substrate 3...
Conductive plate (metal plate) 6... Through hole 7... Notch (a)
Figure 1 (b) Figure 2 Figure 3 Figure 6 Figure 7 (a) (b) Figure 8

Claims (1)

[Claims] 1. an insulating substrate having a conductive pattern deposited on its surface and a ground conductor deposited on almost the entire back surface; a conductive plate electrically and mechanically fixed to the ground conductor surface side of the insulating substrate;
In a voltage controlled oscillator comprising electronic components constituting an electric circuit on the upper surface of the insulating substrate, the insulating substrate is provided with a through hole or a notch for attaching a dielectric coaxial resonator, which is one of the electronic components, and dielectric coaxial resonator,
The conductive pattern on the surface of the insulating substrate or the electrode of another electronic component is electrically connected, and the ground conductor on the surface of the dielectric coaxial resonator is connected to the conductive pattern through the through hole or notch of the insulating substrate. A voltage controlled oscillator characterized by being electrically and mechanically fixed to an insulating board and an insulating board.