KR20020004344A - An improvement of passive intermodulation distortion with coupling loop - Google Patents

Abstract

PURPOSE: An apparatus for enhancing passive intermodulation distortions is provided to minimize the effects of passive intermodulation products generated from a duplexer by using a feedback loop and a phase shifter. CONSTITUTION: An apparatus for enhancing passive intermodulation distortions is comprised of a power amplification part(10), a coupler(20), a filter(30), a variable gain control part(40), a phase adjustment part(50), a low noise amplification part(60), a signal combination part(70), and a duplexer(80). The power amplification part(10) finally amplifies RF signals to be transmitted. The coupler(20) extracts a part of the amplified signals. The filter(30) removes other signals except a using frequency band. The variable gain control part(40) amplifies or decreases a signal in order to adjust the size of the signal. The phase adjustment part(50) adjusts the phase of a signal in order to get a desired phase difference from another signal. The low noise amplification part(60) executes low noise amplification to improve the noise characteristic of a received signal. The signal combination part(70) combines two signals in two different paths through an identical path. The duplexer(80) has a combined characteristic of transmit/receive band pass filters.

Description

Passive device intermodulation distortion improvement device {AN IMPROVEMENT OF PASSIVE INTERMODULATION DISTORTION WITH COUPLING LOOP}

In the duplexer used in a mobile communication base station and a repeater, the present invention can reduce the reception sensitivity and reduce the subscriber sensitivity by generating an intermodulation component of a passive element generated by a large transmission power, an antenna, and a surrounding environment as an interference signal. A device for improving the reduction in capacity is provided.

A conventional technique for minimizing the level of the intermodulation component of the passive element generated in the duplexer is a method of improving the intermodulation characteristics to some extent by plating the connector of the input and output terminal of the duplexer. However, according to this conventional technique, a new plating technique is required, and the unit cost of components is not only increased, but the improvement is not achieved to the extent that the fundamental intermodulation characteristics are satisfied.

Another conventional technique for minimizing the influence of the intermodulation component is to use the transmit / receive filter and the antenna, respectively, without using a duplexer to reduce the influence of the passive element intermodulation component of the reception band generated in the transmitter filter. There is a way to reduce it. However, this method has the effect of reducing the influence of the passive element intermodulation components, but since the separate transmission and reception filters are used, a transmission antenna, a reception antenna and a corresponding power feeding cable are also required. However, there is a disadvantage that the installation cost increases.

Accordingly, in order to solve the above-mentioned problems of the prior art, the present invention uses a kind of feedback loop and a phase shifter as the intermodulation component of the passive element generated in the duplexer. Disclosed are devices that minimize the impact.

According to the present invention, it is possible to improve the installation cost of the mobile communication base station and repeater by improving the problem that the intermodulation component of the passive element generated by the large transmission power, the antenna and the surrounding environment occurs in the reception band in the conventional duplexer. It can reduce and increase the frequency use efficiency.

1 is a diagram illustrating an apparatus for improving passive element intermodulation distortion using intermodulation signals of an output stage of a power amplifier according to an exemplary embodiment of the present invention.

2 to 3 show a passive element intermodulation distortion improvement apparatus of another embodiment of the present invention shown in FIG.

4 is a diagram illustrating an apparatus for improving passive element intermodulation using an intermodulation signal at a duplexer output stage according to another embodiment of the present invention.

5 to 6 show a passive element intermodulation distortion improvement apparatus of another embodiment of the present invention shown in FIG.

<Explanation of symbols for the main parts of the drawings>

10: power amplifier

20: coupler

30: filter

40: variable gain control unit

50: phase adjuster

60: low noise amplifier

70: signal coupling unit

80: duplexer

The present invention for achieving the above object is a power amplifier 10 consisting of a power amplifier that functions to finally amplify a radio signal to be transmitted in a wireless communication system, a coupler for extracting a portion of the amplified radio signal ( 20), the filter 30 to remove other signals outside the frequency band used, the variable gain control unit 40 to amplify or reduce the signal for controlling the size of the signal, the desired phase with the other signal by adjusting the phase of the signal Low noise amplifier 60 consisting of a phase adjuster 50 for adjusting the difference, a low noise amplifier for low noise amplification of the received signal at the receiving end to improve the noise characteristics of the received signal, the same signal to the two signals of different paths The signal combiner 70, which combines the paths of the transmission and reception bandpass filters, combines the characteristics of the transmit / receive bandpass filter, and amplifies the power. The intermodulation signal of the negative output terminal is used or the intermodulation signal of the duplexer output terminal is used.

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

1 is a diagram illustrating an apparatus for improving passive element intermodulation distortion using intermodulation signals of an output stage of a power amplifier according to an exemplary embodiment of the present invention.

In FIG. 1, after extracting the amplified signal from the power amplifier 10, which amplifies the signal to be finally transmitted, to the coupler 20, another signal is left using only the filter 30, leaving only the intermodulated signal in the reception band. Remove everything. In addition, the signal passing through the power amplifier 10 and the coupler 20 is input to the duplexer 80, the passive element intermodulation component generated by the duplexer 80 and the antenna is a low noise amplification It is input to the unit 60. The signal passing through the low noise amplifier 60 is combined in the signal combiner 70. The signal passing through the filter 30 is adjusted in the variable gain adjusting unit 40 so that its amplitude is the same as the signal amplified in the low noise amplifier 60, and then in the variable gain adjusting unit 40 The adjusted signal is adjusted in phase by the phase adjuster 50 such that a phase difference from the signal passed through the low noise amplifier 60 is 180 °. When these two signals are input to the signal combiner 70, at the output terminal of the signal combiner 70, two signals having the same magnitude and 180 [deg.] Phase difference cancel each other out. This eliminates the intermodulation components in the reception band generated by the duplexer.

