KR20110032229A - Duplexer and rf repeater including the same - Google Patents

Abstract

PURPOSE: A duplexer and an RF repeater including the same are provided to perform impedance matching between a transmitter filter and a receiver filter using a circulator. CONSTITUTION: Duplexers(420,440) comprises transmission filters(422,442), receiving filters(423,443), and circulators(421,441). The transmission filters filter the transmission signal in a first frequency band. The receiving filters filter the received signal in a second frequency band. The circulators are connected to the transmission filters, the receiving filters, and antennas(410,450). The circulators perform impedance matching.

Description

DUPLEXER AND RF REPEATER INCLUDING THE SAME}

The present invention relates to a duplexer using a circulator and an RF repeater including the same.

In general, a mobile communication system is composed of a base station, a base station controller, a mobile station (mobile terminal) and the like.

The base station and the mobile station communicate in a constant frequency band, and each base station has a constant call radius. Therefore, it is necessary to appropriately arrange a plurality of base stations so that the callable area of each base station overlaps each other, thereby making the callable area wider.

However, even if a large number of base stations are arranged to cover the entire city, call shadowing areas, which are still impossible to call, may occur in underground spaces of large buildings and inside of high-rise buildings. In order to solve the problem that the call shadow area occurs, a plurality of repeaters are separately installed in the shadow area to provide a smooth call service.

The repeater amplifies and transmits the base station signal to the radio wave shadow area so that the signal of the base station can reach the radio wave shadow area, and amplifies and filters the terminal signal so that the signal of the terminal located in the radio wave shadow area can reach the base station It solves the problem of radio wave shading by sending it out.

Meanwhile, the RF repeater according to the prior art transmits a TX (TX) signal from the base station to the terminal through one antenna, and also transmits a RX signal from the terminal to the base station and transmits the received / transmitted signal. The duplexer separates the filter using a transmission filter and a reception filter.

However, since the RF repeater according to the prior art matches the transmission filter and the reception filter of the duplexer through impedance matching, sufficient isolation is sufficient when the separation frequency between the transmission and reception signals is close to each other at 15 MHz or less. There is a problem that cannot be secured.

In addition, the RF repeater according to the prior art may cause damage due to oscillation when the isolation between the transmission and reception paths is not sufficiently secured.

An embodiment of the present invention provides a duplexer and an RF repeater including the duplexer which can facilitate impedance matching between two filters by matching a transmitting filter and a receiving filter through a circulator.

In addition, an embodiment of the present invention provides a duplexer and an RF repeater including the same to improve the call quality by improving the isolation of the transmitter / receiver by 20 ~ 30 dB using the inherent characteristics of the circulator.

In addition, an embodiment of the present invention provides a duplexer and an RF repeater including the same, which can greatly reduce the total loss and size of the repeater by adding a circulator to the duplexer.

As a technical means for achieving the above technical problem, a first aspect of the present invention is a transmission filter for filtering a transmission signal to a first frequency band, a reception filter for filtering a received signal to a second frequency band and the transmission A duplexer including a filter, a reception filter, and a circulator connected to an antenna to perform impedance matching is provided.

As a technical means for achieving the above technical problem, a second aspect of the present invention is a transmission filter for filtering a transmission signal to a first frequency band, a reception filter for filtering a received signal to a second frequency band and the transmission An RF repeater comprising a duplexer including a filter, a reception filter, and a circulator connected to an antenna to perform impedance matching.

As a technical means for achieving the above-described technical problem, a third aspect of the present invention is a circulator for impedance matching by connecting to the transmission filter, the reception filter and the transmission filter, the reception filter and the antenna, respectively. A first and a second duplexer comprising a forward RF module for amplifying and filtering the transmitted signal filtered by the first duplexer and transmitting the filtered signal to the second duplexer, and amplifying and filtering the received signal filtered by the second duplexer for the first and second duplexers It provides an RF repeater including a reverse RF module for transmitting to one duplexer.

According to one of the problem solving means of the present invention described above, by matching the transmission filter and the reception filter through the circulator can provide a duplexer and easy to match the impedance between the two filters and an RF repeater including the same.

