WO2008117972A1

WO2008117972A1 - M/w repeater using complex frequency band

Info

Publication number: WO2008117972A1
Application number: PCT/KR2008/001653
Authority: WO
Inventors: Tae-Hoan Park; Seung-Han Lee
Original assignee: Hutech21 Co., Ltd.
Priority date: 2007-03-23
Filing date: 2008-03-24
Publication date: 2008-10-02
Also published as: KR20080086777A; KR100876996B1

Abstract

A microwave repeater system for multi-band signals is disclosed. A microwave repeater system for multi-band signals includes a donor system having a donor RF unit and a donor M/W unit and a remote system having a remote M/W unit and a remote RF unit to convert a communication signal between a base station and a mobile station to an IF or RF signal and an M/W signal. Each unit has a filter filtering a communication signal, an amplifier amplifying a signal up to a specific level, a multiplexer, and an MCU controlling the filter, the amplifier, and the multiplexer. The microwave repeater system includes a VCTCXO mounted to the remote M/W unit and controlled by a voltage, an FA DET circuit module mounted to the donor RF unit, converters mounted to the donor RF unit and the remote RF unit respectively, and feed forward circuit modules mounted to the donor M/W unit and the remote M/W unit respectively.

Description

M/W REPEATER USING COMPLEX FREQUENCY BAND

Technical Field

The present invention relates to a microwave repeater system for multi-band signals, and more particularly to a microwave repeater system for multi-band signals that enables prompt synchronization without any time delay, selection and transfer of only an actually serviced signal, and enhancement of amplification efficiency due to compensation for distortion of a signal.

Background Art

In general, repeater signals include CDMA signals, WCDMA signals, and WiBro signals. CDMA and WCDMA are representative signal transmission methods for 2G and 3G mobile communications respectively, and a WiBro system for communication using WiBro signals refers to a wireless mobile internet that enables a user to use a high speed internet service while the user is moving, and to a 2.3 GHz wireless internet service enabling a user to freely use the Internet even in a moving vehicle or subway train like a mobile phone by installing a WiBro mobile station. Fig. 1 is a block diagram schematically illustrating a donor radio frequency (RF) unit and a donor microwave (M/W) unit of a conventional microwave repeater system.

Fig. 2 is a block diagram schematically illustrating a remote M/W unit and a remote RF unit of the conventional repeater system.

Referring to Figs . 1 and 2 , the conventional repeater system includes an antenna receiving a signal, a donor system having a donor RF unit 10 and a donor M/W unit 20 selecting and transmitting the received signal, and a remote system having a remote M/W unit 30 and a remote RF unit 40.

The donor RF unit 10 receives a forward signal from a base station through a wire or RF cable via an input port. The forward signal is filtered by an input filter 10-5 and is amplified up to a specific level by a pre-amplifier 11. The forward signal is converted to a specific signal by a converter 13 , and a modem signal and a pilot signal of a modem signal unit 165-1 and a pilot signal unit 16 that are carried in the forward signal are transferred to a post-amplifier 13-5 to be amplified, pass through a multiplexer 14, and are transmitted to the donor M/W unit 20 through a concentric cable via a bias tee 15-5.

In the donor M/W unit 20, the forward signal input from the donor RF unit 10 is input to a multiplexer 22 so that the modem signal and the pilot signal are separated through a bias tee 20-5, and the separated modem signal is transmitted to a modem and the separated pilot signal is supplied to a phase locked loop (PLL) . The service signal other than the pilot signal and the modem signal passes through a pre-amplifier 22-5 and a filter 23 and is mixed with a PLL signal. The service signal passes through a filter 23-5 and a post-amplifier 24, is filtered by an output filter 24-5, and is wirelessly transmitted to an antenna of the remote M/W unit 30 through an M/W antenna.

