JP2018078534A - Oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stable high order harmonic wave oscillation circuit technique of high frequency band above milli-wave zone.SOLUTION: Target harmonic synchronization oscillation is realized when a resonator in harmonic resonance relation is coupled while sharing semiconductor oscillation devices (3, 6). More specifically, fundamental frequency (f0) oscillation is originated by a first resonator #1 of fundamental frequency (f0) band and the oscillation device, and a harmonic (mf0) is excited selectively and stably on a second resonator #2 coupling the device covalently. Since this oscillator is configured extremely simply, stable high order harmonic wave oscillation can be realized simply in high frequency band, compared with "a harmonic selection extract oscillation circuit" using harmonic orthogonality on a single resonator, that is an existing harmonic oscillation technology, or "a harmonic synchronization oscillation circuit" by electromagnetic coupling between harmonic resonance wave fields.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a technical field of a microwave / millimeter wave band or higher frequency band oscillator, and more particularly to a circuit configuration technology having a high-order harmonic synchronous oscillation function capable of super-high frequency band oscillation.

  There is a need for a stable, simple and higher frequency oscillation technique for high frequency band oscillation techniques such as millimeter wave, short millimeter wave band, and terahertz. For example, various wireless sensors and radar devices have been developed in various ways, and various needs are becoming apparent, not limited to wireless communication.

  FIG. 8 (a) is one of the basic conceptual diagrams of the harmonic oscillator configuration, and the harmonics are selectively extracted by actively utilizing the characteristics of the electromagnetic field distribution of the resonator wave field. Based on this basic concept, FIG. 5B is an oscillator that selectively extracts the fourth harmonic on the ring resonator by mounting a negative resistance circuit composed of a HEMT or the like on the ring resonator. Non-patent document 1). FIG. 6C is also based on this basic concept. By mounting a negative resistance circuit such as HEMT at an appropriate point of the half-wavelength line resonator, the second harmonic is suppressed. This is a Push-Push type oscillator that selectively excites and extracts fourth-order harmonics (Patent Document 1). These are based on the principle of exciting and selectively extracting harmonics of the target order using the orthogonality of the harmonic electromagnetic field distribution on a single resonator. For this reason, there is a limit to the selectivity of higher harmonic orders, and in particular, it is difficult to realize above the millimeter wave band. FIG. 8 (d) is another basic conceptual diagram for realizing a harmonic synchronous oscillator by electromagnetically coupling resonators having a harmonic (harmonic) resonance relationship. Since this is harmonic synchronization based on electromagnetic coupling, stable high-order synchronous oscillation is difficult.

  On the other hand, as a prior example of the planar circuit structure oscillator using the Gunn diode according to the embodiment of the present invention, for example, as shown in Non-Patent Document 2, a Gunn diode integrated chip is mounted on a quarter-wave resonator. There is a millimeter wave band oscillator that is surface-mounted (FIG. 8E). Patent Document 2 and Non-Patent Document 3 also report a circuit in which the ground via hole shown in FIG. 5E is replaced with a quarter-wavelength open end stub (FIG. 8F). Both are millimeter wave band planar circuit structure oscillators realized in the fundamental oscillation frequency band of Gunn diode.

JP 2007-194471 A Japanese Patent Laid-Open No. 2006-139983

Hai Xiao, et al. , “Basic Behavior of Quadruple-Push Oscillator Using Ring Resonator,” IEICE Trans. Electron. , Vol. E88-C, no. 7, pp. 1502-1508, July 2005. N. Nakagawa, et al. "77 GHz Planar Gunn VCOs on AlN Substrates Using Novell-Clip InP Gunn Diodes," 2000 IEEE MTT-S Digest, pp. 1205-1208, 2000.

(Problems of conventional technology)
Harmonic oscillation technology is effective for the generation of ultra-high frequency signals in the millimeter wave band and above, but there are many problems in realizing stable oscillation. For example, in harmonic synchronous oscillation by electromagnetic coupling of a resonant wave field as shown in FIG. 8D, it is generally difficult to realize stable high-order harmonic oscillation.

