JPH0818309A - Exciter for yig device - Google Patents

Abstract

PURPOSE:To increase the magnetic response speed by constituting radiation fins in parallel with the center axis of a bowlshaped magnetic core. CONSTITUTION:Grooves are constituted approximately in parallel with a center axis 12 of a bowl-shaped magnetic core 11 to form radiation fins 24, and a YIG element 14 is arranged between the shaft 12 and a plate-shaped magnetic core 13, and this magnetic core 11 is formed on a substrate (hybrid integrated circuit) 17. Since this exciter for YIG device has the same coil and exciting current as conventional though the device is miniaturized, the power consumption is not changed, and consequently, the calorific value is not changed, and the heat generated by the YIG device is sufficiently radiated by radiation fins which minimize the magnetic resistance. Since the magnetic resistance is minimized, the magnetic response speed is increased, and the device quickly responds regardless of the stepped exciting current. Consequently, the small-sized YIG device is realized which is built in a small-sized apparatus and has a high magnetic response speed, and the technical effect is large.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exciter used in a YIG (ytterbium iron garnet single crystal) device which constitutes an oscillator or a filter in a microwave frequency band, and more particularly to a heat-dissipating vase-type magnetic core. Regarding

[0002]

2. Description of the Related Art FIG. 2 is a sectional view showing an outline of a YIG device. In the YIG device, the open surface of the pot-shaped magnetic core 11 having the central axis 12 is covered with the plate-shaped magnetic core 13,
Between the tip surface of the central shaft 12 and the plate-shaped magnetic core 13, Y
The IG element 14 is arranged. The YIG element 14 is attached to one end of a support rod 15 parallel to the inner surface of the plate-shaped magnetic core 13, and the other end of the support rod 15 is fixed to the inner surface of the plate-shaped magnetic core 13 with a fixture 16. A substrate (hybrid integrated circuit) 17 is fixed to the inner surface of the plate-shaped magnetic core 13.

A semicircular coupling ring 18 is attached to the substrate 17 so that the YIG element 14 is located at the center thereof, and the coupling ring 18 is formed on the substrate 17. In the case of an oscillator, although not shown, an amplifier connected to an oscillating circuit having the resonating YIG element 14 as a resonator and amplifying its oscillation output is also formed on the substrate 17. A coil 19 is wound around the central axis 12, a DC voltage is applied from a power supply terminal 20, an exciting current I is caused to flow through the coil 19, and the central axis 12 of the pot-shaped magnetic core 11 and an outer pot-shaped magnetic core. Magnetic flux Φ in the magnetic circuit composed of 11 and the plate-shaped magnetic core 13.
Is generated and the magnetic field H can be applied to the YIG element 14. By applying this magnetic field H, YIG
The element 14 resonates and oscillates and can act as a resonator. The resonance output is output to the outside through a coaxial output terminal (connector) 21 attached to the plate-shaped magnetic core 13.

The resonance frequency of the YIG element 14 is proportional to the magnetic field H. That is, it is proportional to the exciting current I of the coil 19 that produces the magnetic field H. To explain the outline, now, the pot type magnetic core 1
Assuming that the central axis 12 of 1, the outer pot-shaped magnetic core 11 and the plate-shaped magnetic core 13 are connected to form an annular shape, the length of the core is ι, the magnetic field in the core is H, Assuming that the number of turns of the coil is T and the exciting current flowing through the coil is I, the strength H of the magnetic field is H = TI /
become ι. From this equation, it can be seen that the magnetic field strength H is proportional to the number of turns T of the coil and the coil current I, and is semi-proportional to the length ι of the core. In the actual YIG device, the strength H of the magnetic field is smaller than that in the above equation because the YIG element 14 has an air gap.

Coil 1 of the exciting circuit for this YIG device
The resistance of 9 is about 13 Ω (ohm), and the exciting current I is about 500 mA (milliampere) at maximum. Then, the maximum power consumed by this exciter is W = R · I2 = 1
3 × 0.52 = 3.25 (watt), and the average power consumption is about 2 watts. This power consumption becomes heat and is released to the outside. In the past, since the outer shape of this exciter was about the size of a large cup, natural heat radiation was sufficient without doing anything, and there was no fear of heat generation. However, recently, due to the demand for miniaturization of equipment, the demand for miniaturization of YIG devices is also strong, and the size has been about the size of a large egg. Therefore, the surface area of the YIG device has decreased, and in the cylindrical shape as it is, the amount of heat radiation has become smaller than the amount of heat generation only by natural heat radiation. Therefore, only natural heat dissipation without processing YIG
As devices become hotter, the idea of attaching fins to increase the surface area has arisen.

