JPH05102727A - Oscillator - Google Patents

Abstract

PURPOSE:To make the length of a line of a resonator considerably short and to extract two outputs of a fundamental wave and a 2nd harmonic by providing a gap to the resonator employing a ring transmission line and connecting a capacitor to the gap. CONSTITUTION:A gap is provided in a ring transmission line 9 of a resonator 6 and a lumped constant capacitor 10 is connected to the gap. The oscillator is provided with the circuit 6 comprising a resonance capacitor and the transmission line connected in parallel with the capacitor of the same configuration symmetrically. Since a phase difference of 180 deg. exists in two outputs of the oscillator section 4, the outputs are synthesized in opposite phase by an opposite phase synthesis circuit 7 to extract a fundamental wave component of the oscillator with a double amplitude. Moreover, an in-phase component synthesis circuit 8 implements in-phase synthesis to extract a 2nd harmonic component doubly. As a result, the resonator is made small and the oscillator from which two outputs of a fundamental wave and a 2nd harmonic are extracted is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to oscillators for various radio equipment for high frequencies, communication equipment, measuring instruments and the like.

[0002]

2. Description of the Related Art TEM mode resonators are most often used for small resonators used in high frequency oscillators, and publications (for example, Yoshihiro Konishi "Microwave Integrated Circuit", Industrial Report) are available for these resonators. ) Has been described a lot. FIG. 3 (a) shows an example of a half-wave resonator with an open tip.
Reference numeral 1 is a resonance line. FIG. 2B shows a resonator having a hairpin structure in which FIG.

A push-push oscillator is often used as a structure of a high-frequency oscillator using the above-mentioned resonator (for example, a microwave journal (Push-Push VCO Design with CAD Tools, Zvi Nativ of February 1989).
and Yair Shur, Mic-rowave Journal February 198
9)).

The conventional oscillator will be described below. FIG. 6 shows the overall circuit configuration of a conventional oscillator. In FIG. 6, 3 is a resonator section, 4 is an oscillator section having two identical and symmetrical oscillation circuits such as Colpitts oscillation circuits, and 5 is a synthetic circuit having a transmission line having the same electric length.

Regarding the oscillator configured as described above,
The operation will be described below. First, the two outputs from the oscillator unit 4 are 180 ° out of phase with each other, the fundamental wave and the odd harmonic components are canceled by the synthesizing circuit 5, and only the even harmonic components are doubled and output. You can

[0006]

However, in the above-mentioned conventional configuration, the resonator line length is as long as 1/2 wavelength, and the area occupied by the resonator is large in order to obtain the desired resonant line length. There was a problem that the shape could not be reduced. Further, when a frequency synthesizer is configured by using the above-mentioned oscillator in a phase locked loop circuit, a frequency divider that directly divides the output frequency is required, but a high-speed frequency divider consumes more power at an accelerating rate as the frequency increases. Had the problem of becoming.

The present invention solves the above-mentioned problems of the prior art, and provides a frequency synthesizer with low power consumption by providing an oscillator capable of taking out two outputs of a fundamental wave and a second harmonic while reducing the shape of the resonator. Etc. are intended to be realized.

[0008]

In order to achieve this object, the present invention provides a resonance circuit constituted by a resonance capacitor and a transmission line connected in parallel with the resonance circuit, which is the same and symmetrical to each other.
It has a configuration including an oscillator section composed of two oscillation sections, a combining circuit for combining opposite phases of two outputs of the oscillator section, and a combining circuit for combining in-phase of two outputs of the oscillator section. ..

[0009]

According to the present invention, by providing a gap in a resonator using a ring-shaped transmission line and connecting a capacitance to that portion, the resonator line length can be made significantly smaller than that of a 1/2 wavelength resonator, and A high frequency synthesizer can be realized with low power consumption by extracting the second harmonic wave from the external output and using the fundamental wave output in the phase synchronization circuit.

[0010]

(Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a circuit diagram of an oscillator according to an embodiment of the present invention. In FIG. 1A, 4 is an oscillating unit, 6 is a resonator, 7 is an anti-phase synthesizing circuit, and 8 is an in-phase synthesizing circuit. The resonator 6 is shown in FIGS.
(A), (b), the anti-phase synthesis circuit 7 has the circuit configuration of FIG. 2 (c), and the in-phase synthesis circuit 8 has the circuit configuration of FIG. 2 (d).

Regarding the oscillator configured as described above,
The operation will be described. First, by providing a gap in the ring-shaped transmission line and connecting the capacitance to that portion, the resonator line length can be significantly shortened below 1/2 wavelength.

FIG. 1B shows a structure of the resonator 6, in which a ring-shaped transmission line 9 is provided with a gap and a lumped constant capacitance 10 is connected to the gap.

FIG. 1C shows a structure of the resonator 6 in which a gap is provided in the ring-shaped dielectric 11 and the lumped constant capacitance 12 is connected to the gap.

FIG. 2A shows a structure of the resonator 6 which uses a ring-shaped transmission line 13 having a parallel coupling line portion. Here, the impedance of the single line portion is Z _s , and the even mode impedance of the parallel coupled line portion is Z _s .
_{If pe} and odd mode impedance are Z _po , Z _s ² = Z
_pe / Z _po .