(Object of invention)
The present invention enables high-order harmonics to be generated in a high frequency band above the millimeter wave band by the combined effect of Gunn diodes, resonant tunneling diodes, and surface-mounted chips that integrate them and planar circuit technology suitable for miniaturization. An object of the present invention is to provide a circuit configuration technique that can be easily realized by the above.

  For this purpose, the present invention proposes an oscillation circuit that stably excites harmonic synchronous oscillation by a resonator having a harmonic (harmonic) resonance relationship sharing and coupling a semiconductor oscillation device. . As shown in FIG. 1, a stable fundamental frequency oscillation is generated by a first resonator (hereinafter referred to as resonator # 1) having a resonance frequency f0 in the fundamental oscillation frequency band and an oscillation device 3, and harmonic resonance is caused. Since the second resonator (hereinafter referred to as “resonator # 2”) having the relationship is coupled to the oscillation device 3 in common, the resonance frequency (hereinafter referred to as “mf0”) signal of the resonator # 2 is transmitted. Selectively resonant excitation. That is, the mf0 wave field, which is the mth harmonic that is harmonically synchronized with the f0 wave field of the resonator # 1, is stably excited on the resonator # 2.

  FIG. 2 shows four types of oscillators (hereinafter referred to as basic circuits) based on the basic conceptual diagram of the present invention in FIG. Here, the basic conceptual configuration of FIG. 1 is limited to a two-stage structure, and the resonator # 1 and the resonator # 2 are line resonances of integral multiples of a quarter wavelength at the respective resonance frequencies (f0, mf0). Use a vessel. As the semiconductor oscillation device 3, Gunn diode is assumed.

  In the circuit 1 in FIG. 2A, the resonator # 2 is connected to both ends of the resonator # 1, and the oscillation device 3 is connected in parallel to the connection portion. The m-th harmonic mf0 signal is extracted from the other end of the resonator # 2. FIG. 3 shows an embodiment in which this is realized by a microstrip line planar circuit.

  In the circuit 2 of FIG. 2B, the resonator # 1 is connected to both ends of the resonator # 2, and the oscillation device 3 is connected in parallel to the connection portion. The m-th harmonic mf0 signal or a 2mf0 signal that is a harmonic thereof is extracted from the midpoint of the resonator # 2. FIG. 4 shows an embodiment in which this is realized by a microstrip line planar circuit.

  In the circuit 3 of FIG. 2C, both the resonator # 1 and the resonator # 2 are coupled lines, and one end of each is connected, and the oscillation device 3 is connected in parallel to the connection portion. The m-th harmonic mf0 signal is extracted from the remaining other end of the resonator # 2. FIG. 5 shows an embodiment in which this is realized by a microstrip line planar circuit.

  In the circuit 4 of FIG. 2D, each of the resonator # 1 and the resonator # 2 is bent into a U-shape and both ends are connected to each other, and the oscillation device 3 is mounted on each connection portion. The mth harmonic mf0 signal or a 2mf0 signal that is a harmonic of the mth harmonic mf0 signal is output from the midpoint of the resonator # 2. An embodiment in which this is realized by a planar circuit of a microstrip line or a slot line is shown in FIG.

  In the four basic circuits shown in FIG. 2, the resonator # 1 having the fundamental oscillation frequency (f 0) band and the resonator # 2 having the resonance frequency mf 0 times its natural number (m) are covalently coupled to the oscillation device 3. Furthermore, it is a feature of the present invention that the circuit structure is very simple. As a result, it is more stable in the high frequency band than the harmonic selective extraction type oscillation circuit which is the conventional harmonic oscillation technique of FIG. 8A and the harmonic synchronization type oscillation circuit by electromagnetic coupling of FIG. 8D. High-order harmonic oscillation can be realized easily. As shown in FIGS. 8B and 8C, high-order harmonic selectivity is unnecessary as compared with the conventional harmonic oscillation technology that uses the orthogonality of the harmonic electromagnetic field distribution on a single resonator. It has excellent signal suppression and interference resistance, and is also suitable for mounting oscillation control functions such as frequency stabilization and noise reduction.

