KR101131923B1 - Power output unit with an interference suppress system filter unit and adaptive feedforward linearizer for mobile telecommunication equipments - Google Patents

Abstract

The present invention increases the adjacent channel leakage facility in the interference suppression system filter unit so as to have high separation from other frequency bands, and further adds an adaptive feedforward linearization circuit to remove the intermodulation distortion (IMD) of the power amplifier which is a nonlinear device. Thus, to provide an output terminal of the mobile communication device that can increase the adjacent channel leakage facilities and linearity at the same time to increase the efficiency in two steps.

The technical configuration includes a driving amplifier receiving an RF analog frequency signal received through an antenna or a plurality of antennas and converting the RF analog frequency signal into a frequency signal having a constant gain and power; Passing or stopping the frequency signal input through the driving amplifier, increasing the adjacent channel leakage equipment (ACLR) by compensating and removing interference signals and ripples except the frequency band passed or blocked, and a constant gain and An interference suppression system filter module converting the frequency signal into power; A power amplifier which amplifies the power of the frequency signal output from the interference suppression system filter module, converts the power into a frequency signal having a predetermined power and gain, and outputs the radiation power through an antenna; A frequency signal output from the interference suppression system filter module and a power amplifier is input, and an output signal of the power amplifier is removed from the output signal of the interference suppression system filter module to amplify only an intermodulation distortion (IMD), and the power amplifier And an adaptive feedforward linearization circuit for linearizing the output signal of the power amplifier by removing the amplified intermodulation distortion (IMD) from the signal output from the power amplifier.

Description

OUTPUT UNIT WITH AN INTERFERENCE SUPPRESS SYSTEM FILTER UNIT AND ADAPTIVE FEEDFORWARD LINEARIZER FOR MOBILE TELECOMMUNICATION EQUIPMENTS}

The present invention relates to an output terminal of a mobile communication device, and in particular, to maximize the characteristics of adjacent channel leakage facilities so as to have high separation from other frequency bands, and to completely remove nonlinearities of the power amplifier. The present invention relates to an output terminal of a mobile communication device to which an adaptive feedforward linearization circuit and an interference suppression system filter unit, which can maximize linearity by amplifying and removing an IMD) from an original signal.

In general, a transmitter (TX) of a mobile communication device converts a transmission signal including data into a high frequency signal, amplifies the signal with appropriate power, and transmits the signal without interference from other frequencies. After filtering and receiving only desired frequency bands from noise and interference signals, amplifying weak signals while minimizing noise to generate usable sizes, and reducing the frequency of the converted high frequency signals to recover the actual signals.

Here, the transmitter should send out the proper end stage power enough to receive the signal at the receiving end, and should not emit components other than the frequency to be transmitted, and should be able to export without interference when using multiple frequency channels. .

In addition, since the receiver must amplify the weak signal transmitted from the transmitter, a multi-stage amplification stage is required, and in order to suppress various noise and interference signals in the air as much as possible, and to select the desired channel accurately when using multiple frequency channels, And it should prevent or filter out various frequency components from outside.

In other words, since the atmosphere is a medium in which various frequency signals are emitted and traveled, electromagnetic waves have a lot of noise and are attenuated by various elements in the atmosphere. (W)) and gain (Gain, dB) should be sent.

Here, the output power efficiency of the base station and the repeater, which are mobile communication devices, is very low at about 10%, which means that 200W of power is required to obtain 20W of RF signal output. The remaining 200W-20W = 180W means that it is converted to heat and released into the atmosphere by the heat release device.

In addition, the heat dissipation device uses a heat sink and a heat sink such as a fan or air conditioner, and the heat sink and heat sink occupy 30% of the total weight and volume of the mobile communication device, so that the efficiency of the output stage is increased. With the economics of power supply, the weight and volume of mobile communication devices can be reduced.

On the other hand, the power efficiency of the output terminal of the mobile communication device is low because the characteristics of the communication signal must meet the Adjacent Channel Leakage Power Ratio (ACLR), which does not affect other channels or frequencies.

Here, referring to FIG. 1, the adjacent channel leakage facility is an index indicating a linearity of a power amplifier (PA), and in WCDMA, a standard specification indicating a linearity of a power amplifier. The difference in power is expressed in dBc, and the result is the same as that of the adjacent channel leakage facility (ACPR).