In the remote M/W unit 30, the forward signal wirelessly received from the donor M/W unit 20 is received by an M/W antenna, passes through a filter 30-5, and is amplified by a pre-amplifier 31. The amplified forward signal passes through a filter 31-5, is mixed with a reference frequency signal of a PLL, and is converted to an IF or RF frequency signal that is to be transmitted to the remote RF unit 40. Then, the forward signal passes a filter 32 to be filtered and is amplified by a post-amplifier 32-5. The amplified forward signal passes through a multiplexer 33 and is transmitted to the remote RF unit 40 through an RF concentric cable.

In the remote RF unit 40, the forward signal received from the remote M/W unit 30, i.e. the IF or RF signal passes through a bias tee 40-5, is separated into a specific signal through a multiplexer 41, passes through a pre-amplifier 42 to be input to a converter 43 , and restores a service band of a frequency of the discriminated frequency assignment (FA) . Then, after the multiplexer 41 separates a synchronization signal, i.e. a pilot signal from the IF or RF signal to create a 10 MHz reference clock, it supplies the reference clock to the remote M/W unit 30 via a bias tee 40-5. Then, an oven-controlled crystal oscillator (OCXO) 45 extracts a synchronization signal and supplies the synchronization signal to the converter 43. Then, the forward signal passes through a post-amplifier 43-5 and is filtered by a filter 44, and then is transmitted to a personal terminal .

However, the donor system having the donor RF unit and the donor M/W unit and the remote system having the remote M/W unit and the remote RF unit cannot transmit a 2G signal, a 3G signal, and a WiBro signal at the same time. Accordingly, there exist demands on repeater systems each satisfying various communication signals such as a 2G signal, a 3G signal, and a WiBro signal. Moreover, the repeater systems do not use a method for selection and transfer of only an actually serviced signal, making it impossible to use a wide signal bandwidth and increase transmission speed.

Further, a synchronization signal cannot be promptly extracted due to initial stabilization time of an OCXO, causing delay in synchronization of communication signals of the units of the microwave repeater system.

Furthermore, amplification of a post-amplifier essentially provided in the microwave repeater system for improvement of transmission gain of communication signals deteriorates .

Therefore, there has been a demand on a system for synchronization of communication signals and improvement of transmission gain of communication signals that enables transmission of various communication signals such as a 2G signal, a 3G signal, and a WiBro signal by selection of only an actual service signal for use of a wide service signal bandwidth.

Technical Problem

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a microwave repeater system for multi- band signals that enables shortening of synchronization time of its units by using a synchronizing unit controlled by a voltage.

It is another object of the present invention to provide a microwave repeater system for multi-band signals that enables use of a wide signal bandwidth and enhancement of transmission rate, by using a signal detecting technology and a variable converter technology for selecting and transferring only an actually serviced signal, in order to transmit multi- band signals such as a 2G signal, a 3G signal, and a WiBro signal.

It is still another object of the present invention to provide a microwave repeater system for multi-band signals that includes a circuit module for enhancing transmission gain by compensating for distortion of a signal.

Technical Solution

In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a microwave repeater system for multi-band signals that comprises a donor system having a donor RF unit and a donor M/W unit and a remote system having a remote M/W unit and a remote RF unit to convert a communication signal between a base station and a mobile station to an IF or RF signal and an M/W signal, each unit having a filter filtering a communication signal, an amplifier amplifying a signal up to a specific level, a multiplexer, and an MCU controlling the filter, the amplifier, and the multiplexer, the microwave repeater system comprising: a VCTCXO mounted to the remote M/W unit and controlled by a voltage to extract a synchronization signal and synchronize the units; an FA DET circuit module mounted to the donor RF unit to select only an FA contained in a communication signal under the control of the MCU; converters mounted to the donor RF unit and the remote RF unit respectively to extract only an actually serviced signal from frequency signals of an FA whose section is discriminated by the MCU; and feed forward circuit modules mounted to the donor M/W unit and the remote M/W unit respectively to synthesize noise in a communication signal by reversing the phase thereof and offset the noise.

