KR19980084008A - High frequency signal transmitter - Google Patents

Abstract

The present invention is a transmission in a high frequency signal transmission apparatus for transmitting a high frequency radio signal through a coaxial cable between an outdoor antenna for transmitting and receiving a high frequency radio signal and an indoor radio communication device or a plurality of radio communication devices that are remotely spaced apart. In order to increase the efficiency of the furnace, according to the present invention, the high frequency signal transmission comprising a frequency down conversion means for converting the desired high frequency signal to reduce the transmission path attenuation before applying the high frequency signal to the coaxial cable An apparatus is provided.

Description

High frequency signal transmitter

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio transmission technology, and more particularly, to an apparatus for transmitting high frequency signals between an outdoor antenna for transmission and reception and indoor radio communication equipment or a plurality of radio communication devices spaced apart from each other.

As shown in FIG. 1, the conventional high frequency signal transmission apparatus uses a coaxial cable 20 when the wireless communication equipment 30 and the antenna 10 are remotely spaced apart in the communication using a high frequency radio signal. Connect. At this time, when the carrier frequency is high, for example, 800 MHz for a mobile phone, 1.8 GHz for a personal mobile communication (PCS), 4-6 GHz for a microwave, etc. are used. The attenuation is so severe that the intensity of the radio wave input to the radio communication device 30 is much lower than that of the radio wave received at the actual antenna 10, thereby deteriorating the reception sensitivity of the entire radio communication device. In addition, if the distance to the antenna is long at the time of transmission, more than necessary power amplifier output is needed because of line attenuation.

Accordingly, in the related art, an optical cable may be used instead of a coaxial cable, but since the optical cable is expensive, there is a problem in that the unit cost of the high frequency signal transmission apparatus using the same increases. There is a problem that the value becomes expensive and the cost of the high frequency signal transmission device becomes expensive.

Accordingly, it is an object of the present invention to provide a high frequency signal transmission apparatus capable of improving efficiency by improving losses generated in a transmission path at low cost when using wireless communication equipment.

1 is a block diagram showing an example of a conventional high frequency signal transmission apparatus.

2 is a block diagram of a high frequency signal transmission apparatus between an outdoor antenna and indoor wireless communication equipment in the case of receiving according to the first embodiment of the present invention.

3 is a block diagram showing a down converter in a detailed block diagram in the high frequency signal transmission device shown in FIG.

4 is a block diagram of a high frequency signal transmission apparatus between an outdoor antenna and indoor wireless communication equipment in the case of transmitting according to the second embodiment of the present invention.

5 is a block diagram of a high frequency signal transmission apparatus between a plurality of radio communication equipment spaced apart from each other according to a third embodiment of the present invention.

* Explanation of symbols on the main parts of the drawings *

100... antenna

300, 302, 305, 310... Wireless communication equipment

150, 152, 150A, 150B... Downconverter

200, 220, 230A, 230B... Coaxial cable

250, 250A, 250B... Up-converter

According to a first embodiment of the present invention, a high frequency signal transmission apparatus for transmitting a high frequency radio signal received through a coaxial cable between an outdoor antenna for receiving a high frequency radio signal and an indoor radio communication device, the reception at the antenna Provided is a high frequency signal transmission device comprising frequency downconverting means for converting a desired high frequency signal to a desired downlink frequency in order to reduce transmission path attenuation before applying the coaxial cable.

The high frequency signal transmitting apparatus according to the first embodiment described above preferably further includes frequency upconverting means for converting a signal transmitted by the coaxial cable to an uplink frequency before inputting the signal to the wireless communication equipment.

Preferably, the frequency down conversion means described above comprises: a first band pass filter for selecting and outputting a desired radio frequency from a high frequency signal received by an antenna; Reference clock supply means for supplying a reference clock; Mixing means for inputting the radio frequency selected by the first band pass filter and the reference clock to output an intermediate frequency which is a difference signal between the selected radio frequency and the reference clock signal; And a second bandpass filter for selecting a desired downlink frequency from among intermediate frequency outputs of the mixing means.

In addition, according to the second embodiment of the present invention, a high frequency signal transmission for transmitting the high frequency radio signal through a coaxial cable between the indoor wireless communication equipment and the outdoor antenna for transmitting the high frequency radio signal output from the wireless communication equipment An apparatus comprising: a frequency downconverting means for converting a high frequency radio signal output from a wireless communication device into a desired downlink frequency to reduce attenuation of a transmission path before applying a coaxial cable to a high frequency signal transmitting apparatus; do.

The high frequency signal transmitting apparatus according to the second embodiment described above preferably further includes frequency upconverting means for converting a signal transmitted by the coaxial cable to an uplink frequency before inputting the signal to the antenna.

