KR20130134817A

KR20130134817A - Noise cancellation amplifier

Info

Publication number: KR20130134817A
Application number: KR1020120058616A
Authority: KR
Inventors: 김사훈
Original assignee: 김사훈
Priority date: 2012-05-31
Filing date: 2012-05-31
Publication date: 2013-12-10

Abstract

The present invention relates to a noise offsetting amplifier used for a base station antenna. The invention includes a first duplexer for separating a delivery path of a wireless frequency signal transceived through an antenna, a combiner outputting the signal outputted from the first duplexer by dividing it into two wireless frequency signals, a first low noise amplifier outputting one of the two signals by removing a noise from the signal and amplifying it at a set amplification level, a band offsetting filter outputting a remaining wireless frequency signal outputted from the combiner by selectively removing only a main signal, a phase shifter shifting a phase of a noise signal outputted from the band offsetting filter, a mixer outputting the wireless frequency signal outputted from the first low noise amplifier and the wireless frequency signal outputted from the phase shifter by mixing them, and a second duplexer delivering the wireless frequency signal outputted from the mixer to a communication unit and delivering the signal to the first duplexer. According to this, the performance of a base station is improved by removing a noise from the wireless frequency signal received through the antenna. [Reference numerals] (100) Antenna;(200) Communication unit

Description

Noise Cancellation Amplifier

The present invention relates to a radio frequency amplifier, and more particularly, to a noise canceling amplifier used in a base station antenna.

With the rapidly evolving modern industries, customer needs are diversified and sophisticated, and convergence and integration technologies are emerging to address this.

In particular, in the broadcasting and telecommunications industry through radio waves, various frequencies are used to service customers' endless needs, and the space is filled with various electromagnetic waves.

High power amplifiers are used to deliver electromagnetic waves over long distances from base stations and repeaters in mobile communications services.

However, electromagnetic waves propagated at high outputs generate an environment called propagation noise other than the radio waves to be transmitted in the mobile communication service.

These propagation noises are amplified in the amplifier along with the main signal across the antenna in the mobile communication base station and the repeater, so that the noise level in the mobile communication system rises like the main signal, resulting in a poor ratio of noise to the main signal.

In order to prevent such a catch rate from becoming worse, base stations and repeaters prevent the signal from outputting more than a certain output, which in turn lowers the service efficiency of the mobile communication network and increases the number of base stations and repeaters. .

On the other hand, the recent evolution of mobile communication is rapidly progressing from voice service to fast and smooth data service.

As a result, service providers face the challenge of increasing frequency efficiency by increasing the ratio of noise signals to main signals in base stations and repeaters in order to increase the transmission speed of wireless mobile communication data.

As shown in FIG. 1, the base station implements a base station in a tower form to minimize the influence of surrounding terrain, thereby making the antenna 10 position as high as possible, and thus, a ground communication unit 20 may be used. And an antenna 10 are connected by a long coaxial cable 30.

The weak signal received through the antenna 10 may be further weakened while being transmitted to the communication unit 20 in charge of signal processing through the long coaxial cable 30.

In order to solve this problem, a mobile communication service provider has been using a system in which an amplifier is mounted in close proximity to the antenna 10, and amplifies an incoming signal primarily and transmits the signal to the communication unit 20 through the coaxial cable 30.

As such, an amplifier installed in close proximity to the antenna 10 is referred to as a TMA (Tower Mounted Amplifier) 40. The TMA 40 is simply installed in close proximity to the antenna 10, as shown in FIG. Since only the low-noise amplifier 45 amplifies the noise signal as well as the signal to be delivered, there is a problem that cannot be a solution to the noise described above.

Republic of Korea Patent Publication No. 10-884250

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and when installed in close proximity to an antenna, when amplifying and sending a frequency signal from an antenna to a communication unit, it can suppress noise as much as possible and amplify only a required signal. The purpose is to provide a noise canceling amplifier.

