KR100329262B1 - A cancellation circuit of inter-modulation product by RF passive component in repeater - Google Patents

Abstract

The disclosed elimination circuit actively removes the distortion signal according to the level of the generated distortion signal, detects the generated distortion signal, adjusts the attenuation amount and the phase shift angle according to the detected distortion signal, and is output to the output line of the received signal. It is to remove the distortion signal.

A duplexer for processing a transmission signal and transmitting the same through an antenna, and processing and outputting a reception signal received through the antenna; A distortion signal detector for detecting a distortion signal using a transmission signal input to the duplexer and a signal output from the duplexer to the antenna; And a distortion signal removing unit that removes the distortion signal included in the received signal output by the duplexer as the distortion signal detected by the distortion signal detection unit, and further includes a distortion signal removal amount control unit for detecting and detecting the generation amount of the distortion signal. According to the amount of generation of the distortion signal, the distortion signal removing unit and the distortion signal detecting unit attenuate the phase shift angle by adjusting the amount of attenuation and the active signal is actively operated to remove completely.

Description

A cancellation circuit of inter-modulation product by RF passive component in repeater

The present invention provides a circuit for removing high frequency passive element intermodulation distortion signals in a repeater which effectively removes a distortion signal generated by a duplexer, which is a high frequency passive element, and outputted to an output line of a received signal. It is about.

Due to the development of information and communication technology, change of life style and economic growth, the form of communication culture is changing rapidly, and in the era of information, the demand for high-speed information delivery is regardless of time and place. Mobile communication systems that can receive communication services in marine and mountainous areas, etc. are becoming an important communication medium indispensable in daily life.

The mobile communication system divides an entire service area into a small service area called a cell, unlike a wide area method using a service area as one wide area, and allocates a certain number of radio channels available within each cell. Will be allocated.

And the wireless base station (Cell Site) installed in each cell is controlled centrally in the switching system, the repeater is a low output RF signal transmitted from the wireless base station and the mobile communication terminal for smooth communication between the wireless base station and the user's mobile communication terminal It receives and, amplifies the received RF signal and serves to relay to the mobile terminal and the wireless base station.

The repeater uses a duplexer that is a passive element to relay wireless communication. That is, the duplexer processes the transmission signal and transmits it through the antenna, and processes and outputs the reception signal received through the antenna.

When the duplexer processes a transmission signal and transmits it through an antenna, a cross-modulated distortion signal is generated, and the generated distortion signal is output to a line for outputting a received signal, thereby reducing the relay capability of the repeater, and relaying a wireless communication signal. Is distorted and degrades call quality. Therefore, it is necessary to remove the intermodulated distortion signal generated while the duplexer of the repeater processes the transmission signal.

In order to remove the distortion signal generated in the duplexer, a passive method of improving isolation for each path has been conventionally used by increasing the number of resonators to increase the number of poles of the band pass filter. However, the method of increasing the order of the band pass filter does not actively cope with external environmental changes, and thus there is a problem that the scope of application is limited.

Accordingly, an object of the present invention is to provide a circuit for removing high frequency passive element intermodulation distortion signals in a repeater which actively removes distortion signals in accordance with the level of the distortion signals generated.

Another object of the present invention is to detect the distortion signal generated, and to automatically control the attenuation amount of the attenuator and the phase shift angle of the phase shifter according to the detected distortion signal to remove the distortion signal output to the output line of the received signal The present invention provides a circuit for canceling a high frequency passive element intermodulation distortion signal in a repeater.

According to the circuit for removing the high frequency passive element intermodulation distortion signal in the repeater of the present invention for achieving the above object, a duplexer for processing and transmitting the transmission signal through the antenna and processing the output signal received through the antenna; A distortion signal detector for detecting a distortion signal using a transmission signal input to the duplexer and a signal output from the duplexer to the antenna; And a distortion signal removing unit configured to remove the distortion signal included in the received signal output by the duplexer as the distortion signal detected by the distortion signal detector.