FIG. 2 is a diagram schematically illustrating output stages of a base station and a repeater according to the prior art, and FIG. 3 is a graph showing the output spectral density of a single channel output of the communication apparatus according to the prior art. As shown in FIGS. 2 and 3, an input signal of a power amplifier (PA) is amplified by a driving amplifier (DA) in front of it.

The power value of the input signal of the power amplifier, which is the output of the driving amplifier, is about 0 to 10 dBm, and the gain of the output signal of the power amplifier is about 30 dB to 50 dB.

The efficiency of the power amplifier increases as it approaches the saturation point, which is the highest value the power amplifier can afford. In this case, the power amplifier enters the nonlinear characteristic region, so the characteristic of the output signal is high in spectrum. Due to growth, the adjacent channel leakage equipment is distorted.

Therefore, in order to minimize such damage, the efficiency is lowered to operate the power amplifier in a region where linearity is ensured.

In this case, the characteristics of the output signal including adjacent channel leakage facilities are directly influenced by the characteristics of the input signal as well as the characteristics of the power amplifier. The above description is based on the assumption that the characteristics of the input signal are the same.

In addition, the characteristics of the transistor constituting the power amplifier is between 25% to 35% higher than the above-mentioned efficiency, and when designed under optimum conditions, the efficiency of the transistor can be obtained up to 50%, and the gain of the transistor at this time Is approximately 8 dB to 20 dB.

On the other hand, the output characteristics of the existing mobile communication device is determined by the difference between the signal size in the desired band and the noise out of the band, it may be represented by the isolation (Isolation) characteristics, and recently referred to as the adjacent channel leakage facilities. In the following description, it is assumed that the adjacent channel leakage facility is a concept including the isolation.

In order to increase the output efficiency of the mobile communication device, the gain must be increased. The amplification in the device does not only amplify a signal within a desired band, but also amplifies noise outside a desired band. The better the leakage ratio characteristic, the larger the gain can be amplified, and thus the desired output can be obtained.

Referring to FIG. 2, the gain of the last power amplifier of the output terminal of the mobile communication device is designed to be 30 dB to 50 dB, in which case the output signal of the drive amplifier, that is, the characteristic (ACLR) of the input signal of the power amplifier PA is relatively high. Even better, the signal and noise are amplified from 30dB to 50dB in the last power amplifier, resulting in distortion in the ACLR characteristics of the last output signal.

To compensate for this, power amplifiers must be designed to operate in areas of low efficiency, that is, in the area of linearity.

In order to solve this problem, Korean Laid-Open Patent Publication No. 2002-0023007 discloses a linear amplification circuit used in a base station of a mobile communication system, which will be described with reference to FIG. 4.

4 is a splitter 10 which separates an RF signal received from a mobile station, and a first to fourth power amplifiers 20-1? A power amplifier 20 for high power amplification of each RF signal separated by the splitter 10, and first to fourth power amplifiers 20-1 to 4 in the power amplifier 20; Delay, phase reversal, and gain adjustment for the combiner 30, the RF signal inputted to the splitter 10, and the RF signal outputted from the combiner 30, respectively. The feedforward linearization circuit 40 removes noise such as IMD component and spurious generated during high power amplification of the RF signal through the same feedforward linearization operation, and noise of IMD component generated while passing through the combiner 30. It is composed.

Here, the feedforward linearization circuit 40 may include a first coupler 41-1 coupling the RF signal input to the splitter 10 and an RF signal coupled by the first coupler 41-1. A first delayer 42-1 for delaying a predetermined time, a first phase inverter and a gain adjuster for inverting a phase and adjusting gain with respect to an RF signal output after being delayed by the first delayer 42-1 43-1, a second coupler 41-2 coupling the RF signal mixed with the noise signal output from the combiner 30, and noise coupled by the second coupler 41-2. A third coupler 41-3 and the third coupler for re-coupling the mixed RF signal and combining the RF signal output from the first phase inversion and gain adjuster 43-1 to generate a pure noise signal A second phase inversion and gain adjuster 43-2 for inverting phase and adjusting gain with respect to the pure noise signal generated through 41-3; An error amplifier 44 for amplifying the noise signal output from the two-phase inversion and gain adjuster 43-2, and the RF signal mixed with the noise signal coupled by the second coupler 41-2 for a predetermined time. The second delayed delay 42-2 and the delayed by the second delay 42-2, the noise signal output from the error amplifier 44 by re-coupled the RF signal mixed with the noise signal is output And a fourth coupler 41-4 for generating a pure RF signal.