Preferably, the frequency upconverting means described above comprises: a first bandpass filter for selecting and outputting a desired frequency from downlink frequency signals output by the frequency downconverting means; Reference clock supply means for supplying a reference clock; Mixing means for inputting the frequency selected by the first band pass filter and the reference clock and outputting a radio frequency which is a sum signal of the selected frequency and the reference clock signal; And a second bandpass filter for selecting a desired upstream frequency of the output of the mixing means.

In addition, according to the third embodiment of the present invention, in the high-frequency signal transmission device for transmitting a high-frequency wireless data signal of each other via a coaxial cable between a plurality of remotely spaced wireless communication equipment, the high frequency output of the first wireless communication equipment A first frequency downconverting means for converting a high frequency output signal of the first radiocommunication device to a downlink frequency to reduce attenuation of the transmission path before transmitting the signal to the second radiocommunication device via the first coaxial cable; An apparatus for transmitting high frequency signals is provided.

Preferably, the high frequency signal transmission apparatus according to the third embodiment of the present invention preferably converts a signal converted into a downlink frequency by a first frequency downconverting means and transmitted through a first coaxial cable to the high frequency output signal of a first wireless communication device. And first frequency up-converting means for frequency up-converting to.

In addition, the high frequency signal transmission apparatus according to the third embodiment described above, preferably, when transmitting the high frequency output signal of the second radio communication device to the first radio communication device, the high frequency output signal of the second radio communication device is the second coaxial. And second frequency downconverting means for converting to a downlink frequency to reduce attenuation of the transmission path prior to transmission over the cable.

In addition, the high frequency signal transmission apparatus according to the third embodiment described above, preferably, the high frequency output of the second radio communication device converts the signal converted to the down frequency by the second frequency downconverting means and transmitted through the second coaxial cable. And second frequency upconverting means for frequency upconverting the signal.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, a case of transmitting a high frequency radio signal received through an outdoor antenna to an indoor wireless communication device will be described.

2 is a block diagram of a high frequency signal transmission apparatus between an outdoor antenna and an indoor wireless communication device in the case of receiving according to the first embodiment of the present invention. The high frequency signal transmitting apparatus shown in FIG. 2 includes an antenna 100 installed outdoors, a down converter 200 connected to an output side of the antenna 100 to convert an input frequency into a desired downward frequency, and an input terminal. Coaxial cable 200 which is connected to the down-converter 150 and outputs the above-mentioned downlink frequency inputted to this input side terminal through an output side terminal, and frequency which is output from this output side terminal connected to the output side terminal of the coaxial cable 200. It consists of a wireless communication device 300 for signal processing. In this case, using the down converter 150 attached to the antenna 100 to reduce the frequency of the radio wave to a downlink frequency received from the antenna 100 installed outdoors to the wireless communication device 300 through the coaxial cable 200 By transmitting, the loss in coaxial cable during transmission can be improved.

TABLE 1

Loss of coaxial cable according to frequency

Cable type Cable Impedance (Z ₀ ) 0.5 1.0 3.0 5.0 10.0 12.0 18.0 Frequency (GHz) RG-8A 52 Ω 4.6 9 19 28 47 - - Attenuation (dB / 100ft) RG-9A 51Ω 4.6 9 19 28 47 - - RG-58A 52 Ω 11 20 41 - - - - RG-59A 75Ω 6.7 11.5 22.5 41 - - - RG-62A 93Ω 5.2 8.5 18.4 29.5 - - - RG-174 50 Ω 17.5 31 64.3 97 185 - - RG-196 50 Ω 27.5 45 78 115 172 - - RG-214 50 Ω 4.6 9 19 28 47 - - RG-223 50 Ω 8.8 16.5 36 51 90 - - 0.085_semirigid 50 Ω 11.6 18.7 34 46 73.2 84 115 0.141_semirigid 50 Ω 7.2 11.6 21.5 28.5 44.5 51 68 0.250_semirigid 50 Ω 4.3 7.3 14 18.9 29 33 -

As an example, referring to Table 1 above, when the cable type is RG-214 and the antenna input frequency is 3 kHz, the attenuation in the conventional high frequency signal transmission apparatus using a coaxial cable as the transmission path shown in FIG. When the input high frequency signal is down-converted to a frequency of, for example, 0.5 kHz through the down converter 150 according to the first embodiment of the present invention shown in FIG. Only 100ft occurs.

FIG. 3 is a block diagram showing a down converter in a detailed block diagram in the high frequency signal transmission device shown in FIG.