According to another one of the problem solving means of the present invention described above, it is possible to provide a duplexer and an RF repeater including the same to improve the isolation of the transmitter / receiver by 20 ~ 30 dB using the inherent characteristics of the circulator.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "electrically connected" with another element in between. . In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

1 to 4, a duplexer and an RF repeater including the same according to an embodiment of the present invention will be described.

1 is a block diagram showing the internal configuration of a typical RF repeater.

Referring to FIG. 1, the RF repeater 200 includes a first antenna 210, a first duplexer 220, a forward RF module 230, a second duplexer 240, a second antenna 250, and a reverse RF module. 260.

Typically, the forward direction of mobile communication refers to the direction from the base station 100 to the terminal 300, and the backward direction refers to the direction from the terminal 300 to the base station 100. .

In the case of the forward channel, the transmission (TX) signal transmitted from the base station 100 to the RF repeater 200 is transmitted to the first duplexer 220 through the first antenna 210.

The first duplexer 220 includes a transmission filter 221 and a reception filter 222, and transmits a transmission (TX) signal transmitted through the first antenna 210 to the transmission filter 221, The transmission filter 221 filters the transmitted transmission (TX) signal to a fixed frequency band, extracts only the transmission (TX) signal, and transfers the signal to the forward RF module 230.

The forward RF module 230 removes noise from the transmission (TX) signal transmitted from the first duplexer 220, amplifies only the necessary signal, and delivers it to the second duplexer 240.

The forward RF module 230 includes a first low noise amplifier 231, a first band pass filter 232, and a first amplifier 233, wherein the first low noise amplifier 231 is delivered from the first duplexer 220. The low-noise amplified transmit (TX) signal and pass it to the first band pass filter 232, and the first band pass filter 232 once again filters the low-noise amplified transmit (TX) signal to transmit (TX) the signal After extracting only the transfer to the first amplifier 233, the first amplifier 233 amplifies the transmission (TX) signal to a specified signal level and delivers it to the second duplexer (240).

The second duplexer 240 includes a transmission filter 241 and a reception filter 242, and transmits a transmission (TX) signal transmitted through the first antenna 210 to the transmission filter 241, The transmission filter 241 extracts only the transmission (TX) signal by filtering the transmitted transmission (TX) signal to a predetermined frequency band and transmits the transmission TX signal to the second antenna 250 to be transmitted to the terminal 300.

In the reverse channel, a received (RX) signal transmitted from the terminal 300 to the RF repeater 200 is transmitted to the second duplexer 240 through the second antenna 250.

The second duplexer 240 transmits a reception (RX) signal transmitted through the second antenna 210 to the reception filter 242, and the reception filter 242 transmits the received reception (RX) signal to a predetermined frequency. After filtering by band, only the received (RX) signal is extracted and transmitted to the reverse RF module 260.

Reverse RF module 260 includes a second low noise amplifier 261, a second band pass filter 262, and a second amplifier 263, the second low noise amplifier 261 passing from the second duplexer 240. Amplify the received RX signal with low noise and pass it to the second band pass filter 262, and the second band pass filter 262 filters the low noise amplified RX signal once again to receive the RX signal. Only after extraction, the second amplifier 263 is transferred to the second amplifier 263, and the second amplifier 263 amplifies the received (RX) signal to a predetermined signal level and transmits the signal to the first duplexer 220.

The first duplexer 220 transmits a reception (RX) signal transmitted from the reverse RF module 260 to the reception filter 222, and the reception filter 222 transmits the received reception (RX) signal to a predetermined frequency band. After filtering, the RX signal is extracted and transmitted to the first antenna 210 to be transmitted to the base station 100.

2 is a block diagram showing an internal configuration of an RF repeater according to an embodiment of the present invention.

2, the RF repeater 400 according to an embodiment of the present invention may include a first antenna 410, a first duplexer 420, a forward RF module 430, a second duplexer 440, and a second An antenna 450 and a reverse RF module 460.

Here, the first duplexer 420 and the second duplexer 440 includes circulators 421 and 441, transmission filters 422 and 442, and reception filters 423 and 443, respectively.

3 is a view for explaining the operation of the circulator applied to an embodiment of the present invention.

