JP3392367B2 - Non-contact type high frequency transmission device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency transmission means which is connected to a superconducting filter circuit existing at a low temperature (a temperature of about 70K) and kept in a vacuum in a non-contact manner.

[0002]

2. Description of the Related Art Conventionally, in a high frequency circuit of a wireless communication device, a radio signal is generally received by an antenna, a duplexer circuit separates the transmission signal and the reception signal, and then a bandpass filter is used to cut the reception signal to eliminate the excess frequency. The signal is processed by amplifying it with an amplifier. In addition, recently, in a base station of a mobile communication system, in order to be able to receive a weak radio wave, a bandpass filter used there is a high-performance filter,
For example, a superconducting filter (High Tc (critical temperature) Supercondu
cting Filter: A technology to replace it with HTS filter) is under consideration. In this case, for example, a superconducting filter needs to be housed in a vacuum heat insulating container to maintain a low temperature state, and the coaxial cable used for the interface of the filter is also required to suppress heat conduction.

In this case, since the means for electrically connecting the HTS filter circuit and the circuit outside the vacuum heat insulating container keep the temperature at a low temperature with a small cooling capacity, the loss of the received power must be low, and the heat Insulation is good to prevent inflow, and downsizing is required as a measure against radiant heat.

By the way, under such conditions, it is first considered that the means for electrically connecting uses capacitive coupling capable of transmitting a high frequency signal in a non-contact manner. However, in order to achieve low loss by this method, it is necessary to increase the capacitive coupling value, and it is indispensable to expand the coupling part (opposing area) or narrow the coupling gap.
However, if a non-contact high frequency (capacitive coupling type) transmission device is created by such a method, the following problems will occur. (1) Assuming commercial facilities, this high-frequency transmission device inevitably increases in size. If so, radiant heat becomes large, and separate measures are required. (2) Increasing the capacitive coupling value narrows the coupling gap. Positioning becomes difficult during assembly. If they come into contact, a large amount of heat inflow and a large change in electrical performance will occur.

The prior art had some success in transmitting high-frequency signals by capacitive coupling, but this was the case for a small-scale test facility, and there were at least two problems described above. There was found. Especially when trying to move from a test facility to a commercial scale facility, difficult challenges due to facility scale are likely to occur.

[0006]

Therefore, it is an object of the present invention to develop a high-frequency signal transmission device which is small in size and easy to position during assembly.

Basically, it is necessary to follow the principle of capacitive coupling and to eliminate the problems of precision in manufacturing members constituting the line and precision in assembling. An object of the present invention is to solve such conventional problems.

[0008]

The inventor of the present invention can transmit a high-frequency signal in a resonance state in a non-contact state, and need not consider the capacitance adjustment as compared with the case of capacitive coupling. As a result of intensive study on the development of the resonator, focusing on the point, a practical signal transmitting means could be found in the coaxial resonant element whose shape is relatively similar to the capacitive coupling device, and the present invention was completed.

In order to achieve the above-mentioned object, the invention according to claim 1 fits in a space formed between a first inner conductor, a first outer conductor forming a coaxial line with the first inner conductor, and a space formed between the both conductors. A double cylindrical resonator including a second inner conductor and a second outer conductor, wherein one ends of the first inner conductor and the first outer conductor are filled with a dielectric, The end is an open surface, one end between the second inner conductor and the second outer conductor is also filled with a dielectric, and the other end forms an open surface, and the cylinder length of the resonator is used. Frequency 4
It is a non-contact type high frequency transmission device having a length that satisfies one-half wavelength.

The invention according to claim 2 is the first invention.
The inner conductor and the first outer conductor form a part of a coaxial cable, and a resonator composed of the second inner conductor and the second outer conductor is incorporated therein, and one end of the resonator is provided with a predetermined superconducting filter circuit. It is characterized by being connected to.

Further, the invention described in claim 3 is the first aspect.
The inner conductor 11, the first outer conductor 12 forming a coaxial line together with the inner conductor 11, the second inner conductor 21 having a double-cylindrical shape, which is filled in the space formed between the two conductors, and the second outer conductor 2.
2, the first inner conductor 11 and the first outer conductor 12 have one end sealed with a dielectric 31 and the other end open, and the second inner conductor 21 and the second outer conductor 22 are connected to each other. One end is sealed by a dielectric 32 and the other end is opened to form a cavity resonator, and an airtight adapter for a vacuum insulation container at room temperature and a superconducting filter 43 in a vacuum insulation container at low temperature are formed.
It is a superconducting filter system characterized in that it is electrically connected to and is thermally cut off.

