JP3642872B2 - Resonator for YIG device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resonator used in a YIG (yttrium iron garnet) device or the like constituting an oscillator or a filter in a microwave frequency band.
[0002]
[Prior art]
The YIG device is a device for a tunable resonator / oscillator in the microwave band that utilizes the characteristic that the Q of the three-metal ferrimagnetic resonance of yttrium, iron, and garnet is very high.
[0003]
7 is a cross-sectional view of a conventional YIG device, FIG. 8 (1) is a plan view of the resonator portion, FIG. 8 (2) is a side view of the resonator portion, and FIG. 9 is 3.8-4 of this resonator. It is a figure which shows the reflective characteristic in 0.2 GHz.
[0004]
As shown in FIG. 7, in the YIG device, the open surface of the upper part of the crucible magnetic core 1 having the central axis 2 is covered with a plate-like magnetic core 3, and the tip surface of the central axis 2 and the plate-like magnetic core 3 are covered. YIG element 4 is arranged between the two. The YIG element 4 is attached to one end of a support bar 5 parallel to the inner surface of the plate-like magnetic core 3. The other end of the support bar 5 is fixed to the inner surface of the plate-like magnetic core 3 with a fixture 6.
[0005]
A hybrid integrated circuit board 7 is also fixed to the inner surface of the plate-like magnetic core 3. A coupling coil 8 having a semicircular shape (0.9 mmφ) is attached on the hybrid integrated circuit substrate 7 so that the YIG element 4 (0.5 mmφ) is positioned at the center (FIG. 8).
[0006]
When configuring the oscillator, although not shown, an oscillation circuit using the YIG element 4 as a resonator is formed, and an amplifier of the oscillation output is formed on the hybrid integrated circuit board 7 and used.
[0007]
A coil 9 is formed around the central axis 2 so that a DC voltage can be applied to the coil 9 from the power supply terminal 10 and a current can be applied to the coil 9 to apply a magnetic field to the YIG element 4. By applying this magnetic field, the YIG element 4 resonates and can act as an oscillator. Then, the oscillation output is output to the outside from the coaxial connector 11 attached to the plate-like magnetic core 3. Since the resonance frequency of the YIG element 4 is proportional to the strength of the magnetic field, a desired resonance frequency can be obtained by controlling the current flowing through the coil 9.
[0008]
YIG devices are mainly used in local oscillators and filters of spectrum analyzers and network analyzers, and are important components that affect the performance of these measuring instruments. Therefore, in order to improve their performance, the characteristics of YIG devices have been improved.
[0009]
[Problems to be solved by the invention]
The resonance characteristics of the YIG device are determined by the YIG element 4 and the coupling coil 8 constituting the resonator. That is, if the crystal lattice of the YIG element 4 is defective, is not a perfect sphere, or the high-frequency magnetic field produced by the coupling coil 8 is not uniform, the precession of the spin inside the YIG element 4 is uniform. It appears as deterioration of RF characteristics such as Q deterioration, spurious generation, parasitic resonance generation (FIG. 9), and the like. In order to prevent this, it can be considered that the crystal growth of the YIG element 4 and the processing into a sphere are made more complete. However, it is very difficult to manufacture the YIG element 4 having a higher quality than that at present. Therefore, it is desired to prevent the deterioration of the RF characteristics by devising the coupling coil 8 side.
[0010]
Further, in recent measurement applications such as digital communication, there is a demand for analyzing a short-time spectrum such as a burst signal, and the need to sweep the YIG device at a higher frequency has been increased. Conventionally, the gap between the crucible magnetic core 1 and the plate-like magnetic core 3 has been made narrower. By reducing the number of windings of the coil 9 for generating the same magnetic field and reducing the inductance, a high-speed frequency sweep is enabled. Normally, a resonator (YIG element 4, coupling coil 8), hybrid integrated circuit board 7 and the like must be mounted in this space, so the resonator itself must be miniaturized in order to narrow the interval. However, it is very difficult to reduce the size of a resonator that is currently used in order to maintain the characteristics.
[0011]
An object of the present invention is to provide a resonator for a YIG device in which the uniformity of a high-frequency magnetic field generated by a coupling coil is good and parasitic resonance is suppressed.
[0012]
Another object of the present invention is to provide a small resonator for a YIG device while maintaining the same performance as a conventional coupling coil.
[0013]
[Means for Solving the Problems]
In the resonator according to the present invention , the coupling coil is mounted on the hybrid integrated circuit board fixed to the inner surface of the plate-like magnetic core so that the YIG element faces the tip surface of the central axis of the crucible magnetic core. In the resonator for a YIG device, the coupling coil includes two coupling coils having the same shape and arranged coaxially apart from each other by a certain distance.