From the above features, the present invention has the following effects and possibilities.
(1) High-order harmonic oscillation with stable and good characteristics can be realized in the millimeter wave to short millimeter wave band and further to the sub-terahertz band.
(2) The semiconductor oscillation device and its integration, its chip mounting technology and planar circuit technology can be manufactured with high precision, and is suitable for realizing a high frequency band.
(3) Frequency variable control, stabilization of injection locking and phase locking, noise reduction processing, and frequency modulation can be easily implemented in the fundamental frequency (f0) band.
(4) The structure is suitable for mutual synchronization between adjacent oscillators, and two-dimensional development such as an oscillation array is possible.
(5) In addition to contributing to the new development of higher frequency bands, it is expected to develop various wireless application technologies such as various measurements and sensing from millimeter waves to terahertz.

This is a basic concept regarding the configuration of a high-order harmonic oscillator. Based on the basic concept, there are four basic circuits of a harmonic oscillator composed of two stages of line resonators (# 1, # 2) and the oscillation device 3. (Claims 1 and 2) 3 is a first embodiment based on the basic circuit of the circuit 1 of FIG. (Claims 1, 2, 3, 7) 3 is a second embodiment based on the basic circuit of the circuit 2 of FIG. Among them, (c) selectively extracts a 2mf0 signal that is a harmonic of the resonance frequency of the resonator # 2 by a slot line output circuit using magnetic field coupling. (Claims 1, 2, 4, 7, 9) 3 is a third embodiment based on the basic circuit of the circuit 3 of FIG. (Claims 1, 2, 5, and 7) 4 is a fourth embodiment based on the basic circuit of the circuit 4 of FIG. In (c), a 2mf0 signal that is a harmonic wave of the resonance frequency mf0 of the resonator # 2 is selectively extracted by a slot line output circuit using magnetic field coupling. (D) is an embodiment in which slot line resonators are used for the resonators # 1 and # 2. (Claims 1, 2, 6, 7, 9) It is a 5th example of the present invention. (A) sets the electrical length of the resonator # 1 to be the I wavelength, and (b) forms an antiphase wave field at the connection portion by electromagnetically coupling the half-wave resonator 10, and Push -Realize Push oscillation. (Claims 1, 2, 7, 8) It is explanatory drawing of a prior art. (A) is a basic conceptual diagram of a harmonic selection type oscillation circuit, (b) is a fourth harmonic oscillator using a ring resonator and a negative resistance circuit based on the basic concept, and (c) is the same. Based on the basic concept, it is a fourth harmonic oscillator composed of a half-wavelength line resonator and a negative resistance circuit. (D) is a basic conceptual diagram of a harmonic synchronous oscillator by electromagnetic coupling of a resonator. (E), (f) is an embodiment of a millimeter wave band fundamental frequency oscillator in which a Gunn diode integrated chip is surface-mounted.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. Each of the embodiments is an embodiment based on the four basic circuits shown in FIG. The resonator is mainly formed of a microstrip line or a slot line, and the oscillation device is a Gunn diode.

  FIG. 3 shows a first embodiment based on the basic circuit of the circuit 1 of FIG. In both cases, the # 1 resonator is bent into a U-shape, and the mf0 signal, which is the mth harmonic on the resonator # 2, is combined by electromagnetic coupling and the surface mount type Gunn diode integrated chip 6 is mounted. It is also a suitable circuit shape. In (a), the anode terminals of the two Gunn diode individual elements 3 are grounded via the via holes 4, and the cathode terminals are mounted in parallel at the connection between the resonator # 1 and the resonator # 2. Oscillation of the fundamental frequency f0 is generated by the resonator # 1 and via-hole grounding, and at the same time, the mth-order harmonic mf0 is selectively excited by the resonator # 2 sharing the oscillation device 3 and output to the port 5 by electromagnetic coupling. The basic principles of the circuits (b) and (c) are the same, but the former is a configuration in the case where the integrated chip 6 is surface-mounted, and the latter further uses the resonators # 1 and # 2 in order to eliminate via-hole grounding. The open end quarter-wave stubs 7 and 8 are formed at the respective resonance frequencies. (Claims 1, 2, 3, 7)