Advantageous Effects

Accordingly, a microwave repeater system for multi-band signals according to the present invention can be controlled to leave only an actually serviced frequency band signal by removing an area where there is no service signal through an FA DET circuit and a converter in a donor RF unit. Further, the micro repeater system for multi-band signals enables enhancement of amplification efficiency by using a feed forward circuit without mounting a high-priced amplifier, in order to increase the efficiency of a final amplifying port in a donor M/W unit and a remote M/W unit. Furthermore, the micro repeater system for multi-band signals enables extraction of a synchronization signal using a voltage-controlled, temperature compensated crystal oscillator

(VCTCXO) in a relatively short time period by a remote M/W unit.

Description of Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a block diagram schematically illustrating a donor RF unit and a donor M/W unit of a conventional microwave repeater system; Fig. 2 is a block diagram schematically illustrating a remote M/W unit and a remote RF unit of the conventional microwave repeater system;

Fig. 3 is a block diagram schematically illustrating a donor RF unit and a donor M/W unit of a microwave repeater system for multi-band signals according to an embodiment of the present invention;

Fig. 4 is a block diagram schematically illustrating a remote M/W unit and a remote RF unit of the microwave repeater system for multi-band signals according to the embodiment of the present invention;

Fig. 5 is a block diagram schematically illustrating an FA DET circuit module of the donor RF unit according to the embodiment of the present invention;

Fig. 6 is a block diagram schematically illustrating one of converters of the donor RF unit and the remote RF unit according to the embodiment of the present invention;

Fig. 7 is a view illustrating selection and transmission of only a corresponding service frequency band signal by the donor RF unit according to the embodiment of the present invention;

Fig. 8 is a view illustrating restoration of a transmitted service frequency band signal by the remote RF unit according to the embodiment of the present invention;

Fig. 9 is a block diagram schematically illustrating one of feed forward circuit modules of the donor M/W unit and the remote M/W unit according to the embodiment of the present invention; and Fig. 10 is a view illustrating setting of a bandwidth by selecting one of serviced bands of 40 MHz, 20 MHz, 10 MHz, or 5 MHz according to the embodiment of the present invention. Best Mode

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

Fig. 3 is a block diagram schematically illustrating a donor RF unit and a donor M/W unit of a microwave repeater system for multi-band signals according to an embodiment of the present invention. Fig. 4 is a block diagram schematically illustrating a remote M/W unit and a remote RF unit of the microwave repeater system for multi-band signals according to the embodiment of the present invention.

As depicted in Figs . 3 and 4 , the microwave repeater system for multi-band signals according to the embodiment of the present invention includes a donor system 100 and 200 receiving a frequency signal of a base station and converting the frequency signal to an M/W signal and a remote system 300 and 400 converting the M/W signal output from the donor system 100 and 200 into a specific frequency.

The microwave repeater system according to the embodiment of the present invention is one used for a wireless network related to mobile communication such as code division multiple access (CDMA) for 2G, wideband code division multiple access (WCDMA) for 3G, a trunked radio system (TRS) , and a global system for mobile communications (GSM) , a digital TV, a digital multimedia broadcasting (DMB) system, a wireless internet such as a wireless broadband internet (WiBro) and the worldwide interoperability for microwave access (WiMax) , an internet protocol TV (IPTV) , and a broadband convergence network (BcN) , in order to secure a service for subscriber terminals located in a shadow area other than a base station service coverage area. In particular, the microwave repeater system according to the embodiment of the present invention will be described, considering only a 2G signal, a 3G signal, and a WiBro signal, but is not limited thereto.

Hereinafter, in the descriptions of elements of the microwave repeater system, it is assumed that a direction in which a signal is transferred from the donor RF unit 100 to the donor M/W unit 200 and from the remote M/W unit 300 to the remote RF unit 400 is the direction of a forward signal. On the other hand, a backward signal may be transferred from the donor M/W unit 200 to the donor RF unit 100, and the detailed description thereof will be omitted.