Noise canceling amplifier according to an embodiment of the present invention for achieving the above object, the first duplexer for separating the transmission path of the radio frequency signal transmitted and received through the antenna; A combiner for dividing the radio frequency signal output from the first duplexer into two radio frequency signals; A first low noise amplifier which receives one radio frequency signal from two radio frequency signals output from the combiner and amplifies and outputs the amplified level after noise reduction; A band attenuation filter which receives the remaining radio frequency signals output from the combiner and selectively removes only the main signal and outputs the main signal; A phase shifter for shifting the phase of the noise signal output from the band attenuation filter out of phase with the main signal; A combiner for combining and outputting a radio frequency signal output from the first low noise amplifier and a radio frequency signal output from the phase shifter; And a second duplexer which transmits a radio frequency signal output from the combiner to a communication unit and delivers the radio frequency signal received from the communication unit to the first duplexer.

And a delay element for delaying the radio frequency signal output from the first low noise amplifier and synchronizing with the radio frequency signal output from the phase shifter.

And a second low noise amplifier which receives the radio frequency signal output from the phase shifter and amplifies the radio frequency signal to a predetermined amplification level.

According to the noise canceling amplifier of the present invention, it is possible to amplify only the main signal among the radio frequency signals received through the antenna and to minimize the noise signal.

In addition, it is possible to maximize the efficiency of the amplifier by selectively amplifying the frequency, it is possible to maximize the frequency efficiency by providing a base for smooth signal processing in the communication unit (Radio Unit).

1 is a view for explaining a conventional technique;
Figure 2 is a schematic view showing the configuration of a conventional TMA.
3 is a diagram schematically illustrating a configuration of a noise canceling amplifier according to an embodiment of the present invention.
4 is a diagram illustrating a process of removing noise by a noise attenuation amplifier according to an embodiment of the present invention.

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

3 is a diagram schematically illustrating a configuration of a noise canceling amplifier according to an exemplary embodiment of the present invention.

As shown in FIG. 3, the noise canceling amplifier 300 according to an embodiment of the present invention is installed close to the rear end of the antenna 100 of the tower base station, and includes a first duplexer 310 and a combiner. 320, the first low noise amplifier 330, the delay line 340, the band attenuation filter 350, the phase shifter 360, the second low noise amplifier 370, and the combiner 380. ), And a second duplexer 390.

In such a configuration, the first duplexer 310 separates a transmission path of radio frequency signals transmitted and received through the antenna 100, and transfers the radio frequency signals received through the antenna 100 to the combiner 320. The radio frequency signal received from the second duplexer 390 is transmitted to the antenna 100.

As described above, the first duplexer 310 may be implemented as a surface acoustic wave filter, a dielectric filter, a cavity filter, or the like.

The combiner 320 divides the radio frequency signal output from the first duplexer 310 into two radio frequency signals, one to the first low noise amplifier 330, and the other to the band attenuation filter 350. do.

As described above, the combiner 320 is meant to include all irrespective of what has a function of dividing the radio frequency signal, including the OPAMP.

The first low noise amplifier 330 receives one radio frequency signal from two radio frequency signals output from the combiner 320 and amplifies the signal to a predetermined amplification level after removing noise.

The delay line 340 delays the radio frequency signal output from the first low noise amplifier 330 for a predetermined time to synchronize the radio frequency signal output from the phase shifter 360.

The band attenuation filter 350 receives the remaining radio frequency signals output from the combiner 320 and selectively removes only the main signal to output.

The band attenuation filter 350 described above may be implemented as a surface acoustic wave filter, a dielectric filter, a cavity filter, or the like.

The phase shifter 360 shifts the phase of the noise signal output from the band attenuation filter 350 so as to be out of phase with the main signal.

As described above, the phase shifter 360 is meant to include all irrespective of what has a function that can change the phase of the radio frequency signal.

The phase shifter 360 also includes a phase shifter composed of a resistor, an inductor, and a capacitor.

The second low noise amplifier 370 receives the radio frequency signal output from the phase shifter 360, removes noise, and amplifies the signal to a predetermined amplification level.