[0014]
The present invention is a coupling coil of the resonator portion of the YIG devices, from conventional mere loop, in which to arrange side by side two loops coaxially. By doing so, the uniformity of the high-frequency magnetic field generated by the coupling coil is improved, and the parasitic resonance of the resonator is suppressed, thereby preventing the deterioration of the RF characteristics of the YIG device.
[0015]
Since this change only changes the configuration of the coupling coil portion, the conventional parts can be used as they are, and can be easily used in current YIG devices. Accordingly, it is possible to easily improve the performance of a conventional spectrum analyzer or the like.
[0016]
In the resonator according to the present invention, a notch is formed in the hybrid integrated circuit board, and a part of the two coupling coils protrudes into the notch.
[0017]
Therefore, it is possible to reduce the size of the resonator itself while maintaining the same performance as the conventional coupling coil. As a result, the interval between the magnetic cores can be made narrower, and a small YIG device capable of frequency sweeping can be made. By mounting this YIG device on a spectrum analyzer or the like, spectrum analysis can be performed by sweeping the frequency at a higher speed, so that it can be applied to recent applications such as digital wireless communication devices. Moreover, the downsizing of the YIG device has the advantage that the size of the measuring instrument can be reduced and the power consumption can be reduced at the same time.
[0018]
【Example】
Next, embodiments of the present invention will be described with reference to the drawings.
[0019]
1A and 1B are a plan view and a side view of a resonator portion of a resonator for a YIG device according to a first embodiment of the present invention.
[0020]
In this embodiment, the coupling coils 12a and 12b are formed by processing a 50 μm diameter gold wire into a semicircle with a diameter of 0.9 mm in a half turn, so that the uniformity of the high frequency magnetic field is the best. L = 0.45 mm apart and arranged side by side on the same axis. The YIG element 4 is located at an intermediate point on the axis of the coupling coils 12a and 12b, and is the same as the conventional one (0.5 mmφ).
[0021]
FIG. 2 is a diagram showing a magnetic field distribution generated on the central axis of the coupling coils 12a and 12b having a radius of 1 mm. The vertical axis is the relative strength of the magnetic field when the magnetic field strength when L = 0 is 1, the horizontal axis is the coordinate on the central axis of the coupling coils 12a and 12b, and 0 is between the coupling coils 12a and 12b. Corresponds to the center point. In FIG. 2, the magnetic field is obtained when the positions 1 of the coupling coils 12a and 12b are 0, ± 0.2 mm, ± 0.4 mm, ± 0.6 mm, ± 0.8 mm, ± 1.0 mm, and ± 0.5 mm, respectively. Distribution is shown.
[0022]
When the coupling coils 12a and 12b are arranged at points of +0.5 mm and −0.5 mm from the center point, the uniformity of the magnetic field is the best. When the coupling coils 12a and 12b are brought closer from the position of ± 0.5 mm, the magnetic field distribution becomes mountainous, and when the interval is zero, the uniformity of the magnetic field becomes the worst. When the coupling coils 12a and 12b are moved away from the position of ± 0.5 mm, the magnetic field distribution forms a valley at the center.
[0023]
In the above, an example in which the dimensions are specifically increased is shown, but the uniformity is not limited to this example. When the radius of the coupling coils 12a and 12b is D, it is known that the uniformity of the magnetic field is best when the two coupling coils 12a and 12b are arranged at a distance D apart.
[0024]
According to the present embodiment, the high frequency magnetic field can be made more uniform than the conventional one, and as a result, parasitic resonance can be suppressed as shown in FIG.
[0025]
FIG. 3 is a diagram showing the reflection characteristics at 3.8 to 4.2 GHz of the resonator for the YIG device of this example.
[0026]
The distortion seen in the reflection characteristic (FIG. 9) of the resonator for conventional YIG devices is hardly seen. In the case of an oscillator, since the distortion of the reflection characteristic appears as a parasitic oscillation or the like, it can be seen that the parasitic resonance is suppressed by the absence of the distortion.
[0027]
4A and 4B are a plan view and a side view of the resonator portion of the resonator for a YIG device according to the second embodiment of the present invention.