Hereinafter, operations of elements of the units 100, 200, 300, and 400 will be described in detail with reference to Figs . 3 and 4.

The donor RF unit 100 receives a forward signal from a base station through a wire or an RF cable via an input port . The forward signal is filtered by an input filter 105 and is amplified up to a specific level by a pre-amplifier 110, and a frequency assignment (FA) corresponding to the level is selected by an FA DET circuit module 120. The FA DET circuit module 120 uses a signal detecting technology by which only an actually serviced signal is selected and transferred, and information about an extracted FA location signal is transferred to an MCU 480 of the remote RF unit 400, which will be described in detail with reference to Fig. 5. The forward signal passes through a converter 130, and only a service frequency band of a discriminated FA is left and an area where there exists no signal is removed when the forward signal passes. The converter 130 will be described in detail with reference to Fig. 6. A modem signal of a modem signal unit 165 and a pilot signal of a pilot signal unit 160 are carried in the forward signal and are transferred to a post- amplifier 135. An oven controlled crystal oscillator (OCXO) 170 extracts a synchronization signal and supplies it to the converter 130. Then, the forward signal is amplified by the post-amplifier 135, passes a multiplexer 140, and is transmitted to the donor M/W unit 200 through a concentric cable via a bias tee 155.

In the donor M/W unit 200, the forward signal transferred from the donor RF unit 100 is input to a multiplexer 22 through a bias tee 205 and is branched to a modem signal and a pilot signal, and the modem signal is transmitted to a modem signal unit 221 and the pilot signal is supplied to a PLL 222. The service signal other than the pilot signal and the modem signal pass through a pre-amplifier 225 and a filter 230, is mixed with a signal of the PLL 222 that received a 10 MHz reference frequency of a 10 MHz unit 223 by a mixer 231, passes through a filter 235 and a post- amplifier 240, is filtered by an output filter 245, and is wirelessly transmitted to an antenna of the remote M/W unit 300 through an M/W antenna. The post-amplifier will be described in detail with reference to Fig. 6.

In the remote M/W unit 300, the forward signal wirelessly received from the donor M/W unit 200 is received by an M/W antenna, passes through an input filter 305, and is amplified by a pre-amplifier 310. The amplified forward signal passes through a filter 315 and is mixed with a signal of a PLL 316 that received a 10 MHz reference frequency of a 10 MHz unit 330 to be converted to an IF or an RF signal. The forward signal passes through a filter 320 to be filtered and is amplified by a post-amplifier 325. The amplified forward signal passes through a multiplexer 330 and is transmitted to the remote RF unit 400 through an RF concentric cable via a bias tee 340.

In the remote RF unit 400, the forward signal received from the remote M/W unit 300, i.e. an IF or RF signal passes through a bias tee 405 and is branched to a specific signal by a multiplexer 410. The multiplexer 410 branches a synchronization signal, i.e. a pilot signal from the IF or RF signal to generate a 10 MHz reference clock, which passes through a bias tee 405 to be supplied to the remote M/W unit 300. The pilot signal passes through a pre-amplifier 420 to be input to a converter 430, and leaves only a service signal band of the FA frequency discriminated by the converter 130 of the donor RF unit 100 and removes a section where there exists no signal to restore the service band of the FA frequency to the original forward signal. The converter 430 is operated in the order opposite to the operation order of the converter 130 of the donor RF unit 100 to restore the forward signal, and information about the FA location signal extracted by the FA DET circuit module 120 is received by an MCU 480. A VCTCXO is controlled by a voltage and may extract a synchronization signal more promptly than a conventional OCXO controlled using heat due to its shorter initial stabilization time than that of the OCXO. Although not illustrated, global positioning system (GPS) modules are installed in the donor RF unit 100 and the remote RF unit 400 respectively to use their signals as a synchronization signal for a service signal. The forward signal passes through a post-amplifier 435, is filtered by an output filter 440, and is transmitted to a personal terminal (not shown) . The VCTCXO 450 is used for synchronization of the units of the microwave repeater system according to the embodiment of the present invention, and promptly synchronizes the units when only a service signal is selected and transferred in association with a FA DET circuit module and a converter of Fig. 3

Fig. 5 is a block diagram schematically illustrating an FA DET circuit module of the donor RF unit according to the embodiment of the present invention.

