JPH02235411A - Voltage controlled oscillator - Google Patents

Abstract

PURPOSE:To eliminate the need for a sliding turning part, to simplify the part, to realize the oscillator simply with low cost and to improve the reliability of a voltage controlled oscillator by forming an oscillation capacitor for the voltage controlled oscillator used for a synthesizer oscillator with a variable capacitor and a chip capacitor and forming a resonance inductor with a tri-plate line. CONSTITUTION:Both faces of a ring shaped tri-plate split ring resonator 1 made of a good conductor in a voltage controlled oscillator are sandwiched with an insulation dielectric layer 8 of a glass epoxy printed circuit board or the like, and ground electrodes 6, 7 made of copper foil or the like are provided to the outside of the layer 8. Various sizes of slits 5 are provided to one side of the electrodes 6, 7, a lead wire is led to one side through ha throughhole 2 provided across the resonator 1, a variable capacitor 3 and chip capacitors 4 are connected in series with the lead wire to form a voltage controlled oscillator. The inductance is increased by removing the electrode foil so as to form a thin neck in an island shape with various shapes with the slits 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application The present invention relates to a voltage controlled oscillator used in a high frequency synthesizer oscillator for car telephones and MCA radios.

2. Description of the Related Art A conventional general frequency adjustment method for a voltage controlled oscillator is shown in FIG. Reference numeral 9 designates a tri-plate split ring resonator having a ring-shaped electrode sandwiched between dielectric layers and having ground potential metal plates on both sides thereof. Through poles 1 are connected to both ends of this tri-plate split ring resonator 9.
2, provide a lead wire to both sides of the ground on one side and varicap 10
and trimmer capacitor 1l are connected in series.

An internal triplate split ring resonator 9, an external varicap 10, and a trimmer capacitor 11 form a resonant circuit to form a voltage mQ controlled oscillator.

Problems to be Solved by the Invention In the conventional configuration described above, the trimmer capacitor 1L is used to adjust and absorb frequency variations due to component variations after assembly.
This is done by adjusting the

Since the trimmer capacitor 11 has a rotating mechanism, its cost is high, and its stability against vibrations and the like is not sufficient. In addition, since the trimmer capacitor l1 has a rotating mechanism, if the electrode lead wire becomes long or the contact resistance of the rotating sliding part becomes high frequency (approximately I GHz), it cannot be ignored. Not obtained.

Also, in the combination of inductance and capacitor of the triplate split resonator 9, if the capacitance of the capacitor, that is, the trimmer capacitor 11 is changed, the ratio of the total resonant capacitance to the capacitance of the varicap 10 will change, and the capacitance of the varicap 10 will change. There was a problem in that the ratio of DC voltage to oscillation frequency applied to change the oscillation frequency, that is, the vT sensitivity, changed, causing characteristics other than frequency to vary.

As a solution to the above problems, the present invention eliminates the trimmer capacitor and variably adjusts the inductance value using a simple method.
The present invention provides a voltage controlled oscillator with high stability and high accuracy at low cost.

Means for Solving the Problems In order to solve the above problems, the present invention uses a fixed capacitance as the resonant capacitance using a varicap and a chip capacitor, and provides a slit in advance in the ground electrode of the triplate split ring resonator to eliminate frequency variations. Accordingly, the inductance value is adjusted to remove the sun caused by the slit.

Function As mentioned above, the resonant capacitance is formed by a varicap capacitor, and the inductance of the triplate split ring resonator forming the resonant inductance is changed by cutting off the ground electrode foil, and as a result, the frequency of the resonator is changed. This is to adjust variations.

Generally, in a triplate line, the electromagnetic field distribution between the conductive electrode provided in the dielectric layer and the ground electrodes provided on both sides is uniform, but it is possible that one or both of the ground electrodes may have a defect. The impedance of the triplate line changes due to deviation from the pattern, that is, the change in impedance changes the resonance frequency as a change in inductance. Utilizing the properties of this triplate line, the resonance frequency can be changed by providing slits of different shapes and sizes in the ground electrode foil on or near the electrodes of the split ring resonator, and by cutting out a portion of this ground electrode. Can be done. For the above reasons, the resonant inductance can be adjusted by using a solid resonant chip capacitor with a constant capacity without using mechanical parts such as trimmer capacitors, resulting in low cost, high reliability, and less variation in frequency and V-sensitivity. It becomes possible to realize a highly accurate voltage controlled oscillator.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIGS. 1(a) and 1(b) are a plan view and a partial sectional view taken along the line A-A in one embodiment of the present invention. A ring-shaped tri-plate split ring resonator l made of a good conductor such as copper foil is sandwiched between two insulating dielectric layers 8 such as a glass epoxy printed circuit board on both sides. Earth electrodes 6 and 7 made of steel foil or the like are provided on the outside thereof. This earth electrode6.
Slits 5 of various sizes are provided on one side of 7. Further, a lead line is provided on one side by through holes 2 provided at both ends of the ring-shaped triplate split ring resonator 1, and a varicap 3 and a chip capacitor 4 are connected in series to form a voltage controlled resonator. It consists of

The inductance is increased by removing all or part of the ground electrode foil from the tapered necks of the islands of various sizes formed by the slits 5.

Different frequencies can be arbitrarily changed by cutting off one or more electrode foils in the island shape. This island-shaped foil may be cut off entirely, or only the neck portion may be cut off. At this time, both methods lower the resonant frequency.

The frequency can be varied at any position of the slit 5 on or near the upper surface of the foil of the triplate split ring resonator 1. A similar effect can be obtained by removing the foil from the ground electrode 7 on the other side.

FIG. 2 is a diagram of a modified Kolbitz type oscillation circuit using this triple plate split ring resonator.

Effects of the Invention In the present invention as described above, the resonant capacitance is formed by a varicap and a chip capacitor, and the resonant inductance is formed by a triplate line, so there are no sliding and rotating parts, so the component parts are simple and low cost is achieved. A highly reliable voltage-dead resonator can be obtained.

In addition, in order to easily adjust the resonant inductance with simple processing, the resonator capacitance value, which is one element of the resonator, can be a capacitor with a fixed value, so the vT sensitivity can also be set arbitrarily, and its variation is small, allowing for highly accurate voltage control. An oscillator can be realized.

As described above, the present invention has many advantages and is of great industrial value.

[Brief explanation of the drawing]

FIG. 1(a) is a plan view of a voltage controlled oscillator according to an embodiment of the present invention, FIG. 1(b) is a sectional view taken along line A-A in FIG. 1(a), and FIG. Oscillation circuit diagram, FIG. 3 is a plan view showing the configuration of a conventional voltage controlled oscillator. 1...Tri-plate split ring resonator,
2...Through hole, 3...Varicap, 4...Dip capacitor, 5...
・Slit, 6, 7... Earth electrode, 8...
...Dielectric material. Name of agent: Patent attorney Shigetaka Awano and one other person Figure 3

Claims (1)

[Claims] Both ends of the ring-shaped conductor foil are short-circuited with a capacitor such as a varicap, sandwiched from both sides between two dielectric substrates several times thicker than the ring-shaped conductor foil, and ground potential foils are bonded to both outer sides. Using a triplate type split ring resonator, several slits are provided in the ground electrode foil on one or both sides near the ring-shaped conductor foil, and the ground electrode foil is partially cut along the slits to generate oscillation. A voltage controlled oscillator that changes the frequency and adjusts it to the desired value.