JPH1146116A - Oscillator and oscillation system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the small-sized oscillator easily oscillating a signal and the oscillating system using the oscillator. SOLUTION: Relating to the oscillator 10, an oscillation transistor(TR) 11 is placed on a dielectric substrate and a 1/4 wavelength open end stub 12 connects to its base. Furthermore, a collector of the TR 11 connects to ground via a capacitor 13. Moreover, en emitter of the TR 11 connects its collector (base) via a feedback capacitor C1(C2). Since the 1/4 wavelength open end stub 12 is regarded as ground in terms of distributed constants, the oscillator 10 acts like a common base circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillator and an oscillator using the same, and more particularly to a grounded-base or gate-grounded oscillator having a quarter-wave open end stub connected to the base or gate of a transistor, and an oscillator having the same. It relates to the oscillation device used.

[0002]

2. Description of the Related Art As a conventional oscillator using a dielectric resonator, there is an oscillator having a circuit configuration as shown in FIG. The oscillator 50 shown in FIG. 7 is of a so-called band reflection type, in which an oscillation transistor 51 such as a silicon bipolar transistor is provided, for example, by a dielectric substrate (not shown).
The strip line 52 is connected to the base. A DC cut capacitor 53 and a terminating resistor 54 are sequentially connected to the strip line 52. The dielectric resonator 5 is located near the strip line 52.
5 is arranged, whereby the strip line 52 is magnetically coupled with the dielectric resonator 55. Further, the collector of the oscillation transistor 51 is grounded. The emitter of the oscillation transistor 51 is connected to a collector and a base. Here, the terminating resistor 54 is connected to the dielectric resonator 5.
It functions to remove unnecessary oscillations other than the resonance frequency of 5.
In FIG. 7, the capacitance shown between the emitter and the collector and between the emitter and the base of the oscillation transistor 51 can be replaced by the internal capacitance and the floating capacitance of the oscillation transistor 51. , Cannot be mounted as a part.

[0003]

However, in the oscillator using the above-described conventional dielectric resonator, the dielectric resonator is oscillated by resonance at a specific frequency, so that it is often used in a high frequency band. There is a problem that the size of the dielectric resonator is increased due to its large size and the necessity of a metal case for blocking magnetic flux of the dielectric resonator.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a small-sized and easy-to-oscillate oscillator and an oscillation device using the same.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an oscillation transistor, a １ ／ wavelength open-end stub connected to the base or gate of the oscillation transistor, and A capacitor connected to the collector or the drain of the transistor and having a resonance frequency lower than the oscillation frequency.

Further, a high impedance line is connected in series to the capacitor.

Further, the oscillator is magnetically coupled to a resonator comprising a stub having a 波長 wavelength short-circuit end.

According to the oscillator of the present invention, the oscillator is constituted by the oscillation transistor, the １ ／ wavelength open end stub, and the capacitor, so that the oscillator can be miniaturized.

According to the oscillation device of the present invention, since the oscillator and the resonator are resonated with each other by magnetically coupling the oscillator and the resonator, the resonator can be resonated almost without load. .

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit configuration diagram of a first embodiment of the oscillator according to the present invention. The oscillator 10 includes an oscillation transistor 11 such as a silicon bipolar transistor.
Is disposed on, for example, a dielectric substrate (not shown), and a 波長 wavelength open-end stub 12 is connected to a base thereof.

The collector of the oscillation transistor 11 is grounded via the capacitor 13. Further, the emitter of the oscillation transistor 11 is connected to the collector and the base via the feedback capacitors C1 and C2.

Since the １ ／ wavelength open end stub 12 can be regarded as ground when viewed in terms of distributed constant, this oscillator 1
0 is the base ground. The 1/4 wavelength open end stub 12 is formed of a strip line or a microstrip line.

Further, the capacitor 13 is connected to the oscillator 1
It has a resonance frequency fr lower than the oscillation frequency fo of zero. The feedback capacitances C1 and C2 between the emitter and collector and between the emitter and base of the oscillation transistor 11 are
For example, at a high frequency of about 6 GHz in which the oscillator 10 is used, a very small capacitance is sufficient. Therefore, the internal capacitance and the floating capacitance of the oscillation transistor 11 are substituted, and are not attached as components.