Referring to FIG. 3, the first embodiment of the present invention will be described in more detail by using a first filter 62 which is a band pass filter through which a high frequency signal input to the antenna 100 passes a desired frequency band. To output a radio frequency (RF) signal, which is a filtering output, to the mixer 64. The mixer is fed to a reference clock supply 66 and a radio frequency (RF) signal that is the output of the first filter 62 to frequency convert the radio frequency (RF) that has passed through the first filter 62 to a lower frequency. The reference clock RC is inputted to output an intermediate frequency IF signal which is a difference signal between the radio frequency RF signal and the reference clock RC. Since this intermediate frequency (IF) signal may contain noise during mixing, the intermediate frequency (IF) signal is amplified by the amplifier 68 and then the desired downlink frequency by the second filter 70 which is a bandpass filter. To obtain the frequency downconverted output. The frequency down-converted output is transmitted through the coaxial cable 200, and the inverse of the frequency down-conversion through the up-converter 250 (the up-converter will be described later with reference to FIG. 4) connected to the output side of the coaxial cable. The frequency up-conversion is performed, and the frequency up-conversion output is input to the wireless communication device 300.

Next, a case of transmitting the output from the indoor wireless communication equipment through the outdoor antenna will be described.

4 is a block diagram of a high frequency signal transmission apparatus between an outdoor antenna and indoor wireless communication equipment in the case of transmitting according to the second embodiment of the present invention.

The high frequency signal transmission device shown in FIG. 4 is installed indoors and connected to the output side of the radio communication equipment 302 and the radio communication equipment 302 for outputting a predetermined high frequency radio signal, and converts the input frequency into a desired downlink frequency. By the coaxial cable 220 and the coaxial cable 220 which are connected to the output side of the down converter 152, the down-converter 152 for outputting the An upconverter 250 converts the transmitted signal back to an uplink frequency and outputs the output signal, and an antenna 102 radiating the output frequency of the upconverter 250.

The down-converter 152 shown in FIG. 4 is connected to the down-converter 150 shown in FIG. 3 except that the output of the wireless communication device 302 is input instead of the radio wave received by the antenna 100 on the input side. Since the function is the same, description thereof is omitted to avoid duplication.

Next, the upconverter 250 of FIG. 4 is explained in full detail.

Desired intermediate frequency (IF) signal using a third filter 82, which is a bandpass filter for selecting and outputting a desired frequency among down signals output by the down converter 152 transmitted through the coaxial cable 220 Is output to the mixer 84. Mixer 84 converts the intermediate frequency IF, which is the output of third filter 82, to a higher frequency, and the reference clock supply device and the intermediate frequency IF, which is the output of third filter 82, 86) A reference clock RC is inputted from the control panel to output a radio frequency (RF) signal, which is a sum signal of the intermediate frequency IF signal and the reference clock RC. Since the noise may have been mixed in the radio frequency (RF) signal, a frequency up-converted output of the radio frequency (RF) signal is obtained through a fourth filter 88, which is a bandpass filter, at a desired uplink frequency. Amplify through amplifier 90 and transmit to antenna 102.

In order to compare the high frequency signal transmission apparatus according to the second embodiment of the present invention by the above-described process and the conventional high frequency signal transmission apparatus, for example, referring also to Table 1, the cable type is RG-214. And the output of the radio communication equipment 302 is 3 mW, the attenuation is 28 mW / 100 ft in the conventional high frequency signal transmission device using the coaxial cable as the transmission path. However, in the second embodiment of the present invention shown in FIG. Accordingly, when the output of the wireless communication device 302 is down-converted to a frequency of, for example, 0.5 kHz through the down converter 152, only 4.6 kHz / 100 ft is generated. In addition, since the transmission loss in the coaxial cable is compensated when the frequency is down-converted as described above, for example, when the loss is compensated for about 20 kHz in the coaxial cable, the transmission of the wireless communication device 302 that was transmitted using the existing 100 W was performed. The same effect can be achieved by radiating the output at 1W.

Next, a high frequency signal transmission apparatus for transmitting a high frequency wireless data signal to each other through a coaxial cable between a plurality of remotely spaced wireless communication equipment will be described.

5 is a block diagram of a high frequency signal transmission apparatus between a plurality of radio communication equipment that is spaced apart from each other according to a third embodiment of the present invention. The high frequency signal transmission apparatus according to the third embodiment shown in FIG. 5 shows the use of a down converter in both transmission and reception directions.