According to the invention disclosed in claims 1 to 3, the first inner conductor and the first outer conductor form a part of a coaxial cable, and the second inner conductor and the second outer conductor are formed in the coaxial cable. If a λ / 4 resonator formed of a λ / 4 resonator is incorporated and one end of the λ / 4 resonator is connected to a predetermined superconducting filter circuit, heat conduction to the superconducting filter circuit via a coaxial line can be blocked. There is an advantage that the problem of being able to be solved can be completely solved, and furthermore, it can be easily carried out without requiring skill in manufacturing and assembling each member of the transmission device.

The device of the present invention can be applied to, for example, an interface of a superconducting filter system provided in a base station of a mobile communication system.

[0014]

In the cavity resonator formed of the second inner conductor and the second outer conductor, the length of the cylindrical shape need only be set to 1/4 of the frequency used, regardless of the capacitance value. the non-contact type radio frequency transmission device utilizes Do that resonance and low loss with a quarter wavelength. Therefore, there is no need to expand the coupling portion or the coupling gap, and there is no restriction from the requirements specific to the capacitive coupler.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a coaxial resonator that constitutes a high-frequency signal transmission device according to the present invention.

In FIG. 1, reference numeral 11 is a first inner conductor forming a first line in the axial direction, and 12 is a first inner conductor 1.
1 is a cylindrical first outer conductor that forms a coaxial two-wire line (coaxial line) together with 1. These first inner conductor 11 and first
In the space with the outer conductor 12, a double-cylindrical resonator having one open end formed of the second inner conductor 21 and the second outer conductor 22 is formed, and in the space, the inner surface of the first outer conductor is formed. It is fitted so that it does not touch. Further, the second inner conductor 21 is separated from the first inner conductor 11 in a non-contact state,
The first inner conductor 11 is covered.

The length of the cylinder formed by the second inner conductor 21 and the second outer conductor 22 is 4 times the frequency used.
It is adjusted so as to be one-half and a λ / 4 resonance element is obtained. In this case, it is not necessary to be caught by the capacitance value formed by the second inner conductor and the second outer conductor. The resonance is determined by the length of the second double cylinder, and when resonance occurs, the high frequency signal is transmitted with low loss.

The high frequency transmission device of the present invention can be used in, for example, the superconducting filter system disclosed in FIG.

In FIG. 2, the first inner conductor 11 and the first inner conductor 11
The outer conductor 12 is a part of the interface 44 in a predetermined superconducting filter circuit, and is connected to, for example, an airtight adapter of a vacuum insulation container. Second inner conductor 21
The diameters of the second outer conductor 22 and the second outer conductor 22 are set so as to have a predetermined characteristic impedance, and are also a part of the interface 44. Then, it is interposed between a microstrip line (not shown in detail) forming a predetermined superconducting filter circuit and is connected to, for example, a stripline converter. Further, all of them are provided in the vacuum heat insulating container 41, and the superconducting filter 43 is in a state where there is no heat transfer due to convection of air or the like or heat conduction through a conductor. The high-frequency transmission device of the present invention has no difference in electrical and thermal performance even when the airtight adapter and the superconducting filter are connected in opposite directions. If they are arranged at both ends, the heat conduction from the vacuum insulation container can be completely cut off.

According to FIG. 2, the filter for attenuating the unwanted high output signal received from the antenna before sending it to the superconducting filter is replaced with a part of the interface 44, thereby eliminating the specific frequency attenuation filter which is a loss factor. You can Further, the first inner conductor 11 and the first outer conductor 12 form a part of the coaxial cable, and the second inner conductor 21 and the second outer conductor 22 are incorporated in the coaxial cable, and one end thereof is a predetermined superconducting filter. Because it connects to the circuit,
The conduction of heat to the superconducting filter circuit can be reliably cut off, and the filter characteristics can be improved.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the transmission device of FIG. 1, the first and second outer conductors and the first and second inner conductors are capacitively coupled. At that time, the cylinder lengths of the second inner and outer conductors (resonators) are as shown by the arrows in FIG. 1, but the resonance frequency is 2 GHz.
Set the tube length to 37.5 mm to match
When the pass characteristics were measured at frequencies from GHz to 3 GHz, the signal transfer characteristics shown in FIG. 3 were obtained. It was found from the graph that the amount of attenuation decreases in the 2 GHz band set, and if it deviates from it, the amount of attenuation increases and unnecessary high output signals can be attenuated, so that the high-frequency transmission device of the present invention can be used without any trouble.

In the present embodiment, the high frequency transmission device is applied to the interface of the superconducting filter system, but the present invention is not limited to this, and a high frequency signal is transmitted using a coaxial line. It is needless to say that it can be widely applied to cases and the operating temperature range is not limited to the low temperature range. Further, since the capacitive coupling portion is not in contact, it can be used also when the first inner conductor 11 and the first outer conductor 12 rotate relative to the second inner conductor 21 and the second outer conductor 22. it can.

[0023]

According to the present invention, these claims 1 to 3
According to the invention disclosed in, the first inner conductor and the first outer conductor form a part of a coaxial cable, and λ is formed from the second inner conductor and the second outer conductor.
If a / 4 resonator is incorporated and one end of the / 4 resonator is connected to a predetermined superconducting filter circuit, it is possible to block heat conduction to the superconducting filter circuit via a coaxial line. There is an advantage that it can be solved completely and can be easily carried out without requiring skill in manufacturing and assembling each member of the transmission device.

Further, the first inner conductor and the first outer conductor constitute a part of the coaxial cable, and the second inner conductor and the second outer conductor are incorporated therein, and either one of them is connected to a predetermined superconducting filter circuit. If it is connected to the connected converter, the heat conduction to the superconducting filter circuit can be reliably cut off by resonance.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining a high frequency transmission device of the present invention.

FIG. 2 is a schematic view for explaining a system using a superconducting filter including the high frequency transmission device of the present invention.

FIG. 3 is a graph showing a signal transfer characteristic of a high frequency transfer device of the present invention in a 2 GHz band.

[Explanation of symbols]

11 First inner conductor 12 First outer conductor 21 Second inner conductor 22 Second outer conductor 31 Dielectric 32 dielectric 41 Vacuum insulation container 43 Superconducting filter 44 interface

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Kubota               Aichi Prefecture Nisshin City Yoneshinomachi Minamiyama 500-1               Mobile Communications Advanced Technology Laboratory Co., Ltd.                (56) Reference JP-A-6-188604 (JP, A)                 Japanese Patent Publication Sho 40-5651 (JP, B1)

Claims (3)

(57) [Claims] 1. A first inner conductor, a first outer conductor which forms a coaxial line together with the first inner conductor, a second inner conductor which opposes the first inner conductor between the two conductors so as to be capable of capacitive coupling, and the second inner conductor. And a second outer conductor facing the first outer conductor so as to be capable of capacitive coupling between the first outer conductor and the first outer conductor, one end of the first inner conductor and the first outer conductor is filled with a dielectric, and the other end is It is an open surface, and one end is also filled with a dielectric material between the second inner conductor and the second outer conductor, and the other end forms an open surface, and the cylinder length of the second inner conductor and the second outer conductor is used. A non-contact type high-frequency transmission device comprising a λ / 4 resonator so as to satisfy a quarter wavelength (wavelength: λ) of the frequency to be set. 2. The first inner conductor and the first outer conductor constitute a part of a coaxial cable, and the second inner conductor and the second outer conductor are incorporated in the coaxial cable, and one end of which is predetermined. The non-contact type high frequency transmission device according to claim 1, which is connected to a superconducting filter circuit. 3. A first inner conductor, a first outer conductor forming a coaxial line together with the first inner conductor, a second inner conductor and a second outer member which are fitted in a space formed between the two conductors and resonately oppose each other. And a double-cylindrical resonator including a conductor, wherein one end of the first inner conductor and the first outer conductor is filled with a dielectric and the other end is opened. One end between the second inner conductor and the second outer conductor is filled with a dielectric material, and the other end is opened, and a λ / 4 having a predetermined tube length is provided.
A superconducting filter system which forms a resonator, electrically connects the airtight adapter of the vacuum insulating container at room temperature to the superconducting filter 43 in the vacuum insulating container at low temperature, and is thermally insulated. .