The distortion signal detector may include: a first coupler configured to attenuate and transmit a predetermined level of the transmission signal; A first attenuator for attenuating the attenuated output signal of the first coupler; A first phase shifter for inverting the phase of the output signal of the attenuator; A second coupler configured to attenuate and output a signal output from the duplexer to the antenna by a predetermined level; And a first adder configured to detect the distortion signal by adding the output signal of the phase converter to the attenuated output signal of the second coupler, wherein the distortion signal removing unit is configured to attenuate the distortion signal output from the distortion signal detector. 2 attenuators; A second phase shifter for inverting the phase of the output signal of the attenuator; An amplifier for amplifying the output signal of the phase converter; And a second adder configured to remove the distortion signal by adding the output signal of the amplifier and the received signal output by the duplexer.

And a distortion signal removal amount control means for detecting a generation amount of the distortion signal and adjusting attenuation amount and phase shift angle of the distortion signal removal unit and the distortion signal detection unit according to the generation amount of the distortion signal detected. A third coupler configured to attenuate and output a signal output from the duplexer to the antenna by a predetermined level; A fourth coupler configured to attenuate and output a distortion signal outputted from the distortion signal detector by a predetermined level; A multiplexer for selectively passing the output signals of the third and fourth couplers; A PLL circuit for generating a signal of a predetermined frequency; A mixer for mixing output signals of the multiplexer and the PLL circuit to generate a signal having a desired frequency; A band pass filter for detecting a desired frequency signal from the output signal of the mixer; A power detector detecting power of a signal output from the band pass filter; And controlling the selection operation of the multiplexer, controlling the frequency of the signal generated by the PLL circuit, and determining the power of the transmission signal and the distortion signal using the output signal of the power detector, thereby removing the distortion signal removal unit and the distortion signal detection unit. It is characterized by consisting of a controller for controlling the amount of attenuation and the phase shift angle.

1 is a circuit diagram showing an embodiment according to the removal circuit of the present invention,

2 is a view for explaining the operation of the coupler used in the removal circuit of the present invention,

Figure 3 is a circuit diagram showing another embodiment according to the removal circuit of the present invention.

* Description of the symbols for the main parts of the drawings *

100: duplexer 110: distortion signal detector

111, 117, 201, and 203: first to fourth couplers

113, 121: first and second attenuators 115, 123: first and second phase shifters

119, 127: first and second adders 120: distortion signal removing unit

125, 130, 140: amplifier 200: distortion signal removal amount control means

205: multiplexer 207: PLL circuit

209 Mixer 211 Bandpass Filter

213: power detector 215: controller

ANT: Antenna TX: Transmission Signal

RX: Received Signal

Hereinafter, a circuit for removing high frequency passive element intermodulation distortion signals in a repeater of the present invention will be described in detail with reference to the accompanying drawings.

1 is a circuit diagram illustrating an embodiment of a removal circuit of the present invention. As shown therein, the duplexer 100 processes the transmission signal TX and transmits it through the antenna ANT, and also processes and outputs the reception signal RX received through the antenna ANT, and the duplexer ( A distortion signal detection unit 110 for detecting a distortion signal with a transmission signal TX input to the signal 100 and a signal output from the duplexer 100 to the antenna ANT, and detected by the distortion signal detection unit 110. The distortion signal removing unit 120 removes the distortion signal of the received signal RX output by the duplexer 100 as the distortion signal.

The distortion signal detector 110 may include a first coupler 111 for attenuating and outputting the transmission signal TX by a predetermined level, and a first attenuator 113 for attenuating the attenuated output signal of the first coupler 111. And a first phase shifter 115 for inverting the phase of the output signal of the first attenuator 113 and a second coupler for attenuating and outputting a signal output from the duplexer 100 to the antenna ANT by a predetermined level. 117 and a first adder 119 which adds the output signal of the first phase converter 115 to the attenuated output signal of the second coupler 117 to detect the distortion signal.

The distortion signal removing unit 120 includes a second attenuator 121 for attenuating the distortion signal output from the first adder 119 of the distortion signal detection unit 110, and an output signal of the second attenuator 121. The second phase converter 123 for inverting the phase, the amplifier 125 for amplifying the output signal of the second phase converter 123, the output signal of the amplifier 125 and the duplexer 100 outputs The second adder 127 removes the distortion signal by adding the received signal RX.