However, in the case of an output stage using a feedforward linearization circuit according to the prior art, the efficiency is higher than the output stage without using the same, but the higher the efficiency of the output stage can be derived a technique applying various advantages, in the present invention By applying a configuration in which the interference suppression system filter unit is further added to the feed forward linearization circuit according to the prior art, synergistic effects are induced by the linearization of the feedforward linearization circuit and the increase of adjacent channel leakage facilities of the interference suppression system filter unit. In order to achieve higher output stage efficiency than when each method is applied.

In order to completely remove the non-linearity of the power amplifier, it is only to amplify only the intermodulation distortion signal of the output of the power amplifier to subtract from the signal output from the power amplifier, to completely eliminate the distortion signal. It is an object of the present invention to provide an output stage of a mobile communication device to which an adaptive feedforward linearization circuit and an interference suppression system filter unit capable of maximizing linearity by removing the same are provided.

Another object of the present invention is to maximize the characteristics of the adjacent channel leakage facility so that the frequency signal input to the power amplifier is different from other frequency bands, and adjust the gains of the driving amplifier and the power amplifier to the most desirable, so that the power amplifier is in a nonlinear region. It is to provide an output terminal of a mobile communication device to which an adaptive feedforward linearization circuit and an interference suppression system filter unit, which can be operated even in the linear domain, can have the same effect.

Another object of the present invention is to increase the power efficiency so that most of the input power is not converted to heat, and accordingly to remove and minimize the heat sink and the heat sink to reduce the size and weight of the device including the base station and the repeater mobile communication device The present invention provides an output terminal of a mobile communication device to which an adaptive feedforward linearization circuit and an interference suppression system filter unit, which can achieve miniaturization, are applied.

In order to achieve the above object, the present invention provides a drive amplifier for receiving an RF analog frequency signal received through an antenna or a plurality of antennas and converts the signal into a frequency signal having a constant gain (Gain) and power (Power); Passing or stopping the frequency signal input through the driving amplifier, increasing the adjacent channel leakage equipment (ACLR) by compensating and removing interference signals and ripples except the frequency band passed or blocked, and a constant gain and An interference suppression system filter module converting the frequency signal into power; A power amplifier which amplifies the power of the frequency signal output from the interference suppression system filter module, converts the power into a frequency signal having a predetermined power and gain, and outputs the radiation power through an antenna; A frequency signal output from the interference suppression system filter module and a power amplifier is input, and an output signal of the power amplifier is removed from the output signal of the interference suppression system filter module to amplify only an intermodulation distortion (IMD), and the power amplifier And an adaptive feedforward linearization circuit for linearizing the output signal of the power amplifier by removing the amplified intermodulation distortion (IMD) from the signal output from the power amplifier.

The power amplifier may be connected in parallel with the interference suppression system filter module between the interference suppression system filter module and the power amplifier.

In this case, the adaptive feedforward linearization circuit may include a first coupler for extracting a part of an output signal of the interference suppression system filter module; A first time delayer for delaying an output signal of the first coupler for a predetermined time; A second coupler for extracting a part of a frequency signal including intermodulation distortion (IMD) from the power amplifier; A first combiner which subtracts the output signal of the second coupler from the output signal passed through the first delay and outputs the intermodulation distortion (IMD) in a negative direction; An error amplifier for amplifying the amount of intermodulation distortion output from the first combiner; A second time delay delaying the output signal of the power amplifier for a predetermined time; And a second combiner for summing the power of the second time delay and error amplifier.

In addition, the gain of the power amplifier is within the range that can produce a linear output in the region having a linearity and / or non-linearity because the adjacent channel leakage equipment of the signal output from the interference suppression system filter module is high. do.

The gain of the driving amplifier may have a gain obtained by subtracting the sum of the gain of the power amplifier, the gain or the loss of the interference suppression system filter module from the total gain of the output stage.

The interference suppression system filter unit may include one or more interference suppression system filter modules configured to pass and block a frequency signal of a predetermined band, and to amplify the frequency signal. And a compensation circuit for stopping and compensating a ripple band generated by the filter module that compensates for the interference signal.

In addition, the one or more interference suppression system filter module; Two or more series-connected filters having the same characteristics to pass and stop a frequency band signal; It characterized in that it comprises an LNA provided to compensate for the insertion loss generated according to the stop band in the filter.

And, the filter is characterized in that formed of any one of a dielectric or metal cavity (Metal Cavity) or DR-metal cavity or stripline.