As shown in FIG. 3, when power is input to any one of the three ports, the circulators 421 and 441 applied to the embodiment of the present invention transmit power to only one of the left and right ports. No power is delivered to the remaining ports.

That is, as shown in FIG. 3A, when power is input to port 1 of the circulator, power is transmitted to port 2 but no power is transmitted to port 3. In addition, as shown in (b) of FIG. 3, when power is input to port 2 of the circulator, power is transmitted to port 3 but power is not transmitted to port 1. Similarly, as shown in (c) of FIG. 3, when power is input to port 3 of the circulator, power is transmitted to port 1 but no power is transmitted to port 2.

2, in the case of the forward channel, the transmit (TX) signal transmitted from the base station 100 to the RF repeater 400 is transmitted to the first duplexer 420 through the first antenna 410.

The first duplexer 420 includes a circulator 421, a transmission filter 422, and a reception filter 423. Port 1 of the circulator 421 is connected to the first antenna 410. , Port 2 is connected to the transmission filter 422, and port 3 is connected to the reception filter 423.

Specifically, the circulator 421 receives a transmission (TX) signal from the first antenna 410 through port 1 and transmits it to the transmission filter 422 connected to the port 2, and the transmission filter 422 The filter extracts only the TX signal by filtering the TX signal transmitted from the circulator 421 to a predetermined frequency band and transmits the TX signal to the forward RF module 430. At this time, the transmission (TX) signal input through port 1 of the circulator 421 is not transmitted to the reception filter 423 connected to the port 3.

The forward RF module 430 includes a first low noise amplifier 431, a first band pass filter 432, and a first amplifier 433, and the first low noise amplifier 431 converts the transmit (TX) signal into low noise. The first band pass filter 432 amplifies and transfers the signal to the first band pass filter 432. The first band pass filter 432 filters the low noise amplified transmission (TX) again to extract only the transmission (TX) signal and then the first amplifier 433. The first amplifier 433 amplifies the transmit (TX) signal to a specified signal level and transmits the signal to the second duplexer 440.

The second duplexer 440 includes a circulator 441, a transmission filter 442, and a reception filter 443, and a port 1 of the circulator 441 is connected to the second antenna 450. Port 2 is connected to the receiving filter 443, and port 3 is connected to the transmitting filter 442.

Specifically, the transmission (TX) signal transmitted to the second duplexer 440 is input to the circulator 441 through the transmission filter 442, the circulator 441 is for transmission through the port 3 The TX signal is received from the filter 442 and transmitted to the second antenna 450 connected to the first port.

The second duplexer 440 according to the embodiment of the present invention as described above, a reception filter connected to the second port of the transmission (TX) signal input through the port 3 by the directionality of the circulator 441 Do not forward to (443). That is, in the second duplexer 440 according to an embodiment of the present invention, a transmission (TX) signal input to the transmission filter 442 receives a reception (RX) signal input from the second antenna 450. Since it is prevented from flowing into the receiving filter 443, there is an effect of improving the isolation between the transmission and reception signals by 20 to 30 dB.

In the reverse channel, a received (RX) signal transmitted from the terminal 300 to the RF repeater 400 is transmitted to the second duplexer 440 through the second antenna 450.

The circulator 441 of the second duplexer 440 receives the RX signal from the second antenna 450 through the port 1 and transmits the received RX signal to the receiving filter 443 connected to the second port. The filter 443 filters the received (RX) signal transmitted from the circulator 441 to a predetermined frequency band, extracts only the received (TX) signal, and delivers the received (TX) signal to the reverse module 460. At this time, the reception (RX) signal input through port 1 of the circulator 441 is not transmitted to the transmission filter 442 connected to the port 3.

The reverse RF module 460 includes a second low noise amplifier 461, a second band pass filter 462, and a second amplifier. The second low noise amplifier 461 amplifies the received (RX) signal with low noise to generate a first signal. The second band pass filter 462 transmits the second band pass filter 462 to the second amplifier 463 after extracting the received RX signal by filtering the low noise amplified RX signal once again. The second amplifier 463 amplifies the received (RX) signal to a designated signal level and delivers the signal to the first duplexer 420.

The first duplexer 420 transmits the RX signal transmitted from the second amplifier 463 to the first antenna 410 and transmits the received RX signal to the base station 100.