The combiner 380 is a radio frequency signal output from the first low noise amplifier 330 and input through the delay line 340 and a radio frequency output from the phase shifter 360 and input through the second low noise amplifier 370. Output the combined signal.

As such, the radio frequency signal output from the first low noise amplifier 330 and input through the delay line 340 and the radio frequency signal output from the phase shifter 360 and input through the second low noise amplifier 370 may be used. In combination, an amplified main signal with minimal noise can be obtained.

The second duplexer 390 transmits the radio frequency signal output from the combiner 380 to the communication unit 200 which performs signal processing, and transmits the radio frequency signal received from the communication unit 200 to the first duplexer.

The second duplexer 390 may be implemented as a surface acoustic wave filter, a dielectric filter, a cavity filter, or the like.

4 is a diagram for describing a process of removing noise by a noise attenuation amplifier according to an embodiment of the present invention.

First, when the radio frequency signal is received through the antenna 100 of the tower base station, the radio frequency signal coming into the reception frequency through the first duplexer 310 is divided into two radio frequency signals in the combiner 320, one Is applied to the first low noise amplifier 330, and the other is applied to the band attenuation filter 350.

As described above, the first low noise amplifier 330 receiving the radio frequency signal from the combiner 320 removes noise from the received radio frequency signal and amplifies the signal to a predetermined amplification level.

In addition, the band attenuation filter 350 receiving the radio frequency signal from the combiner 320 selectively removes and outputs only the main signal from the received signal, and the radio frequency signal from which the main signal is removed is the first low noise amplifier 330. After phase-processing 180 degrees through the phase shifter 360 so that the phase of the radio frequency signal outputted from the phase is reversed, it is amplified again by the second low noise amplifier 370 so that the noise signal is reduced by the first low noise amplifier 330. The same size as the noise signal included in the radio frequency signal output from the) is applied to the combiner 380.

In this case, as shown in FIG. 4, the radio frequency signal applied to the combiner 380 is a signal amplified by the main signal being attenuated by the band attenuation filter 350 and only the peripheral signal (noise signal) is processed 180 degrees in phase.

When the combiner 380 is combined with the signal amplified by the first low noise amplifier 330, the phase is shifted by 180 degrees in the band excluding the main signal, so that the noise signal can output only the signal (amplified signal) that is cleanly removed. Will be.

The noise canceling amplifier of the present invention is not limited to the above-described embodiment, and can be implemented in various modifications within the range allowed by the technical idea of the present invention.

100. antenna, 200. communication unit,
300. noise canceling amplifier, 310. first duplexer,
320. Coupler, 330. The first low noise amplifier,
340. delay line, 350. band attenuation filter,
360. Phase Shifter, 370. Second Low Noise Amplifier,
380. Combiner, 390. Second Duplexer

Claims

A first duplexer for separating a transmission path of radio frequency signals transmitted and received through an antenna;
A combiner for dividing the radio frequency signal output from the first duplexer into two radio frequency signals;
A first low noise amplifier which receives one radio frequency signal from two radio frequency signals output from the combiner and amplifies and outputs the amplified level after noise reduction;
A band attenuation filter which receives the remaining radio frequency signals output from the combiner and selectively removes only the main signal and outputs the main signal;
A phase shifter for shifting the phase of the noise signal output from the band attenuation filter out of phase with the main signal;
A combiner for combining and outputting a radio frequency signal output from the first low noise amplifier and a radio frequency signal output from the phase shifter; And
And a second duplexer which transmits a radio frequency signal output from the combiner to a communication unit and delivers the radio frequency signal received from the communication unit to the first duplexer.

2. The noise canceling amplifier of claim 1, further comprising a delay element for delaying a radio frequency signal output from the first low noise amplifier and synchronizing with a radio frequency signal output from the phase shifter.

The noise canceling amplifier of claim 1, further comprising a second low noise amplifier which receives the radio frequency signal output from the phase shifter and amplifies the radio frequency signal to a predetermined amplification level.