[0028]
In the present embodiment, the two coupling coils 13a and 13b obtained by processing a gold wire having a diameter of 50 μm into a circular shape having a diameter of 0.7 mm and wound in 1.5 turns have L = They are arranged coaxially opposite each other by 0.35 mm. The YIG element 4 is located at an intermediate point on the two axes. The YIG element 4 is the same as the conventional one (0.5 mm). Thus, the diameter of the resonator can be reduced from the conventional 0.9 mm of FIG. 8 to 0.7 mm while using the YIG element 4 having the same diameter as that of the conventional resonator. In the case of this embodiment, as shown in FIG. 4B, the hybrid integrated circuit board 7 is cut to form a notch, and the lower side of the coil is projected into the notch of the hybrid integrated circuit board 7. Therefore, the height can be further suppressed, and the substantial height of the resonator is about half that of the conventional one. As described above, since the height of the resonator could be suppressed, the distance between the magnetic cores 1 and 3 could be narrowed, and the frequency sweep speed could be tripled compared to the conventional one. Also, the volume of the coil 9 could be reduced to 1/5 of the conventional volume.
[0029]
FIG. 5 shows the magnetic field distribution when the radius of the coupling coils 13a and 13b is 0.8 mm and the coupling coils 13a and 13b are arranged at the point l = ± 0.4 mm where the uniformity of the magnetic field is the best. The other lines are the data of FIG. 5 (coupled coil with a radius of 1 mm). As a result of the miniaturization, the range in which the magnetic field is uniform is narrowed, but it is still understood that the magnetic field has a sufficient degree of magnetic field uniformity compared to the conventional one.
[0030]
Therefore, even if it is smaller than the diameter of the loop of the conventional coupling coil, the uniformity of the high frequency magnetic field is improved, so that the same performance as the conventional one can be exhibited.
[0031]
FIG. 6 is a diagram showing the reflection characteristics of this resonator from 3.8 to 4.2 GHz. It can be seen that the characteristics of the conventional resonator (FIG. 9) are almost equal. When actually oscillating, the conventional resonator oscillated in the band of 3.5 GHz to 8.3 GHz, but this resonator oscillated at 3.5 to 8.9 GHz. I couldn't.
[0032]
In the above embodiments, the shape of the coupling coil is semicircular or circular, but is not limited thereto. The resonator of the present invention can also be used for devices other than YIG devices.
[0033]
【The invention's effect】
As described above, the present invention has the following effects.
(1) According to the first aspect of the present invention, by using two coupling coils side by side, the high frequency magnetic field applied to the YIG element can be made uniform, thereby reducing the parasitic resonance.
(2) according to claim 2 invention, by projecting a part of the two coupling coils facing in the notches of the substrate, to reduce the gap of the magnetic circuit (period of the magnetic core) than the prior art And the resonator can be miniaturized.
[Brief description of the drawings]
FIG. 1 is a plan view and a side view of a resonator portion of a resonator for a YIG device according to a first embodiment of the present invention.
FIG. 2 is a graph showing a magnetic field distribution generated on the central axis of the coupling coils 12a and 12b in the first embodiment.
FIG. 3 is a diagram showing reflection characteristics at 3.8 to 4.2 GHz of the YIG device resonator according to the first embodiment;
FIGS. 4A and 4B are a plan view and a side view of a resonance portion of a resonator for a YIG device according to a second embodiment of the present invention. FIGS.
FIG. 5 is a diagram showing a magnetic field distribution generated on the central axis of the coupling coils 13a and 13b in the second embodiment.
FIG. 6 is a diagram showing reflection characteristics at 3.8 to 4.2 GHz of a resonator for a YIG device according to a second embodiment.
FIG. 7 is a cross-sectional view of a conventional resonator for a YIG device.
FIGS. 8A and 8B are a front view and a side view of a resonator portion of the resonator for the YIG device of FIG.
9 is a diagram showing reflection characteristics at 3.8 to 4.2 GHz of the resonator for the YIG device shown in FIG. 7;
[Explanation of symbols]
1 vase-shaped magnetic core 2 central axis 3 plate-like magnetic core 4 YIG element 5 support bar 6 fixture 7 hybrid integrated circuit board 8 coupling coil 9 coil 10 power supply terminal 11 coaxial connectors 12a and 12b coupling coils 13a and 13b coupling coil

Claims (2)

In the resonator for a YIG device, the coupling coil is mounted on the hybrid integrated circuit board fixed to the inner surface of the plate-like magnetic core so that the YIG element faces the tip surface of the central axis of the crucible magnetic core . A resonator for a YIG device , characterized in that the coupling coil is composed of two coupling coils having the same shape and arranged coaxially apart from each other by a certain distance. The hybrid integrated circuit is cutout portion is formed on the substrate, the portion of the two coupling coils are projecting the notch portion, YIG device for resonator according to claim 1.

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