With the above configuration, the capacitor 13 functions as an inductance component at the resonance frequency fr or higher, and the oscillator 10 becomes a Colpitts oscillator. Therefore, the oscillator 10 starts oscillating at a frequency at which the combined reactance of the inductive reactance components of the 波長 wavelength open end stub 12 and the capacitor 13 and the capacitive reactance components of the feedback capacitors C1 and C2 becomes zero. The frequency fo is the 、 wavelength open end stub 12 and the capacitor 1
Assuming that the combined inductance with No. 3 is L, the following is obtained. 2πfo = 1 / (L (C1 + C2)) ^1/2 FIG. 2 shows the frequency characteristics of the oscillator 10. From this figure,
It can be seen that the oscillator 10 oscillates at a frequency of 5.7667 GHz.

According to the first embodiment, the oscillator comprises:
Since it is composed of a bipolar transistor or a field-effect transistor, a 波長 wavelength open-end stub, and a capacitor, the size of the oscillator can be reduced.

Further, since the capacitor has a resonance frequency lower than the oscillation frequency, the capacitor functions as an inductance component above the resonance frequency, and the oscillator becomes a Colpitts oscillator. Therefore, it is possible to easily oscillate at a frequency at which the combined inductance of the oscillator becomes zero.

FIG. 3 is a circuit diagram of a second embodiment of the oscillator according to the present invention. The oscillator 20 is different from the oscillator 10 of the first embodiment (FIG. 1) in that a high impedance line 21 is connected in series to a capacitor 13 connected between the collector of the transistor 11 and the ground.

According to the second embodiment, by adjusting the length of the high-impedance line 21, the open-ended stub 12 and the capacitor can be compared with the oscillator 10 of the first embodiment. It is easy to optimize the combined inductance of the line 13 and the high impedance line 21. Therefore, adjustment of the oscillation frequency fo of the oscillator 20 becomes easy.

FIG. 4 is a circuit diagram of an embodiment of the oscillation device according to the present invention. The oscillating device 30 includes the oscillator 10 (FIG. 1) and the resonator 31.

The resonator 31 is a stub 3 having a 波長 wavelength short-circuit end.
Consists of two. The 1/4 wavelength open end stub 12 of the oscillator 10 and the 1/4 wavelength short end stub 3 of the resonator 31
2 is magnetically coupled, so that the oscillator 10 and the resonator 31 are magnetically coupled. The 1/4 wavelength short-circuit end stub 32 is formed of a strip line or a microstrip line.

With the above configuration, the oscillator 10 and the resonator 31 are magnetically coupled to each other.
Resonate with each other. Therefore, as shown in FIG.
In the oscillation device 30, two resonance frequencies fr1 and fr2 are obtained. For comparison, the characteristics of the oscillator 10 are indicated by broken lines.

The resonance frequencies fr1 and fr2 change depending on the strength of the magnetic coupling between the oscillator 10 and the resonator 31.
The oscillation device 30 oscillates at one of the resonance frequencies fr1 and fr2. Therefore, by changing the strength of the magnetic coupling between the oscillator 10 and the resonator 31, the oscillation device 30
Oscillation frequency can be easily changed.

Further, since the oscillator 10 and the resonator 31 are magnetically coupled to each other, the oscillator 10 and the resonator 31 resonate with each other, so that the resonator 31 can resonate almost without load. As a result, Output voltage (Carrie
C / N, which is the ratio of r) to the noise voltage (Noise) near the oscillation frequency, can be improved.

That is, according to the experiment, the oscillation frequency 6G
C / N of the oscillation device 30 at -9 Hz is -90.8 dB
And -88.3 dB which is the C / N of the oscillator 10 (FIG. 1).
Is improved by 2.5 dB as compared with.

According to the third embodiment, the oscillation frequency of the oscillation device can be controlled by magnetically coupling the oscillator and the resonator and changing the strength of the magnetic coupling.