The filter is characterized in that it consists of a combination of a dielectric or metal cavity or a dielectric resonance-metal cavity or stripline.

In addition, the LNA has a gain according to the insertion loss, and is connected in series with the filter to compensate for the insertion loss generated in the filter.

The compensation circuit may include a filter that blocks an amplitude equal to the magnitude of the ripple in the frequency band in which the ripple occurs so as to compensate for the ripple generated in the interference suppression system filter module.

Here, the filter is characterized in that the BSF (Band Stop Filter) to block the amplitude of the ripple generated frequency band and the amplitude of the ripple.

In addition, the filter is characterized in that the directional filter (Directional Filter) to block the amplitude as much as the size of the ripple generated frequency band and ripple.

In addition, the power amplifier is characterized by consisting of a power transistor (Power Transistor) consisting of a MOSFET or gallium nitride (GaN).

Preferably, the output terminal of the mobile communication device further comprises a low noise amplifier for amplifying RF signals received by the antenna or a plurality of antennas in front of the driving amplifier.

As described above, the present invention having the above-described configuration includes amplifying only an intermodulation distortion (IMD) signal among the nonlinear output signals of the power amplifier, which is a nonlinear element, and subtracting it from the output signal of the power amplifier. The noise of interference signal, intermodulation distortion, etc. can be completely eliminated, and the interference suppression system filter unit improves the characteristics of adjacent channel leak facilities, so that the separation degree can be increased so that there is no noise and interference with other bands, Since the gain can be increased without considering the adjacent channel characteristic ratio in the driving amplifier, even if it is operated in the linear or nonlinear region in the power amplifier, it can have the same effect as operating in the linear region, and power-to-output supplied to the power amplifier. By increasing the efficiency of the power supply, the power lost to heat is minimized Sikkim increase the efficiency and at the same time remove the heat shield and the heat sinks and the like to minimize can achieve the effects of which can be miniaturized in size and volume of the mobile communication device.

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

5 is a diagram illustrating an output terminal of a mobile communication device to which an adaptive feedforward linearization circuit and an interference suppression system filter unit according to the present invention are applied. As shown in FIG. 5, an output terminal of the mobile communication apparatus to which the adaptive feedforward linearization circuit and the interference suppression system filter module according to the present invention are applied includes a driving amplifier (DA) 10 and an interference suppression system filter unit (ISS FU). Suppress System Filter Unit (30), power amplifier (50), adaptive feedforward linearizer (AFL: Adaptive Feedforward Linearizer, 70).

Here, since the driving amplifier 10 does not satisfy both the gain and power efficiency in the power amplifier 50, a high gain in the front end to drive the power amplifier 50 is obtained. ) To compensate for the gain of the power amplifier 50.

The gain of the drive amplifier 10 in the present invention is designed to be 60dB to 70dB, provided for gain compensation rather than power efficiency, to supply an input signal of sufficient magnitude required for the power amplifier 50.

In addition, since the power amplifier 50 must transmit a high power to a signal to be radiated to the air through the antenna ANT at the output terminal, if the high power is compensated by the power amplifier 50, the high gain is the drive amplifier ( 10) to compensate.

In addition, the interference suppression system filter unit (ISS FU) 30 according to the present invention is characterized by low insertion loss in the operating frequency band, excellent skirt, ripple and isolation characteristics, and at the same time small in volume and weight.

Referring to FIG. 8, the interference suppression system filter unit 30 includes one or more interference suppression system filter modules (ISS FM) 31 and a compensation circuit 33.

Here, when two or more filters are connected in series, the skirt and isolation characteristics of two or more filter combinations are more than doubled when compared to one, but another important characteristic of the filter combination is insertion loss and ripple. The property is more than doubled.

Therefore, the present invention first combines a low noise amplifier (LNA) with one or more filters to compensate for insertion loss and to obtain the total gain required by the filter module.

Here, Insertion Loss is one of the important characteristics of the filter, which means that the signal loses power as it passes through the filter.If S21 is less than 0 dB in the pass band, all input power is not output. In other words, it means that a loss of power has occurred. In other words, as much as S21 falls from 0 dB, the insertion loss is referred to as dB.

In this case, the number of LNAs is determined by the gain characteristics required by the filter module, and the LNA is the first filter of the interference suppression system filter module (ISS FM: 31) to reduce the noise figure, which is also one of the important characteristics. It is preferable to mount at the front end, but it may be deleted.