FIG. 3 shows a radiation fin 24 originally conceived. The parts corresponding to those in FIG. 2 are designated by the same reference numerals. FIG.
(A) is a product obtained by processing the pot-shaped magnetic core 11 and using the outer surface of the pot-shaped magnetic core 11 as the radiation fins 24. FIG.
(B) is a product in which an aluminum holder 25 having a radiation fin 24 is attached so as to be in close contact with the pot-shaped magnetic core 11. In any case, the pot-shaped magnetic core 11 is formed as a whole, and in this specification, the pot-shaped magnetic core 11 is included in both.
Say. The heat dissipation fin 24 is provided with a groove substantially perpendicular to the central axis 12 of the pot-shaped magnetic core 11.
This reduces the resistance to the eddy current generated in the clockwise direction by the magnetic field. Easy to process. For the reason.

[0007]

The structure of the conventional heat dissipation fin 24 shown in FIG. 3 is a so-called lamp in which the YIG device is used for sweeping with a ramp-shaped exciting current I like a sweep frequency oscillation or a filter. There was no problem in using it at voltage. However, since the use mode of the YIG device has recently increased in digital communication, the resonance frequency is changed stepwise and the use at a constant frequency without sweeping has increased. Therefore, there has been a demand for operating the YIG device at a stepwise voltage / current to increase the response speed.

As described above, in order to use the magnetic coil at discrete constant frequencies, it is necessary to apply a stepwise voltage / current to the magnetic coil. Moreover, the response speed must be high. However, the magnetic path of the conventional crucible type magnetic core 11 provided with heat radiation fins has irregularities, and the magnetic resistance becomes very large. Therefore, in order to obtain a constant magnetic field at the position of the YIG element 14, it is necessary to increase the exciting current and increase the magnetomotive force, so that the amount of heat generation increases. In addition, there is a problem that it takes a long time to reach a steady state of a constant magnetic field because the magnetic resistance is large. That is, the time constant τ
Since it is large, it has become necessary to reduce τ.

The present invention is for a YIG device in which the exciter of a small YIG device is driven by a relatively small voltage and current, and the generated heat is also radiated by the radiation fins, and the steady state of the constant magnetic field becomes faster than before. The purpose is to provide an exciter.

[0010]

In order to achieve the above object, the present invention has a structure in which a groove of a heat radiation fin of an exciter for a small YIG device is formed substantially parallel to a central axis of a pot-shaped magnetic core to minimize magnetic resistance. And the structure. The surface area of the radiating fins should be the same as that of the conventional radiating fins, and the radiating area should be sufficient. It is better to configure the groove so that it matches the radiating fins of the hollow magnetic core of the plate-shaped magnetic core on which the YIG element is mounted, but it is also possible to use a disk-shaped plate-shaped magnetic core with a maximum radius including the radiating fins. Good. This is because the magnetic reluctance of both is almost the same.

The YIG device exciter having the above structure can maximize the cross-sectional area of the magnetic circuit, and the magnetic circuit length constitutes a closed loop with the shortest distance. Therefore,
Reluctance is minimal. The magnetic resistance ξ is ξ = ι / μA
Given in. Here, ι is the average length of the magnetic circuit, μ is the magnetic permeability, and A is the cross-sectional area of the magnetic circuit. As described above, the magnetic circuit length ι can be minimized and the cross-sectional area A of the magnetic circuit can be maximized, so that the magnetic resistance ξ can be minimized. When the magnetic resistance is reduced, the response of the applied magnetic field to the YIG element becomes faster.

On the other hand, regarding the heat dissipation problem, it is sufficient that the surface area of the heat dissipation fin can be made equal to or larger than that of the conventional one. However, although the resistance to the eddy current due to the magnetic flux is slightly increased, this heat generation amount is negligible compared to the heat generation amount from the coil, so there is little problem with heat dissipation.