In FIG. 1, reference numerals 130 and 140 denote amplifiers for amplifying a transmission signal TX and a reception signal RX, respectively.

In the elimination circuit of the present invention configured as described above, the input transmission signal TX is amplified by the amplifier 130, is input to the duplexer 100 through the first coupler 111 of the distortion signal detection unit 110, and a predetermined value. The level is attenuated and output.

As shown in FIG. 2, the couplers 111 and 117 output a predetermined signal without being attenuated to the first output and attenuated about -10 dB to the attenuated output as the second output. Output

The transmission signal TX input to the duplexer 100 is output after being processed and output to the antenna ANT through the second coupler 117 of the distortion signal detection unit 110 and the second coupler. The output is attenuated by a predetermined level at 117.

At this time, while the duplexer 100 processes the transmission signal TX, distortion signals are generated on both the left and right sides of the transmission signal TX, and the generated distortion signal is transmitted through the antenna ANT. Filtering and removal at the repeater and / or mobile terminal has little effect on call quality.

Also, among the distortion signals generated by the duplexer 100, the upper distortion signal is all removed by a band pass filter or the like built in the duplexer 100, but the lower distortion signal is not removed and the received signal RX As it is output to the output line and degrades the call quality, the lower distortion signal output to the output line of the received signal RX should be removed.

The transmission signal TX attenuated and output from the first coupler 111 is attenuated by a predetermined level by the first attenuator 113, and the phase is inverted by the first phase converter 115 and input to the first adder 119. . The signal attenuated by the second coupler 117 is also input to the first adder 119. Then, the first adder 119 adds two input signals to remove all components of the transmission signal TX, detects the distortion signal, and outputs the distortion signal.

The distortion signal output from the first adder 119 of the distortion signal detector 110 is attenuated by a predetermined level through the second attenuator 121 of the distortion signal remover 120, and is phased by the second phase converter 123. The inverted signal is amplified by the amplifier 125 and input to the second adder 127 together with the signal of the distortion signal output by the duplexer 100. Then, the second adder 127 adds the output signal of the amplifier 125 and the reception signal RX output from the duplexer 100 to remove the distortion signal, and the signal from which the distortion signal is removed is the amplifier 140. Is printed through).

Here, a distortion signal whose phase is inverted to the upper side of the received reception signal RX remains, but the distortion signal of which the phase is inverted is simply removed by a band pass filter or the like provided at the next stage of the amplifier 140. And hardly affect the call quality.

Figure 3 is a circuit diagram showing another embodiment according to the removal circuit of the present invention. As described above, another embodiment of the present invention detects the generation amount of the distortion signal, and according to the detected generation amount, the attenuation amount of the first attenuator 113 and the second attenuator 121 and the first phase converter 115 and By automatically adjusting the phase shift angle of the second phase shifter 123, the amount of generation of the distortion signal is detected so that the amount of attenuation of the first attenuator 113 and the second attenuator 121 and the first phase shifter 115 and the second phase shifter 123 are detected. Distortion signal removal amount control means 200 for automatically adjusting the phase shift angle of the phase converter 123 is provided.

The distortion signal removal amount control unit 200 may include a third coupler 201 that attenuates and outputs a signal output from the duplexer 100 to the antenna ANT by a predetermined level, and is output from the distortion signal detection unit 110. A fourth coupler 203 for attenuating the distortion signal at a predetermined level and outputting the signal; a multiplexer 205 for selectively passing the output signals of the third coupler 201 and the fourth coupler 203; and a signal having a predetermined frequency. PLL (Phase Locked Loop) circuit 207, the mixer 209 for mixing the output signal of the multiplexer 205 and PLL circuit 207 to generate a signal of a desired frequency, and the mixer 209 The band pass filter 211 which detects a signal having a desired frequency in the output signal, the power detector 213 which detects the power of the signal output from the band pass filter 211, and the multiplexer 205 select an operation. In addition to the control box and the PLL circuit (2 07 controls the frequency of the generated signal and determines the power of the transmission signal (TX) and the distortion signal by the output signal of the power detector 213 to the first attenuator 113 and the second attenuator 121 and the It consists of a controller 215 that controls the first phase converter 115 and the second phase converter 123.