FIG. 2 (b) shows a configuration of the resonator 6 using a parallel coupling line portion and a ring-shaped transmission line 14 whose impedance is changed stepwise with respect to the parallel coupling line portion. Here, if the impedance of the single line portion is Z _s , the even mode impedance of the parallel coupled line portion is Z _pe , and the odd mode impedance is Z _po , then Z _s ²
By setting> Z _pe · Z _po , the resonator length can be further shortened as compared with that of FIG.

With the above structure, it is possible to realize a compact resonator in which the phases at both ends of the resonator 6 are different by 180 ° at the resonance frequency.

Since the oscillating unit 4 has the same construction as the conventional one, its explanation is omitted here. Since the two outputs from the oscillating unit 4 have a phase difference of 180 ° with each other, the fundamental wave component of the oscillator can be doubled and taken out by synthesizing the two outputs in reverse phase. Further, if the in-phase synthesis is performed, the second harmonic component can be doubled and taken out.

FIG. 2C shows the configuration of the anti-phase synthesizing circuit 7 of the oscillator, in which the second transmission line 15 having the same electrical length on both sides and being parallel to the virtual ground point of the ring-shaped resonator is arranged. The one end of the second transmission line 15 is grounded and the other end is an output.

FIG. 2D shows a configuration of the in-phase synthesis circuit 8 of the oscillator, which uses the transmission line 16 having the same electrical length.

The two outputs from the oscillating unit 4 are respectively taken out by capacitive coupling. By setting the coupling area to a small value, the isolation between the oscillating circuits is secured even when the two oscillating circuits are directly connected. can do.

FIG. 2 (d) shows the configuration of the in-phase synthesizing circuit 8 of the oscillator, in which both outputs of the two oscillating circuits constituting the oscillator section 4 are built in the oscillator section 4 and the capacitors 16a, 1 having a small value are provided.
It is directly connected via 6b.

With the above configuration, when a frequency synthesizer is constructed by using the above-mentioned oscillator in a phase locked loop, a high frequency output can be obtained by using the in-phase synthesis circuit output as an external output, and the anti-phase synthesis circuit output can be obtained. A frequency synthesizer with low power consumption can be realized by inputting the frequency divider connected to the oscillator.

As described above, according to the present embodiment, the resonance circuit constituted by the resonance capacitor and the transmission line connected in parallel to the capacitance and the oscillator section constituted by the two symmetrical and identical oscillating sections In an oscillator including a synthesizing circuit for synthesizing opposite phases of two outputs of the oscillator section and a synthesizing circuit for synthesizing in-phase of two outputs of the oscillator section, the anti-phase synthesizing circuit is connected to the resonator side, By connecting the in-phase synthesizer circuit to the output of the oscillator section, the resonator line length can be made much smaller than that of the half-wave resonator, and when the oscillator is used as a phase-locked loop circuit to construct a frequency synthesizer, a high frequency external output is used. And the power consumption can be reduced.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 (a) shows an overall circuit diagram of an oscillator in one embodiment of the present invention. In FIG. 3A, 4 is an oscillating unit, 6 is a resonator, 17 is an anti-phase synthesizing circuit, and 18 is an in-phase synthesizing circuit. Since the oscillating unit 4 and the resonator 6 are the same as those in FIG. Is omitted. The anti-phase synthesis circuit 17 has the circuit configuration shown in FIGS. 3B, 3C, 4A, and 4B, and the in-phase synthesis circuit 18 has the circuit configuration shown in FIG. 4C.

In FIG. 3B, an input / output balanced-unbalanced conversion circuit 19 is used as the configuration of the anti-phase synthesis circuit 17 of the oscillator.

In FIG. 3C, a rat race circuit 20 is used as the configuration of the anti-phase synthesis circuit 17 of the oscillator.

FIG. 4A shows a configuration of the anti-phase synthesizing circuit 17 of the oscillator, which uses the transmission line 21 whose electrical length differs by 180 ° at the oscillation frequency.

FIG. 4B shows a configuration of the anti-phase synthesizing circuit 17 of the oscillator, which includes a differential amplifier pair 22 and 23, a constant current source 24, and resistors 25 and 26.
Is used.

FIG. 4C shows a configuration of the in-phase combining circuit 18 of the oscillator, which uses the transmission line 28 having the same electrical length.

With the above configuration, when a frequency synthesizer is constructed by using the above-mentioned oscillator in a phase locked loop, a high frequency output can be obtained by using the output of the in-phase synthesis circuit as an external output, and the output of the anti-phase synthesis circuit can be obtained. A frequency synthesizer with low power consumption can be realized by inputting the frequency divider connected to the oscillator.