As another structure, the direction of the groove of the heat radiation fin may be set at an arbitrary angle of 45 degrees or less with respect to the central axis of the pot-shaped magnetic core. This is because the efficiency of heat dissipation increases when the direction of the groove is determined according to the wind direction inside the device. In this case, the magnetic resistance is slightly increased, but it is very low as compared with the conventional one configured perpendicularly to the central axis, and it is necessary to enhance the heat dissipation effect depending on the wind direction.

Regarding the processing problem, in order to improve the hysteresis, the conventional pot type magnetic core is manufactured by cutting (machining) a 45 nickel alloy containing 45% by weight of Ni and the balance of iron, so-called PB. Was there. In this case, the conventional radiation fin shown in FIG. 3 was easier to fabricate because it was rotated and cut by a machine. However, recently, the magnetic characteristics of the conventional 45
Sendust, which is better than nickel alloy and can be cast, has been developed and made possible by casting. On the contrary, the structure of the present invention is easy to make by the method of manufacturing by sending sendust.

[0015]

FIG. 1 shows an embodiment of the present invention. 2 and 3
The same symbols are attached to the portions corresponding to. FIG. 1 shows a plate-shaped magnetic core 13 of a YIG device exciter and a vase-shaped magnetic core 11.
It is the perspective view removed. The radiating fin 24 has a groove formed in the vase-shaped magnetic core 11 substantially parallel to the central axis 12. Then, as in FIG. 2, a YIG is formed between the central axis 12 of the pot-shaped magnetic core 11 and the plate-shaped magnetic core 13.
A substrate (hybrid integrated circuit) 17 on which elements 14 are arranged
Formed on.

In FIG. 1, the plate-shaped magnetic core 13 is also provided with a radiation fin 24. This is because ventilation is good for heat dissipation and alignment is easy. In terms of the magnetic resistance, the shape of the plate-shaped magnetic core 13 may be a plate-like shape which is fitted to the outermost side of the heat dissipation fin 24 in which the vase-shaped magnetic core 11 is formed.

The outer shape of the pot-shaped magnetic core 11 as viewed from the upper surface may be circular, quadrangular or polygonal except for the uneven portions. That is, the appearance may be cylindrical or polygonal prismatic. It should be suitable for the internal structure of the equipment used.

[0018]

As described in detail above, the YIG device exciter of the present invention has the same power consumption as the coil and the exciting current are the same as the conventional ones even though the YIG device has become smaller. Therefore, the amount of heat generated does not change, and the heat generated by the YIG device is sufficiently radiated by the heat radiation fins that minimize the magnetic resistance. Further, since the magnetic resistance can be minimized, the magnetic response becomes faster, and even if the exciting current is a step-like current, it responds quickly. Therefore, a small YIG device having a fast magnetic response, which can be sufficiently incorporated into a small portable device, can be realized, and its technical effect is great.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a YIG device.

FIG. 3 is a conventional configuration diagram.

[Explanation of symbols]

 10 Magnetic Flux Circuit 11 Vessel-shaped Magnetic Core 12 Center Axis 13 Plate-shaped Magnetic Core 14 YIG Element 15 Support Rod 16 Fixing Tool 17 Substrate (Hybrid Integrated Circuit) 18 Coupling Ring 19 Coil 20 Power Terminal 21 Coaxial Output Terminal (Connector) 24 Radiating Fin 25 Aluminum holder with radiating fins

Claims (2)

[Claims] 1. An open surface of a pot-shaped magnetic core (11) having a central axis (12) is covered with a plate-shaped magnetic core (13), and a tip end surface of the central axis (12) and the plate-shaped magnetic core (11). 13)
A YIG element (14) is disposed between and, and the central axis (1
A YIG device exciter in which an exciting current is applied to a coil (19) wound around (2) to apply a magnetic field to the YIG element (14), wherein a heat-radiating fin having a groove parallel to the central axis (12). An exciter for a YIG device, comprising: a pot-shaped magnetic core (11) having (24). 2. The open surface of the pot-shaped magnetic core (11) having a central axis (12) is covered by a plate-shaped magnetic core (13), and the tip end surface of the central axis (12) and the plate-shaped magnetic core (11). 13)
A YIG element (14) is disposed between and, and the central axis (1
In the YIG device exciter that applies an exciting current to the coil (19) wound around 2) to apply a magnetic field to the YIG element (14), an arbitrary angle of 45 degrees or less with respect to the central axis (12) is used. YI, characterized in that it comprises a crucible-shaped magnetic core (11) having a radiation fin (24) forming an angled groove.
Exciter for G device.