  FIG. 4 shows a second embodiment based on the basic circuit of the circuit 2 in FIG. In this embodiment, the resonator # 2 is U-shaped, and the mf0 signal, which is the mth harmonic on the resonator # 2, is extracted from the midpoint by electromagnetic coupling, and the Gunn diode integrated chip 6 is mounted. Therefore, the circuit shape is suitable. In (a), the anode terminals of the two Gunn diode individual elements 3 are grounded via the via holes 4, and the remaining cathode terminals are mounted in parallel on the connecting portions of the resonators # 1 and # 2. With this structure, oscillation of the fundamental frequency f0 occurs, and at the same time, the m-th harmonic mf0 is selectively excited by the resonator # 2. The basic principles of the circuits (b) and (c) are the same, and both have the configuration in which the integrated chip 6 is surface-mounted. In (c), the 2mf0 signal, which is a harmonic of the resonance frequency mf0 of the resonator # 2, is selectively extracted by magnetically coupling the midpoint of the resonator # 2 and the slot line 9 formed on the back surface of the substrate. In principle, the fundamental frequency signals f0 and mf0 can be completely suppressed by the magnetic field coupling output. (Claims 1, 2, 4, 7, 9)

  FIG. 5 shows a third embodiment based on the basic circuit of the circuit 3 of FIG. Resonator # 1 and resonator # 2 are both coupled lines to synthesize power from the mf0 signal, which is the m-th harmonic on resonator # 2, and to mount surface mounted Gunn diode integrated chip 6 The circuit configuration is suitable for. In (a), the anode terminals of the two Gunn diode individual elements 3 are grounded via the via holes 4, and the remaining cathode terminals are mounted in parallel on the connecting portions of the resonators # 1 and # 2. With this structure, oscillation of the fundamental frequency f0 occurs, and the mf0 signal of the mth harmonic is selectively excited by the resonator # 2 and output to the port 5. The basic principles of the circuits of (b) and (c) are the same, but the former used the integrated chip 6 to be surface-mounted and used the open-end quarter-wave stubs 7 and 8 to remove the via holes 4. The latter is a circuit in which the resonator # 1 and the resonator # 2 are simplified to a single line. The circuits of (b) and (c) can be expected to improve the order selectivity of the harmonic signal as compared with (a) of via-hole grounding. (Claims 1, 2, 5, and 7)

  FIG. 6 shows a fourth embodiment based on the basic circuit of the circuit 4 in FIG. Resonator # 1 and resonator # 2 are both U-shaped line resonators that output the mf0 signal, which is the m-th harmonic on resonator # 2, to port 5 by electromagnetic coupling and are surface mounted. The circuit shape is suitable for mounting a type integrated chip. In (a), the anode terminals of the two Gunn diode individual elements 3 are grounded via holes, and the remaining cathode terminals are mounted in parallel at the connecting portions of the resonators # 1 and # 2. With this structure, oscillation of the fundamental frequency f0 occurs, and at the same time, the mf0 signal that is the mth harmonic is selectively excited and output to the port 5. The basic principles of the circuits (b) to (d) are the same. (B) and (c) are via hole grounding arrangements suitable for surface mounting the integrated chip 6. In (c), a 2mf0 signal, which is a double wave, can be output by magnetic field coupling between the slot line 9 on the back surface of the substrate and the resonator 2. (D) is a circuit in which the oscillation device 3 is mounted in parallel at the connection portion of the resonators # 1 and # 2 formed by slot lines. (Claims 1, 2, 6, 7, 9)

  FIG. 7 shows a fifth embodiment of the push-push oscillation type. A circuit of the first embodiment based on the basic circuit of the circuit 1 (FIGS. 3A and 3C) is modified to generate a fundamental frequency band wave having an opposite phase at the connection point between the resonator # 1 and the resonator # 2. A field is formed on resonator # 1. In FIG. 7A, the electrical length of the resonator # 1 is set to one wavelength, and in FIG. 7B, the resonator # 1 and the half-wave resonator 10 are electromagnetically coupled to each other, thereby causing an anti-phase wave. Create a field. As a result, in principle, the output of fundamental frequency components and odd-order harmonic components can be completely suppressed. In the case of this Push-Push operation, in principle, the harmonic order m needs to be an even number. (Claims 1, 2, 7, 8)

  In the above, five embodiments of the two-stage Gunn diode harmonic oscillators of the resonators # 1 and # 2 have been described. However, it is easy to expand to a higher-order oscillator using three or more stages and other high-frequency devices. is there. In addition, it has a simple circuit structure suitable for low-noise control such as frequency variable control and phase synchronization and implementation of stabilization functions, and multi-element array oscillation is also possible by mutual synchronization between oscillators.