As described above, according to the present embodiment, the resonance circuit constituted by the resonance capacitor and the transmission line connected in parallel with the capacitance and the oscillator unit constituted by the two symmetrical and identical oscillating units. And an synthesizing circuit for synthesizing a reverse phase of the two outputs of the oscillator section and a synthesizing circuit for synthesizing the same phase of the two outputs of the oscillator section, the anti-phase synthesizing circuit is connected to the output of the oscillator section, By connecting the in-phase combiner circuit to the resonator side, the resonator line length can be made much smaller than that of the half-wave resonator, and when the above-mentioned oscillator is used as a phase-locked circuit to construct a frequency synthesizer, a high-frequency external output And the power consumption can be reduced.

[0034]

As described above, according to the present invention, a resonance circuit composed of a resonance capacitor and a transmission line connected in parallel to the capacitance, and an oscillator section composed of two identical and symmetric oscillators are provided. By providing a synthesizing circuit for synthesizing the opposite phases of the two outputs of the oscillator section and a synthesizing circuit for synthesizing the in-phase of the two outputs of the oscillator section, the resonator line length is reduced to 1/2.
In addition to being able to be made much smaller than a wavelength resonator, a high frequency external output can be obtained and power consumption can be reduced when a frequency synthesizer is constructed by using the above oscillator in a phase locked loop.

[Brief description of drawings]

FIG. 1 is an overall block wiring and individual element diagram of an oscillator according to a first embodiment of the present invention.

FIG. 2 is an individual element diagram of the oscillator according to the first embodiment of the present invention.

FIG. 3 is an overall block connection and individual element diagram of an oscillator according to a second embodiment of the present invention.

FIG. 4 is an individual element diagram of an oscillator according to a second embodiment of the present invention.

FIG. 5 is a plan view of a conventional resonator.

FIG. 6 is a block connection diagram of a conventional oscillator.

[Explanation of symbols]

 1 Resonator 2 Resonator 3 Resonator 4 Oscillator 5 Combined Circuit 6 Resonator 7 Reverse Phase Combined Circuit 8 In-Phase Combined Circuit 9 Resonator 10 Capacitance 11 Resonator 12 Capacitance 13 Resonator 14 Resonator 15 Transmission Line 16 In-Phase Combined Circuit 17 Anti-Phase Combining Circuit 18 In-Phase Combining Circuit 19 Anti-Phase Combining Circuit 20 Anti-Phase Combining Circuit 21 Anti-Phase Combining Circuit 22 Transistor 23 Transistor 24 Constant Current Source 25 Resistor 26 Resistor 27 Anti-Phase Combining Circuit 28 In-Phase Combining Circuit

Claims (15)

[Claims] 1. A resonance circuit composed of a resonance capacitor and a transmission line connected in parallel to the resonance capacitor, an oscillator section composed of two identical and symmetrical oscillation sections, and two of the oscillator section. An oscillator, comprising: a synthesizing circuit for synthesizing opposite phases of two outputs and a synthesizing circuit for synthesizing in-phase of two outputs of the oscillator section. 2. The oscillator according to claim 1, wherein a ring-shaped transmission line is provided with a gap as a resonance circuit, and a lumped constant capacitance is connected to the gap. 3. The oscillator according to claim 1, wherein a ring-shaped dielectric is provided with a gap as a resonance circuit, and a lumped constant capacitance is connected to the gap. 4. A ring-shaped transmission line having a parallel coupling line portion is used as the resonance circuit.
The described oscillator. 5. The oscillator according to claim 1, wherein a parallel coupling line portion and a ring-shaped transmission line whose impedance is changed stepwise with respect to the parallel coupling line portion are used as the resonance circuit. 6. The oscillator according to claim 1, wherein the anti-phase synthesis circuit is connected to the resonator side, and the in-phase synthesis circuit is connected to the output of the oscillator section. 7. An anti-phase combining circuit, wherein a second transmission line having electrical lengths on both sides that are equal and parallel to a virtual ground point of the ring-shaped resonator is arranged, and one end of the second transmission line is provided. 7. The oscillator according to claim 6, wherein the oscillator is grounded and the other end is an output. 8. The oscillator according to claim 6, wherein transmission lines having the same electrical length are used as the in-phase combining circuit. 9. The oscillator according to claim 6, wherein two oscillating units are directly connected to each other as the in-phase synthesizing circuit. 10. The oscillator according to claim 1, wherein the anti-phase synthesis circuit is connected to the output of the oscillator section, and the in-phase synthesis circuit is connected to the resonator side. 11. The oscillator according to claim 10, wherein an input / output balanced-unbalanced conversion circuit is used as the anti-phase synthesis circuit. 12. The oscillator according to claim 10, wherein a rat race circuit is used as the anti-phase synthesis circuit. 13. The oscillator according to claim 10, wherein transmission lines having different electrical lengths of 180 ° at an oscillation frequency are used as the anti-phase synthesis circuit. 14. The oscillator according to claim 10, wherein a differential amplifier is used as the anti-phase synthesis circuit. 15. A transmission line having equal electrical lengths and using transmission lines having the same electrical lengths as a common-mode synthesis circuit, while outputs are taken out from two points on said resonators that are symmetrical and symmetrical in electrical length to a virtual ground point of the ring-shaped resonator. 11. The oscillator according to claim 10, wherein: