JP2004235812A - Radio relay amplifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio relay amplifier capable of reducing unnecessary noise out of band without degrading a signal being relayed. <P>SOLUTION: The radio relay amplifier for transmitting/relaying a received signal while amplifying comprises a receiving antenna 11, an input side band-pass filter 12 for limiting the band of the received signal, a first amplifier 13 for amplifying the output from the input side band-pass filter 12, a high temperature superconducting band-pass filter 31 for limiting the band of the output from the first amplifier 13, a cryogenic low noise amplifier 32 for amplifying the output from the high temperature superconducting band-pass filter 31, a thermal shield box 33 for thermally shielding the high temperature superconducting band-pass filter 31 and the cryogenic low noise amplifier 32, a means 24 for cooling the thermal shield box 33, a second amplifier 14 for amplifying the output from the cryogenic low noise amplifier 32, an output side band-pass filter 16 for limiting the band of the output from the second amplifier 14, and a transmission antenna 16 for transmitting the output from the output side band-pass filter 16 as a radio wave. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relays and amplifies a received signal in various wireless services such as a mobile phone, a mobile phone, and a wireless paging device in order to prevent a service blind zone in which radio waves from a base station cannot be received, such as behind a mountain, for example. The present invention relates to a wireless relay amplifying device for transmitting data.
[0002]
[Prior art]
First, a conventional wireless relay amplifier will be described. FIG. 3 is a block diagram showing a configuration example of a conventional wireless relay amplification device. As shown in FIG. 3, the wireless relay amplifying apparatus includes a receiving antenna 11, an input-side bandpass filter 12, a first amplifying unit 13, a second amplifying unit 14, an output-side bandpass filter 15, a transmitting antenna 16 Consists of
[0003]
Next, the operation of the conventional wireless relay amplifier shown in FIG. 3 will be described. The receiving antenna 11 is installed at a point where radio waves from a base station can be received, for example, at the top of a mountain. First, the receiving antenna 11 receives a radio wave from a base station and outputs the result to the input-side bandpass filter 12 as a received signal. The received signal is band-limited by the input-side bandpass filter 12, subjected to power amplification by the first amplifier 13, further subjected to power amplification by the second amplifier 14, and output to the output-side bandpass filter 15. The output-side band-pass filter 15 limits the band of the output of the second amplifying unit 14, attenuates harmonics and unnecessary noise outside the band, attenuates unnecessary waves received by the transmission antenna 16, and uses the result as a transmission signal. Output to the transmitting antenna 16. The transmission antenna 16 transmits a transmission signal to the outside as a radio wave. The transmitting antenna 16 is installed at a point where radio waves can be transmitted to a desired area. As described above, the use of the wireless relay amplifying device as shown in FIG. 3 has prevented the occurrence of a service dead zone at a distance of several hundred meters to several kilometers.
[0004]
Next, a description will be given of a configuration example of a conventional wireless relay amplifier including a high-temperature superconducting band filter and a cryogenic low-noise amplifier in place of the input-side band filter 12 shown in FIG. FIG. 4 is a block diagram showing another configuration example of the conventional wireless relay amplification device. The high-temperature superconducting band filter 21 used here has the characteristics that the insertion loss is extremely small and the frequency selectivity is high. Further, the cryogenic low-noise amplifier 22 used here has a feature of suppressing generation of thermal noise. The high-temperature superconducting band-pass filter 21 and the cryogenic low-noise amplifier 22 are sealed in a heat shielding box 23 such as a Dewar bottle, for example, to be thermally shut off. Further, in order to make the high-temperature superconducting band filter 21 and the cryogenic low-noise amplifier 22 in the heat shielding box 23 into a superconducting state, cooling means 24 for cooling the heat shielding box 23 to an extremely low temperature, for example, about several tens of K is provided. Prepare. 4, the same reference numerals as those in FIG. 3 denote the same or corresponding components as those shown in FIG. 3, and a description thereof will be omitted.
[0005]
Next, the operation of the conventional wireless relay amplifier shown in FIG. 4 will be described. The receiving antenna 11 receives a radio wave from the base station and outputs the result to the high-temperature superconducting band filter 21 as a reception signal. The received signal is band-limited by the high-temperature superconducting band-pass filter 21, amplified by the cryogenic low-noise amplifier 22, and output to the first amplifier 13. The output of the cryogenic low-noise amplifier 22 is subjected to the same processing as in FIG. 3 in the first amplifying unit 13, the second amplifying unit 14, the output-side bandpass filter 15, and the transmitting antenna 16, and is transmitted to the outside as radio waves.
[0006]
Here, out-of-band unnecessary noise generated in the wireless relay amplification device will be described. The out-of-band unnecessary noise Nout generated in the wireless relay amplification device is expressed by the following equation (1).
[0007]
Nout = kTBFG (1)
[0008]
In equation (1), k is the Boltzmann constant, T is the absolute temperature, B is the effective bandwidth, F is the noise figure of the wireless relay amplifier, and G is the output of the wireless relay amplifier with respect to the out-of-band attenuation of the bandpass filter 15. Gain ratio. For example, the absolute temperature is 290 K, the effective bandwidth is 4 MHz, the noise figure of the wireless relay amplifying apparatus is 5 dB, the gain of the wireless relay amplifying apparatus is 80 dB, and the out-of-band attenuation of the output side band-pass filter 15 at 500 kHz detuning is 5 dB. Then, the unnecessary noise outside the band becomes -28 dBm (4 MHz).
[0009]
According to the equation (1), in order to reduce unnecessary noise outside the band, the value of G may be reduced by increasing the amount of out-of-band attenuation of the output-side band-pass filter 15.
[0010]
[Problems to be solved by the invention]
To increase the out-of-band attenuation of the output-side bandpass filter 15, it is considered that the bandwidth is narrowed, the number of filter stages is increased, and a high-temperature superconducting filter is used as the output-side bandpass filter 15. However, when the bandwidth is narrowed, there is a problem that a signal to be relayed is deteriorated. Further, when the number of stages of the filter is increased, the loss of the filter is increased, so that the output of the amplifier is increased. As a result, power consumption is increased. When a high-temperature superconducting filter is used as the output-side bandpass filter 15, the attenuation outside the band is 40 dB, which is a sufficient value. However, since the high-temperature superconducting filter generates more distortion than a normal temperature filter. , Can not be used.
[0011]
The present invention has been made in view of the above-described problems, and has as its object to provide a wireless relay amplification device that can reduce unnecessary noise outside a band without deteriorating a signal to be relayed.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a wireless relay amplifying device that relays and amplifies a received signal and transmits the received signal received by the receiving antenna with a receiving antenna that receives a radio wave from a base station. An input-side bandpass filter for band-limiting, a first amplifier for amplifying an output of the input-side bandpass filter, and a high-temperature superconducting bandpass filter using a high-temperature superconductor for band-limiting the output of the first amplifier; A second amplifier for amplifying the output of the high-temperature superconducting bandpass filter, an output-side bandpass filter for band-limiting the output of the second amplifier, and a transmitting antenna for transmitting the output of the output-side bandpass filter as radio waves. It is characterized by having.
[0013]
According to such a configuration, unnecessary noise outside the band can be suppressed without deteriorating the signal to be relayed.
[0014]
Further, in the wireless relay amplifier according to the present invention, a cryogenic low-noise amplifier for amplifying the output of the high-temperature superconducting band filter and outputting the amplified output to the second amplifier is provided.
[0015]
According to such a configuration, the noise of the output of the wireless relay amplification device can be further reduced.
[0016]
In the wireless relay amplifier according to the present invention, the input-side bandpass filter is a high-temperature superconducting bandpass filter.
[0017]
According to such a configuration, unnecessary noise outside the band can be further suppressed.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram illustrating a configuration example of a wireless relay amplification apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, in the present embodiment, a high-temperature superconducting band-pass filter 31 and a cryogenic temperature filter are provided between a first amplifier 13 and a second amplifier 14 in the conventional wireless relay amplifier shown in FIG. The low noise amplifier 32 is inserted. The high-temperature superconducting band-pass filter 31 and the cryogenic low-noise amplifier 32 are sealed in a heat shield box 33 such as a Dewar bottle, for example, and are thermally shut off. Further, a cooling means 24 similar to that of FIG. 4 is provided, and the cooling means 24 is provided with a heat shielding box 33 in order to bring the high-temperature superconducting bandpass filter 31 and the cryogenic low-noise amplifier 32 into a superconducting state. To cool. In FIG. 1, the same reference numerals as those in FIGS. 3 and 4 indicate the same or equivalent objects as those shown in FIGS. 3 and 4, and a description thereof will be omitted.
[0019]
Note that the first amplifier in the present embodiment refers to the first amplifying unit 13 and the second amplifier refers to the second amplifying unit 14.
[0020]
Next, the operation of the wireless relay amplifier of the present invention shown in FIG. 1 will be described. First, the output of the first amplifier 13 is input to the high-temperature superconducting bandpass filter 31. The high-temperature superconducting band filter 31 limits the band of the output of the first amplifying unit 13 and outputs the result to the cryogenic low-noise amplifier 32. The cryogenic low-noise amplifier 32 amplifies the output of the high-temperature superconducting band filter 31 and outputs the result to the second amplifying unit 14. The output of the cryogenic low-noise amplifier 32 is subjected to the same processing as in FIG. 3 in the second amplifying unit 14, the output-side bandpass filter 15, and the transmitting antenna 16, and is transmitted as radio waves to the outside.
[0021]
Here, out-of-band unnecessary noises generated in the conventional wireless relay amplifier shown in FIG. 3 and the wireless relay amplifier of the present invention shown in FIG. 1 are compared. First, in the conventional wireless relay amplifying apparatus shown in FIG. 3, a gain against unnecessary noise outside the band will be considered. Assuming that the gain of the first amplifier 13 is G13, the noise figure of the first amplifier 13 is F13, the gain of the second amplifier 14 is G14, and the noise figure of the second amplifier 14 is F14, The gain G1 of the device is expressed by the following expression (2), and the noise figure F1 of the conventional wireless relay amplifying device is expressed by the following expression (3).
[0022]
G1 = G13 × G14 (2)
[0023]
F1 = F13 + (F14-1) / G13 (3)
[0024]
Next, in the wireless relay amplifying device of the present invention shown in FIG. 1, the gain against unnecessary noise outside the band will be considered. If the amount of out-of-band attenuation of the high-temperature superconducting filter 31 is sufficient, unnecessary noise before the high-temperature superconducting filter 31 becomes invisible. For example, if the noise figure before the high-temperature superconducting filter 31 is F0, the unnecessary noise before the high-temperature superconducting filter 31 is Nout0 = kTB (F0) (G13). When the out-of-band attenuation of the high-temperature superconducting filter 31 is L31, the unnecessary noise after the high-temperature superconducting filter 31 is Nout01 = kTB (F0) (G13 / L31). Therefore, if L31 >> G13, Nout01 becomes small, and unnecessary noise before the high-temperature superconducting filter 31 becomes a negligible level.
[0025]
Assuming that the gain of the cryogenic low-noise amplifier 32 is G32 and the noise figure of the cryogenic low-noise amplifier 32 is F32, the gain G2 of the wireless relay amplifying device of the present invention is expressed by the following equation (4). The noise figure F2 of the relay amplifier is represented by the following equation (5).