Fig. 6 is a block diagram schematically illustrating one of converters of the donor RF unit and the remote RF unit according to the embodiment of the present invention.

Fig. 7 is a view illustrating selection and transmission of only a corresponding service frequency band signal by the donor RF unit according to the embodiment of the present invention.

Fig. 8 is a view illustrating restoration of a transmitted service frequency band signal by the remote RF unit according to the embodiment of the present invention.

As illustrated in Fig. 5, the FA DET circuit module 120 includes a PLL 121 generating a variable frequency, a saw filter 123 filtering the FA signal, a mixer 124 mixing the variable frequency with the FA signal, and an FA DET circuit 122 detecting the FA of the signal. More particularly, the MCU 180 sweep-checks a frequency level of a central section of an FA signal 600 input through the amplifier 110 using the variable PLL 121 and the FA DET circuit 125, and determines existence of the FA signal.

As illustrated in Fig. 6, the converter 130 of the donor RF unit 100 includes a first variable PLL 131 mixing FA signals and converting the frequencies of the FA signals down to an IF frequency, a filter 132 leaving only a service bandwidth of an FA signal frequency converted down to an IF frequency and filtering and removing a section where there is no signal, and a second variable PLL 133 varying and fixing the phase of the removed signal . Accordingly, it is possible to select only an actually serviced frequency bandwidth 610 from a bandwidth received by a base station using the variable PLL 131. It is also possible not only to select a specific frequency bandwidth using a general PLL but also to easily select only an actually serviced frequency bandwidth using the variable PLLs 131 and 133.

Accordingly, the MCU 180 controls only the service frequency bandwidth to pass through the FA DET circuit module 120 and the converter 130. The MCU 180 of the donor RF unit 100 transfers information about an FA location signal extracted by the FA DET circuit module 120 and the converter 130 to the MCU 480 of the remote RF unit 100. As illustrated in Fig. 7, the MCU 180 of the donor RF unit 100 removes a section where there is no signal from a frequency bandwidth 600 of a signal received from a base station and leaves only a signal 610 of an actually serviced frequency band, using the FA DET circuit module 120 and the converter 130.

As illustrated in Fig. 8, the remote RF unit 400 may restore a signal of an actually serviced frequency bandwidth 620 that has been transferred from the donor RF unit 100 to an original base station signal using the MCU 480 and the converter 430.

Accordingly, when the FA DET circuit module and the converter are associated with each other to select and transfer only an actually serviced signal, the VCTCX may promptly synchronize the units. Furthermore, the feed forward circuit module enables easy transmission of service signals by the units of the microwave repeater system according to the embodiment of the present invention by amplifying signals of the paths by the VCTCXO without any delay.

Fig. 9 is a block diagram schematically illustrating one of feed forward circuit modules of the donor M/W unit and the remote M/W unit according to the embodiment of the present invention.

As illustrated in Fig. 9, the feed forward circuit modules 240' of the donor M/W unit and the remote M/W unit reverse the phase of noises (or distorted components) of the amplifiers in more than two paths at final output ports and offset the noises to amplify and output only actual signals.

The feed forward circuit module 240' includes a first path 241 adjusting the phase and level of an input signal and amplifying the input signal and is divided into a second delay part and a second hybrid part damping the input signal, a second path 242 delaying the input signal, adjusting the phase and level of the input signal, and transferring a harmonic wave to a first hybrid part, and a third path 245 receiving the signal damped by the second hybrid part and the signal of the first hybrid part, reversing the phases of the signal damped by the second hybrid part and the signal of the first hybrid part, and removing the harmonic wave. The first path 241 has a level part 241-1 and a phase part 241-2 removing the harmonic wave, an amplifier 241-3 amplifying the input signal, a second coupler 241-4 branching the input signal to the second delay part and the second hybrid part, and a second delay part 241-5 coinciding the signal of the second path 242 with a delay.