  As a simple signal generation technology in the high frequency band from millimeter waves to short millimeter waves and from sub-terahertz to terahertz, it is expected to stimulate various needs and new applications such as measurement and sensing. In particular, an oscillation system with a planar circuit structure using Gunn diodes, resonant tunneling diodes, etc. as an oscillation device can be realized easily and at low cost, and by integrating RF functions such as a planar antenna, transmission / reception of various needs can be achieved. Technology development for the development of receiver modules can also be expected.

# 1 Resonator with fundamental oscillation frequency f0 (Resonator # 1)
# 2 Resonator with mth harmonic frequency mf0 (resonator # 2), m: natural number 3 oscillation device, oscillation element such as Gunn diode or resonant tunnel diode 4 ground via hole 5 microstrip line oscillation output port 6 oscillation device Integrated chip, surface-mount type integrated chip 7 1/4 wavelength tip open stub 8 at fundamental oscillation frequency f0 Quarter wave tip open stub 9 at mth harmonic frequency mf0 Slot line oscillation output port 10 Push-Push operation A half-wave resonator for λ 1 wavelength λ (): means one wavelength at a frequency in ().

Claims (9)

  A first resonator having a resonance frequency in the fundamental oscillation frequency band and a second resonator having a harmonic resonance relationship whose resonance frequency is an integral multiple of the fundamental oscillation frequency share a semiconductor oscillation device. An oscillator characterized by being coupled.   The first resonator and the second resonator are line resonators whose length is an integral multiple of a quarter wavelength at each resonance frequency, and the semiconductor oscillation device is a two-terminal negative resistance element or An oscillator comprising the integrated chip, wherein the semiconductor oscillation device is mounted on a connection portion of the resonator, and an oscillation signal is output from the second resonator by electromagnetic coupling.   In Claim 1, 2, the first resonator is bent in a U-shape, the second resonator is connected to both ends thereof, and the semiconductor oscillation device is mounted at the connection portion, the oscillation output is the An oscillator characterized by being extracted by electromagnetic coupling from the remaining other end of the second resonator.   In Claims 1 and 2, the second resonator is bent into a U shape, and the first resonator is connected to both ends of the second resonator, and the semiconductor oscillation device is mounted at the connection portion, and the oscillation output is the An oscillator characterized by being extracted by electromagnetic coupling from a second resonator.   In Claim 1, 2, The first resonator and the second resonator are coupled line resonators, each one end is connected, the semiconductor oscillation device is mounted on the connection portion, the oscillation output is the An oscillator characterized by being extracted by electromagnetic coupling from the remaining other end of the second resonator.   In Claim 1, 2, the first resonator and the second resonator are bent in a U-shape, both ends thereof are connected to each other, the semiconductor oscillation device is mounted at the connection portion, the oscillation output is the An oscillator characterized by being extracted from the second resonator by electromagnetic coupling.   7. The semiconductor oscillation device according to claim 3, wherein the semiconductor oscillation device is a Gunn diode, a resonant tunneling diode (RTD), or an integrated chip thereof, and is mounted using via-hole grounding in the connection portion or instead of the via-hole. And an oscillator characterized by being mounted with high-frequency grounding with a quarter-wavelength open-end stub in the resonance frequency bands of the first resonator and the second resonator, respectively.   8. The oscillator according to claim 3, wherein a resonance wave field in which the fundamental frequency signals in the connection portions are in opposite phases is formed on the first resonator.   7. The oscillator according to claim 4, wherein a frequency signal that is an even multiple of a resonance frequency of the second resonator is extracted by magnetic field coupling with a midpoint of the second resonator.

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