In addition, since the resonator constituting the oscillation device can resonate with almost no load, the C
/ N can be improved, and a high C / N ratio can be realized.

Further, as shown in FIG. 6, an oscillation frequency adjustment circuit 3
The stub 34 having a quarter-wavelength open end constituting the stub 3 is magnetically coupled, and the capacitance component of the oscillation frequency adjustment circuit 33 is controlled by the varactor diode VD, which is a device whose capacitance changes with voltage, so that the oscillator 10 and the resonator By controlling the strength of the magnetic coupling with the oscillator 31, the oscillation frequency can be controlled by the voltage, and the invention can be applied to a voltage-controlled oscillator.

In the first to third embodiments, the case where a bipolar transistor is used has been described. However, a similar effect can be obtained when a field effect transistor is used.

Further, in the third embodiment, one 1
Although the case where the 波長 wavelength open end stub and one １ ／ wavelength short end stub are magnetically coupled has been described, a plurality of 波長 wavelength open end stubs and a plurality of 波長 wavelength short end stubs are used, respectively. For example, they may be configured in a comb shape and magnetically coupled. In this case, the resonance frequency becomes three or more, and the stability of the oscillation frequency of the oscillator increases.

Further, a case has been described where a varactor diode is used as an element whose capacitance changes with voltage. However, the invention can be similarly applied to a voltage controlled oscillator by using a PIN diode, a transistor, or the like.

Further, even if an oscillator is formed on a material whose permittivity is variable by a voltage, the present invention can be similarly applied to a voltage controlled oscillator.

[0032]

According to the oscillator of the first aspect, the oscillator comprises:
Since the oscillation transistor, the 波長 -wavelength open end stub, and the capacitor are used, the size of the oscillator can be reduced.

Further, since the capacitor has a resonance frequency lower than the oscillation frequency, the capacitor functions as an inductance component above the resonance frequency, and the oscillator becomes a Colpitts type oscillator. Therefore, it is possible to easily oscillate at a frequency at which the combined inductance of the oscillator becomes zero.

According to the oscillator of the second aspect, since the high impedance line is connected in series to the capacitor connected between the collector of the transistor and the ground, by adjusting the length of the high impedance line, 1
It is easy to optimize the combined inductance of the 波長 wavelength open end stub, the capacitor, and the high impedance line. Therefore, the adjustment of the oscillation frequency becomes easy.

According to the oscillation device of the third aspect, the oscillation frequency of the oscillation device can be controlled by magnetically coupling the oscillator and the resonator and changing the strength of the magnetic coupling.

Further, since the resonator resonates almost without load, the C / N of the oscillation device can be improved, and the high C
/ N can be realized.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a first embodiment according to an oscillator of the present invention.

FIG. 2 is a diagram illustrating frequency characteristics of the oscillator of FIG. 1;

FIG. 3 is a circuit configuration diagram of a second embodiment according to the oscillator of the present invention.

FIG. 4 is a circuit configuration diagram of an embodiment according to the oscillation device of the present invention.

FIG. 5 is a diagram illustrating frequency characteristics of the oscillation device of FIG. 4;

FIG. 6 is a circuit configuration diagram when the oscillation device of FIG. 4 is applied to a voltage controlled oscillator.

FIG. 7 is a diagram showing a circuit configuration of a conventional oscillator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10, 20 Oscillator 11 Oscillation transistor 12 1/4 wavelength open end stub 13 Capacitor 21 High impedance line 30 Oscillator 31 Resonator 32 1/4 wavelength short end stub

Claims (3)

[Claims] 1. An oscillation transistor, a 波長 wavelength open end stub connected to a base or a gate of the oscillation transistor, and a resonance frequency lower than an oscillation frequency connected to a collector or a drain of the oscillation transistor. An oscillator comprising: a capacitor having: 2. The oscillator according to claim 1, wherein a high impedance line is connected to the capacitor in series. 3. The oscillator using the oscillator according to claim 1, wherein the oscillator and a resonator formed of a stub having a 波長 wavelength short-circuit end are magnetically coupled.