The second path 242 has a first coupler 242-1 that branches the input signal to the first path 241 and the second path 242, a second delay part 242-2 reversing the phase of the signal from which the harmonic wave is removed, and a level part 242-3 and a phase part 242-4 removing the harmonic wave.

The third path 245 has a third delay part 245-1 performing a mapping under the control of an MCU so that a service frequency band switch is identical with the second delay part, a level part 245-2 and a phase part 245-3 removing the harmonic wave, and an amplifier 245-4 amplifying a signal.

More particularly, an input signal is branched into two signals for the first path 241 and the second path 242 by the first coupler 242-1. The first path 241 removes a harmonic wave using the level part 241-1 and the phase part 242-2, amplifies a signal using the amplifier 241-3, and branches an inter modulation (IM) component of the signal that contains a harmonic wave to two signals again using the second coupler 241-4. One of them is input to the second delay part 241-5 and the other one passes through the second hybrid part 243, is damped at a specific rate, and merges into an output of the second path 242 through the first hybrid part 244. The second path 242 removes a harmonic wave component of an input signal by adjusting the level part 242-4 and the phase part 242-4 and the second delay part 242-2 removes an input signal component and leaves only an IM component by switching a delay of a corresponding frequency band through the MCU and reversing the phase of the signal of the first path 241 and transfers the IM component to the third path 245.

The third delay part 245-1 of the third path 245 coincides a phase of a signal with that of a signal coupled through the first hybrid part 244 by mapping switching of selection of a corresponding frequency band by an MCU as in the second delay part 242-2. The phase and level of a signal is adjusted such that only a harmonic wave component is detected by the third amplifier 245-2 and the third PM 245-3 of the third path 245.

After the third path 245 generates a harmonic wave signal, it removes a harmonic wave component by reversing the phase of the harmonic wave signal, merging a signal of the first path 241 into the third hybrid part 246, and detecting only an actual signal. Referring to Figs. 3 and 4, the feed forward circuit modules 240' and 325 may be preferably provided in the post-amplifier 240 of the donor M/W unit 200 and the post-amplifier 325 of the remote M/W unit 300.

Accordingly, the amplification efficiency of the microwave repeater system according to the embodiment of the present invention may be enhanced by using the feed forward circuit modules 240' and 325 amplifying signals, so that an IM component is easily removed by adding at least two paths and a plurality of delay parts to conventional feed forward circuit modules without mounting high-priced amplifiers for increasing a final amplifying terminal.

When only an actually serviced signal is selected and transferred in association with an FA DET circuit module and a converter, the VCTCXO 450 may promptly synchronize the units. The feed forward circuit module 240' may enable the units of the microwave repeater system according to the embodiment of the present invention to easily transmit service signals due to normal operations of modules of the remote units by prompt synchronization of the VCTCXO 450 and the service signals may be promptly transmitted to the units by selecting service bands of at least two sections at the same time.

Fig. 10 is a view illustrating setting of a bandwidth by selecting one of serviced bands of 40 MHz, 20 MHz, 10 MHz, or 5 MHz according to the embodiment of the present invention.

The MCU 280 of the donor M/W unit 200 may calculate the frequency band of the FA of a generated forward signal, i.e. an M/W signal in advance and transmit and receive a signal with the remote M/W unit 300 by selectively setting a band of the signal. For example, the MCU 280 of the donor M/W unit 200 mixes a signal amplified by an amplifier with a local frequency set in a variable PLL signal in a mixer and is programmed to set a frequency band by selecting at least one actually serviced band from 40 MHz (first section) , 20 MHz (second section) 10 MHz (third section) , and 5 MHz (fourth section) . That is, although conventionally only one frequency band is necessary to service one signal, the MCU 280 of the donor M/W unit 200 may select at least one frequency band from the FA bands of a 2G signal, a 3G signal, and a WiBro signal by using the above-mentioned four selectable bands to transmit and receive signals.