[0026]
G2 = G33 × G14 (4)
[0027]
F2 ≒ F32 + (F14-1) / G32 (5)
[0028]
Here, the gain G1 ′ = G13 × G14 for the signal in the band in the conventional wireless relay amplifier is equal to the gain G2 ′ = G13 × G32 × G14 for the signal in the band in the wireless relay amplifier of the present invention. I do. At this time, although F1 and F2 are not significantly different, the gain G2 for unnecessary noise outside the band in the wireless relay amplifying device of the present invention is equal to the value obtained by removing G13 from G2 'as described above. Is smaller than the gain G1 for unnecessary noise outside the band. Therefore, the wireless relay amplifying device of the present invention shown in FIG. 1 can suppress out-of-band unnecessary noise as compared with the conventional wireless relay amplifying device shown in FIG.
[0029]
In the present embodiment, an example in which the cryogenic low-noise amplifier 32 is used together with the high-temperature superconducting band filter 31 has been described, but a normal amplifier may be used instead of the cryogenic low-noise amplifier 32.
[0030]
Embodiment 2 FIG.
FIG. 2 is a block diagram illustrating a configuration example of a wireless relay amplification apparatus according to Embodiment 2 of the present invention. As shown in FIG. 2, in the present embodiment, a high-temperature superconducting band-pass filter 21 and a cryogenic low-noise amplifier 22 are provided instead of the input-side band-pass filter 12 in the wireless relay amplifier of the present invention shown in FIG. . The high-temperature superconducting band-pass filter 21 and the cryogenic low-noise amplifier 22, and the high-temperature superconducting band-pass filter 31 and the cryogenic low-noise amplifier 32 are sealed in a heat shield box 53 such as a Dewar bottle, for example, and are thermally shut off. In addition, a cooling means 24 similar to that of the first embodiment is provided, and the cooling means 24 includes a high-temperature superconducting band filter 21 and a cryogenic low-noise amplifier 22 and a high-temperature superconducting band filter 31 and a cryogenic low-temperature In order to bring the noise amplifier 32 into a superconductive state, the heat shield box 53 is cooled. 2, the same reference numerals as those in FIGS. 1 and 4 denote the same or corresponding objects as those shown in FIGS. 1 and 4, and a description thereof will be omitted.
[0031]
In the present embodiment, unnecessary noise outside the band can be suppressed as compared with the conventional wireless relay amplifier, and the high-temperature superconducting band filter 21 and the cryogenic low- By using the noise amplifier 22, unnecessary noise outside the band can be further suppressed.
[0032]
【The invention's effect】
As described in detail above, according to the present invention, there is an effect that it is possible to provide a wireless relay amplifying device capable of reducing unnecessary noise outside a band without deteriorating a signal to be relayed.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration example of a wireless relay amplification apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a block diagram illustrating a configuration example of a wireless relay amplification device according to a second embodiment of the present invention.
FIG. 3 is a block diagram illustrating a configuration example of a conventional wireless relay amplification device.
FIG. 4 is a block diagram illustrating another configuration example of a conventional wireless relay amplification device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 receiving antenna, 12 input side band filter, 13 1st amplifier, 14 2nd amplifier, 15 output side band filter, 16 transmitting antenna, 21, 31 high temperature superconducting band filter, 22, 32 cryogenic low noise amplifier, 33, 53 heat shielding box, 24 cooling means.

Claims (3)

In a wireless relay amplifying device for relay-amplifying and transmitting a received signal,
A receiving antenna for receiving radio waves from the base station;
An input-side bandpass filter for band-limiting a reception signal received by the reception antenna,
A first amplifier for amplifying the output of the input band-pass filter;
A high-temperature superconducting bandpass filter using a high-temperature superconductor for band-limiting the output of the first amplifier;
A second amplifier for amplifying the output of the high-temperature superconducting bandpass filter;
An output-side band-pass filter for band-limiting the output of the second amplifier;
A transmission antenna for transmitting an output of the output band-pass filter as a radio wave. The wireless relay amplifying device according to claim 1,
A wireless relay amplifying device comprising a cryogenic low-noise amplifier for amplifying an output of the high-temperature superconducting band filter and outputting the amplified output to the second amplifier. The wireless relay amplifying device according to claim 1 or 2,
The input-side bandpass filter is a high-temperature superconducting bandpass filter.

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