The high frequency signal transmission apparatus according to the third embodiment transmits a high frequency output signal of the wireless communication device 1 305 when the wireless communication device 1 305 transmits the high frequency output signal to the wireless communication device 2 310. The downcoverer 150A converts to a downlink frequency to reduce the attenuation during transmission through the coaxial cable 230A before transmitting through the downlink, and the down converter 150A converts the downlink frequency to a downlink frequency and coaxial cable 230A. Up-converter 250A for up-converting the signal transmitted through the high-frequency output signal of the wireless communication device 1 (305) and outputting to the wireless communication device 2 (310). In addition, the high frequency signal transmission apparatus according to the third embodiment transmits a high frequency output signal of the wireless communication device 2 310 when the wireless communication device 2 310 transmits a high frequency output signal to the wireless communication device 1 305. The downcoverer 150B converts the downlink frequency to reduce the attenuation during transmission through the coaxial cable 230B before transmitting through the 230B, and the downconverter 150B converts the downlink frequency to the downlink frequency so that the coaxial cable ( Upconverter 250B for converting the signal transmitted through the 230B back to the high-frequency output signal of the wireless communication device 2 (310) to output to the wireless communication device 1 (310). The downconverter 150A and the downconverter 150B have the same structure as the downconverter 150 of FIG. 3, respectively, and the upconverter 250A and the upconverter 250B are respectively the upconverter 250 and the upconverter 250 of FIG. 4. Since the structure is the same, duplicate descriptions thereof will be omitted.

By configuring as described above, the high frequency signal transmission apparatus according to the third embodiment of the present invention transmits the high frequency wireless data signals of each other in both directions via a coaxial cable between a plurality of radio communication equipment that are spaced apart from each other on the transmission path. Cable loss can be improved.

According to the present invention, it is possible to improve the transmission efficiency by improving the loss generated in the transmission path at low cost when using the wireless communication equipment.

Claims (10)

In the high frequency signal transmission apparatus for transmitting the high frequency radio signal received through a coaxial cable between an outdoor antenna for receiving a high frequency radio signal and indoor wireless communication equipment, And a frequency downconverting means for converting a high frequency signal received by the antenna into a desired downlink frequency in order to reduce attenuation of a transmission path before applying the high frequency signal to the coaxial cable. The method of claim 1, And a frequency up-converting means for converting the signal transmitted by the coaxial cable to an uplink frequency before inputting the signal to the wireless communication equipment. The method according to claim 1 or 2, The frequency downconverting means comprises: a first bandpass filter for selecting and outputting a desired radio frequency from a high frequency signal received by the antenna; A reference clock supply means for supplying a reference clock; Mixing means for inputting the radio frequency selected by the first band pass filter and the reference clock to output an intermediate frequency which is a difference signal between the selected radio frequency and the reference clock signal; And a second bandpass filter for selecting the desired downlink frequency among the intermediate frequency outputs of the mixing means. In the high frequency signal transmission device for transmitting the high frequency radio signal through a coaxial cable between the indoor radio communication equipment and the outdoor antenna for transmitting the high frequency radio signal output from the radio communication device, And a frequency downconverting means for converting the high frequency radio signal output from the radio communication equipment into a desired downlink frequency to reduce transmission attenuation before applying the coaxial cable to the coaxial cable. The method of claim 4, wherein And a frequency upconverting means for converting a signal transmitted by the coaxial cable to an uplink frequency before inputting the signal to the antenna. The method of claim 5, The frequency up-converting means comprises: a first band pass filter for selecting and outputting a desired frequency from down-frequency signals output by the frequency down-converting means; A reference clock supply means for supplying a reference clock; Mixing means for inputting the frequency selected by the first band pass filter and the reference clock to output a radio frequency that is a sum signal of the selected frequency and the reference clock signal; And a second bandpass filter for selecting the desired uplink frequency from the output of the mixing means. In the high frequency signal transmission apparatus for transmitting a high frequency wireless data signal of each other through a coaxial cable between a plurality of remotely spaced wireless communication equipment, When transmitting the high frequency output signal of the first radio communication device to the second radio communication device, converting the high frequency output signal of the first radio communication device to the downlink frequency to lower the attenuation of the transmission path before transmitting through the first coaxial cable. And a first frequency downconverting means. The method of claim 7, wherein And a first frequency upconverting means for converting the signal, which is converted into the downlink frequency by the first frequency downconverting means and transmitted through the first coaxial cable, into the high frequency output signal of the first radio communication equipment. High frequency signal transmission apparatus comprising a. The method according to claim 7 or 8, When transmitting the high frequency output signal of the second radio communication device to the first radio communication device, converting the high frequency output signal of the second radio communication device to the downlink frequency to lower the attenuation of the transmission path before transmitting through the second coaxial cable. And a second frequency downconverting means. The method of claim 9, And second frequency upconverting means for converting the signal, which is converted into the downlink frequency by the second frequency downconverting means and transmitted through the second coaxial cable, into the high frequency output signal of the second wireless communication device, up-converting the frequency. High frequency signal transmission apparatus comprising a.