Therefore, according to the embodiment of the present invention, amplification of a feed forward circuit module can be achieved without any delay due to prompt synchronization of the VCTCXO. Furthermore, the units of the microwave repeater system can easily transmit service signals mutually, by selecting and transferring signals of at least two actually used frequency bands by an FA DET circuit module and converters .

Although the preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

Claim 1. A microwave repeater system for multi-band signals that comprises a donor system having a donor RF unit and a donor M/W unit and a remote system having a remote M/W unit and a remote RF unit to convert a communication signal between a base station and a mobile station to an IF or RF signal and an M/W signal, each unit having a filter filtering a communication signal, an amplifier amplifying a signal up to a specific level, a multiplexer, and an MCU controlling the filter, the amplifier, and the multiplexer, the microwave repeater system comprising: a VCTCXO mounted to the remote M/W unit and controlled by a voltage to extract a synchronization signal and synchronize the units; an FA DET circuit module mounted to the donor RF unit to select only an FA contained in a communication signal under the control of the MCU; converters mounted to the donor RF unit and the remote RF unit respectively to extract only an actually serviced signal from frequency signals of an FA whose section is discriminated by the MCU; and feed forward circuit modules mounted to the donor M/W unit and the remote M/W unit respectively to synthesize noise in a communication signal by reversing the phase thereof and offset the noise.

Claim 2. The microwave repeater system as set forth in claim 1, wherein the FA DET circuit module comprises a PLL generating a variable frequency signal, a filter filtering an FA signal, a mixer mixing the variable frequency signal with the FA signal, and an FA DET circuit detecting the FA of the FA signal .

Claim 3. The microwave repeater system as set forth in claim 1 or 2, wherein the FA DET circuit module detects a 2G signal, a 3G signal, and a WiBro signal.

Claim 4. The microwave repeater system as set forth in claim 1, wherein each converter comprises: a first variable PLL converting an FA signal down to an IF frequency; a filter filtering the converted FA signal by removing a section where there is no signal and leaving only a service bandwidth of the FA signal; and a second variable PLL varying and fixing a phase of the filtered signal .

Claim 5. The microwave repeater system as set forth in claim 1, wherein the feed forward circuit module comprises: a first path adjusting the phase and level of an input signal and amplifying the input signal and divided into a second delay part and a second hybrid part damping the input signal; a second path delaying the input signal, adjusting the phase and level of the input signal, and transferring a harmonic wave to a first hybrid part; and a third path receiving the signal damped by the second hybrid part and the signal of the first hybrid part, reversing the phases of the signal damped by the second hybrid part and the signal of the first hybrid part, and removing the harmonic wave, wherein the first path has a level part and a phase part removing the harmonic wave, an amplifier amplifying the input signal, a second coupler branching the input signal to the second delay part and the second hybrid part, and a second delay part coinciding the signal of the second path with a delay, the second path has a first coupler branching the input signal to the first path and the second path, a second delay part reversing the phase of the signal from which the harmonic wave is removed, and a level part and a phase part removing the harmonic wave, and the third path has a third delay part performing a mapping under the control of an MCU so that a service frequency band switch is identical with the second delay part, a level part and a phase part removing the harmonic wave, and an amplifier amplifying a signal.

Claim 6. The microwave repeater system as set forth in claim 1, wherein in the case of a forward signal, the MCU of the donor M/W unit is programmed to set a transmission/reception band by selecting at least one of bands of the FA of a generated M/W signal that include 40 MHz, 20

MHz, 10 MHz, and 5 MHz to transmit and receive the forward signal to and from the remote M/W unit.