The above-described interference suppression system filter module (ISS FM: 31) can be designed to be used in a high output mobile communication device having a skirt, adjacent channel leakage facilities and gains sufficiently, which is 100 watt or more, which is an interference noise outside the signal band. Signal) can be sufficiently suppressed.

Here, the ripple increases according to the number of BPFs. Accordingly, since the damage of the ripple characteristic occurs by a multiple of the number of the combined BPFs, the total ripple characteristic of the filter module is sufficiently compensated.

The BPF according to the present invention can use all kinds of filters, and depending on the implementation type, a concentrated element, a transmission line, a microstrip or a stripline, a ceramic, or Dielectric or waveguide, Surface Acoustic Wave (SAW), MEMS, LTCC, FBAR and the like may be used.

Here, the lumped element is a device which can be made by soldering lead or SMD L and C elements to the PCB, and in the case of several GHz or more, a microstrip or stripline that can be implemented in consideration of coupling, resonance, and multiple impedance connection is used. .

In addition, the ceramic or the dielectric is a structural filter using the resonance according to the wavelength, it is made by using a high dielectric dielectric ceramic to reduce the electrical wavelength of the signal, to implement a smaller filter.

In addition, the waveguide is a case of directly using the resonance phenomenon, there is a Cavity method using a metal block or a ceramic method to insert a dielectric, SAW is used in the filter of portable equipment, such as mobile communication terminal pursuing small size, light weight, thin do.

In addition, a compensation circuit 33 is provided to compensate for the ripple between the two interference suppression system filter modules (ISS FM: 31), where the ripple is the highest and lowest of the insertion loss in the signal passband. The difference is obtained by measuring S21, usually expressed in dB.

Therefore, in order to perform the above-described compensation, the compensation circuit 30 uses a band stop filter (BSF) as much as the band in which the ripple exists to compensate for the ripple.

In other words, by using the BSF, the ripple is prevented from passing by the existing frequency band, thereby compensating for the ripple.

Alternatively, a compensation filter 33 includes a directional filter, which is configured to separate and combine a transmission frequency band and a reception frequency band when the transmission line is a 2-wire type, and separates only the band where the ripple exists. And inhibit.

Then, the rest of the interference suppression system filter module (ISS FM: 31) is preferably further provided at the rear end of the compensation circuit 33, the configuration and operation of the remaining interference suppression system filter module (ISS FM: 31) Since it is the same as the interference suppression system filter module (ISS FM: 31) mentioned above, the description thereof will be omitted.

Through the above-described interference suppression system filter unit (ISS FU) 30, adjacent channel leakage equipment has been refined at least -80dB or more, and the signal amplified by the plurality of LNAs to 30dBm is a power amplifier 50 and an adaptive feedforward linearization circuit ( 70).

First, since the intermodulation distortion (IMD) component is included in the power amplifier 50 that is output from the interference suppression system filter unit 30 and is a nonlinear device, only the intermodulation distortion signal is removed from the reference signal + intermodulation distortion signal. To this end, the signal of the interference suppression system filter unit 30 is removed from the signal output from the power amplifier 50 so that only the intermodulation distortion signal remains as negative energy.

Then, when the output of the power amplifier 50 and the -energy intermodulation distortion (IMD) are added, the intermodulation distortion (IMD) component of the power amplifier 50 is summed in the second combiner 80. The distortion signal is completely removed, that is, a linear frequency signal can be radiated to the atmosphere through the antenna ANT.

Accordingly, the adaptive feedforward linearization circuit 70 detects an output signal including a distortion signal of the signal output from the power amplifier 50 and receives only the distortion signal by receiving the output signal of the interference suppression system filter module 30. The non-linearity of the frequency signal radiated to the antenna ANT can be completely eliminated by removing the original signal so that the original signal is left and increasing the distortion signal and subtracting it from the signal output from the power amplifier 50.

That is, the interference suppression system filter unit 30 primarily improves the characteristics of adjacent channel leakage equipment to increase the separation from other channel frequencies, and secondly, the power amplifier 50 in the adaptive feedforward linearization circuit 70. By completely removing the intermodulation distortion generated in the), it is made to maximize the efficiency due to the synergistic effect of the interference suppression system filter unit 30 and the adaptive feed forward linearization circuit 70.

At this time, the power amplifier 50 is designed to have a gain between 8dB and 20dB.