According to another exemplary embodiment of the present invention configured as described above, the third coupler 201 attenuates and outputs the signal output from the duplexer 100 to the antenna ANT by a predetermined level and is detected and output by the distortion signal detector 110. The fourth coupler 203 attenuates and outputs the distortion signal by a predetermined level, and the output signals of the third coupler 201 and the fourth coupler 203 are input to the multiplexer 205.

In this state, the controller 215 controls the multiplexer 205 to sequentially control the output signals of the third coupler 201 and the fourth coupler 203 and to control the PLL circuit 207. To generate a signal of a desired predetermined frequency.

The signal output by the multiplexer 205 and the signal of a predetermined frequency output by the PLL circuit 207 are input to the mixer 209 to be converted into a signal of mixing and a predetermined frequency, and the converted signal of the predetermined frequency is band The filter is detected by bandpass filtering in the pass filter 211, and the power level is detected by the power detector 213 and input to the controller 215.

Then, the controller 215 determines the power intensity of the transmission signal TX transmitted as the output signal of the power detector 213 and the power intensity of the generated distortion signal, and according to the determined power intensity, the first attenuator 113. And the attenuation amount of the second attenuator 121 and the phase shift angles of the first phase shifter 115 and the second phase shifter 123 to remove all the distortion signals output as the reception signal RX.

As described above, according to the present invention, the generated distortion signal is detected, and according to the detected distortion signal, the active signal according to the distortion signal generated by removing the distortion signal output to the output line of the received signal to remove all. In this case, the call quality is improved.

Claims (5)

A duplexer for processing a transmission signal and transmitting the same through an antenna, and processing and outputting a reception signal received through the antenna; A distortion signal detector for detecting a distortion signal using a transmission signal input to the duplexer and a signal output from the duplexer to the antenna; And And a distortion signal removing unit for removing the distortion signal included in the received signal output by the duplexer as the distortion signal detected by the distortion signal detecting unit. The method of claim 1, wherein the distortion signal detector; A first coupler which attenuates and transmits the transmission signal by a predetermined level; A first attenuator for attenuating the attenuated output signal of the first coupler; A first phase shifter for inverting the phase of the output signal of the attenuator; A second coupler configured to attenuate and output a signal output from the duplexer to the antenna by a predetermined level; And And a first adder configured to detect a distortion signal by adding an output signal of the phase shifter to an attenuated output signal of the second coupler, wherein the high frequency passive element intermodulation distortion signal is removed in the repeater. The method of claim 1, wherein the distortion signal removing unit; A second attenuator configured to attenuate the distortion signal output from the distortion signal detector; A second phase shifter for inverting the phase of the output signal of the attenuator; An amplifier for amplifying the output signal of the phase converter; And And a second adder configured to remove the distortion signal by adding the output signal of the amplifier and the received signal output by the duplexer. The method according to any one of claims 1 to 3, A high frequency passive element in a repeater for detecting a generation amount of the distortion signal and including a distortion signal removal amount control means for adjusting attenuation amount and phase shift angle of the distortion signal removal unit and the distortion signal detection unit according to the generation amount of the distortion signal detected. A circuit for removing intermodulation distortion signals. The method of claim 4, wherein the distortion signal removal amount control means; A third coupler configured to attenuate and output a signal output from the duplexer to the antenna by a predetermined level; A fourth coupler configured to attenuate and output a distortion signal outputted from the distortion signal detector by a predetermined level; A multiplexer for selectively passing the output signals of the third and fourth couplers; A PLL circuit for generating a signal of a predetermined frequency; A mixer for mixing output signals of the multiplexer and the PLL circuit to generate a signal having a desired frequency; A band pass filter for detecting a desired frequency signal from the output signal of the mixer; A power detector detecting power of a signal output from the band pass filter; And The distortion signal removing unit and the distortion signal detecting unit are configured to control the selection operation of the multiplexer, control the frequency of the signal generated by the PLL circuit, and determine the power of the transmission signal and the distortion signal using the output signal of the power detector. A circuit for removing high frequency passive element intermodulation distortion signals in a repeater, comprising a controller for controlling attenuation amount and phase shift angle.