In detail, the reception (RX) signal transmitted to the first duplexer 420 is input to the circulator 421 through the reception filter 423, and the circulator 421 is a reception filter through port 3. The RX signal is received from the signal 423 and transmitted to the first antenna 410 connected to the first port. The first duplexer 420 according to an embodiment of the present invention as described above may include a circulator ( Due to the directionality of 421, a reception (RX) signal input through port 3 is not transmitted to the transmission filter 422 connected to port 2. That is, in the first duplexer 420 according to an embodiment of the present invention, a reception (RX) signal input to the reception filter 423 is transmitted with a transmission (TX) signal input from the first antenna 410. Since it is prevented from flowing into the transmission filter 422, there is an effect of improving the isolation between the transmission and reception signals by 20 to 30 dB.

4 is an example of a duplexer according to an embodiment of the present invention.

As shown in FIG. 4, the duplexer 420 according to an embodiment of the present invention combines a plurality of coaxial ceramic resonators to respectively receive a filter 423 and a filter 422 for transmission. In this configuration, the circulator 421 is inserted in the middle to perform impedance matching. The receiving filter 423 and the transmitting filter 422 include a plurality of coaxial ceramic resonators connected in parallel. Here, impedance matching means that the receiving filter 423 and the transmitting filter 422 appear to have infinite impedance to each other, but both are matched to 50 Ω by the antenna port.

A typical duplexer includes a waveguide type filter. The use of the waveguide type filter has a good characteristic in terms of isolation, but the size of the duplexer is large, resulting in a large duplexer. In contrast, the present invention includes a filter and a circulator corresponding to about 10% of the size of the waveguide type filter, thereby making it possible to construct an improved duplexer in isolation and size.

Since the duplexer 420 according to the embodiment of the present invention as described above uses the circulator 421 to perform impedance matching between the transmission filter 422 and the reception filter 423, There is an effect that can greatly reduce the size and insertion loss (Insertion Loss).

In addition, the duplexer 420 according to an embodiment of the present invention as described above is used in a small RF repeater because of its small size, in particular, even when the separation frequency between the transmission and reception signals is close to each other at 15 MHz or less. It is effective to ensure sufficient isolation of 30 dB.

One embodiment of the present invention can also be implemented in the form of a recording medium containing instructions executable by a computer, such as a program module executed by the computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, computer readable media may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transmission mechanism, and includes any information delivery media.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

1 is a block diagram showing the internal configuration of a typical RF repeater.

2 is a block diagram showing an internal configuration of an RF repeater according to an embodiment of the present invention.

3 is a view for explaining the operation of the circulator applied to an embodiment of the present invention.

4 is an example of a duplexer according to an embodiment of the present invention.

Claims (7)

A transmission filter for filtering the transmission signal to the first frequency band, A reception filter for filtering the received signal into a second frequency band; A circulator connected to the transmission filter, the reception filter, and an antenna to perform impedance matching Duplexer comprising a. The method of claim 1, The transmission filter and the reception filter each include a plurality of coaxial ceramic resonators connected in parallel. An RF repeater comprising the duplexer according to claim 1. The method of claim 3, wherein The RF repeater, A low noise amplifier for low noise amplifying the filtered transmission signal through the duplexer, A band pass filter for filtering a low noise amplified transmission signal through the low noise amplifier; An amplifier for amplifying the transmitted signal filtered through the band pass filter RF repeater that further comprises. First and second duplexers each including a transmission filter, a reception filter, and a circulator configured to perform impedance matching by connecting to the transmission filter, the reception filter, and an antenna; A forward RF module for amplifying and filtering the transmitted signal filtered by the first duplexer and transmitting the filtered signal to the second duplexer; A reverse RF module for amplifying and filtering the received signal filtered by the second duplexer and transmitting the filtered signal to the first duplexer RF repeater comprising a. The method of claim 5, A circulator of the first duplexer is connected with a first antenna in communication with a base station, The circulator of the second duplexer is connected to a second antenna in communication with the terminal. The method of claim 5, And the transmitting filter and the receiving filter each include a plurality of coaxial ceramic resonators connected in parallel.

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