2 to 3 illustrate a passive element intermodulation distortion improving apparatus of another embodiment of the present invention shown in FIG. As shown in FIG. 2, in another embodiment of the present invention illustrated in FIG. 1, the positions of the phase adjuster 50 and the variable gain adjuster 40 may be replaced with each other. According to the exemplary embodiment shown in FIG. 2, after the phase of the signal is changed to 180 ° in the phase adjuster 50, the size of the signal is adjusted in the variable gain adjuster 40.

In addition, as shown in FIG. 3, the phase adjuster 50 may be located behind the duplexer 80 and the low noise amplifier 60.

4 is a diagram illustrating a passive device intermodulation improvement apparatus using a intermodulation signal of a duplexer output stage according to another embodiment of the present invention. In FIG. 4, after extracting the intermodulation component signal of the passive element generated by the duplexer 80 to the coupler 20, the filter 30 is used to remove all other signals except for the intermodulation signal in the reception band. . The filtered signal is generated in the duplexer 80 and is inputted to the low noise amplifier 60 and has the same magnitude as that of the signal being amplified and has a 180 ° difference in phase. The phase is adjusted and the phase is adjusted in the phase adjuster 50. By doing so, in the signal combiner 70, two signals having the same magnitude and 180 [deg.] Phase difference cancel each other out.

5 to 6 illustrate a passive element intermodulation distortion improving apparatus of another embodiment of the present invention shown in FIG. As shown in FIG. 5, in another embodiment of the present invention illustrated in FIG. 4, the positions of the phase adjuster 50 and the variable gain adjuster 40 may be replaced with each other. According to the exemplary embodiment shown in FIG. 5, after the phase of the signal is changed to 180 ° in the phase adjuster 50, the size of the signal is adjusted in the variable gain adjuster 40.

In addition, as shown in FIG. 6, the phase adjuster 50 may be located behind the duplexer 80 and the low noise amplifier 60.

The foregoing has been described to enable those skilled in the art to easily practice the invention in accordance with the illustrated embodiments, and is described in accordance with patent requirements. Those skilled in the art will be able to make various modifications to the illustrated embodiment, and the general wintry disclosed herein may equally apply to other embodiments. Thus, the illustrated embodiments are not intended to limit the invention to these embodiments, but to cover the widest scope consistent with the principles and features described herein.

According to the present invention, the installation cost of a mobile communication base station and a repeater is fundamentally improved by a fundamental improvement in the problem that a large transmission power, an intermodulation component of a passive element generated by an antenna and a surrounding environment occur in a reception band in a conventional duplexer. Can be greatly reduced and the frequency usage efficiency can be increased.

Claims (6)

In the passive element intermodulation distortion improvement device, A power amplifier 10 for finally amplifying the radio signal to be transmitted; A coupler 20 for extracting a portion of the amplified radio signal; A filter 30 for removing signals other than the frequency band used; Variable gain control unit 40 for amplifying or reducing the signal for controlling the size of the signal, Phase adjuster 50 for adjusting the phase of the signal to adjust the desired phase difference with the other signal, A low noise amplification unit 60 for low noise amplifying the signal received at the receiver to improve noise characteristics of the received signal; A signal combiner 70 for combining two signals of different paths into the same single path; Duplexer 80 combines the characteristics of a transmit / receive bandpass filter It includes, and as using the signal of the output terminal of the power amplifier 10, the signal of the two input terminals of the signal coupling unit 70 is equal in magnitude and phase 180 ° difference between the signal coupling unit 70 Passive device intermodulation distortion improvement device, characterized in that to cancel the intermodulation component at the output terminal of. The apparatus of claim 1, wherein the signal passing through the filter (30) passes through the phase adjuster (50) and the variable gain adjuster (40) in order. The passive element mutual distortion reduction apparatus according to claim 1, wherein the phase adjuster (50) is located between the low noise amplifier (60) and the signal combiner (70). In the passive element intermodulation distortion improvement device, A power amplifier 10 for finally amplifying the radio signal to be transmitted; A coupler 20 for extracting a portion of the wireless signal; A filter 30 for removing signals other than the frequency band used; Variable gain control unit 40 for amplifying or reducing the signal for controlling the size of the signal, Phase adjuster 50 for adjusting the phase of the signal to adjust the desired phase difference with the other signal, A low noise amplifier 60 for low noise amplifying the received signal to improve noise characteristics of the received signal; A signal combiner 70 for combining two signals of different paths into the same single path; Duplexer 80 combines the characteristics of a transmit / receive bandpass filter Passive device intermodulation distortion improvement device comprising a, characterized in that for using the intermodulation signal of the duplexer (80) output terminal. 5. The passive element mutual distortion improvement apparatus according to claim 4, wherein the signal passing through the filter (30) passes through the phase adjuster (50) and the variable gain adjuster (40) in order. 5. The passive element mutual distortion reduction apparatus according to claim 4, wherein the phase adjuster (50) is located between the low noise amplifier (60) and the signal combiner (70).