In addition, even if the power amplifier 50 amplifies the power in the nonlinear region, the interference suppression system filter unit 30 according to the present invention improves the characteristics of the adjacent channel leakage equipment, and in the adaptive feedforward linearization circuit 70 By canceling the intermodulation distortion signal in the form of amplification and subtraction, it is a feature of the present invention that the power, gain, and efficiency can be satisfied with a linear output.

Therefore, the present invention has a high efficiency and is configured so that the power of most input signals is not radiated to heat, minimizing the configuration of the heat dissipation device and the heat sink, thereby miniaturizing the mobile communication device, can reduce the waste of power And an adaptive feedforward linearization circuit is further added so that non-linear distortions that may occur at the output stage can be controlled to be eliminated before being radiated to the antenna.

6 is a view for explaining the concept of an adaptive feedforward linearization circuit according to the present invention. As shown in FIG. 6, the method of (a) and (b) have similar basic concepts, and any of them may be used.

Here, unlike the feedback, the feedforward is a concept of solving the distortion component at the output stage itself rather than extracting the distortion component and sending it to the input stage.

In (a), after extracting a part of the output signal from the first coupler, a part of the output signal mixed with intermodulation distortion (IMD) through the power amplifier (PA) is also extracted using the second coupler, the second coupler When the signal of the first coupler is subtracted from the signal extracted from, the fundamental frequency disappears and only the intermodulation distortion component remains in the − direction.

If the amplitude is amplified using an error amplifier (EA) and combined again using a combiner at the end of the output stage, only the intermodulation distortion is subtracted, so that the intermodulation distortion component is completely removed. .

Here, the reason why the time delay is required is to accurately match the time taken for the signal processing in the amplifier to the time taken by the signal extracted from the original signal, that is, correcting the time difference, and the extracted signal is the original signal. Because the power level is lower, the intermodulation distortion (-IMD) must be amplified and combined through the error amplifier (EA) to the original signal level to ensure that intermodulation distortion components are removed.

This method eliminates the intermodulation distortion generated at the output stage where the actual intermodulation distortion occurs, resulting in an excellent linearity increase, but because of the large output signal level, the configuration and volume are large. Expensive base station or the like is required for an expensive linearization method, which is widely used. The present invention also uses the above method.

In (b), the basic concept is similar to that of (a), but it is subtracted from the final combiner without converting the intermodulation distortion signal in the-direction.

That is, (a) is in the form of (original signal + intermodulation distortion) + (-intermodulation distortion), and (b) has the form of (original signal + intermodulation distortion)-(intermodulation distortion), and The basic concepts are similar, so you can use either one.

In addition, the concept of the adaptive feedforward linearization circuit is described in "RF MICROELECTRONICS" by B.RAZABI, Pretice Hall, NJ, 1998, Chapter 9, and a detailed description thereof will be omitted.

In addition, the announcement shows that an adaptive feedforward linearization circuit can increase the output efficiency by 25% for Class AB power amplifiers, all of which can be converted to digital signals.

In the present invention, the adaptive feedforward linearization circuit is used, but the interference suppression system filter unit is configured to maximize the adjacent channel leakage facilities to achieve the synergistic effect of efficiency and linearization at the output stage. It is not limited to what is demonstrated in this invention, You may use any.

Figure 7 illustrates in detail the adaptive feedforward linearization circuit according to the present invention. As shown in FIG. 7, the adaptive feedforward linearization circuit 70 includes a first coupler 71, a first time delayer 72, a second coupler 73, a first coupler 74, and an error amplifier. 75, a second time delay 76, and a second coupler 80.

Here, the first coupler 71 extracts a part of a signal of a high frequency signal from the adjacent channel leakage equipment output from the interference suppression system filter unit 30 and inputs it to the first time delay unit 72 because of the power. This is to match the output signal of the second coupler 73 which extracts a part of the output signal of the power amplifier 50 according to the driving time of the amplifier 50.

That is, the first coupler 74 has a time between the signal output directly through the first coupler 71 without passing through any amplifier and the signal passed through the amplifier via the power amplifier 50 and the second coupler 73. Because you have to fit.

Then, when (original signal)-(original signal + intermodulation distortion) is performed in the first combiner 74, only the intermodulation distortion of the-component remains, which removes the output signal of the power amplifier 50. Since extraction by the two coupler 73, the power level is low, thereby passing through an error amplifier (EA) 75 to amplify the amount of intermodulation distortion.

Here, since the second combiner 80 has to time the signal passed through the error amplifier 75 and the signal output from the power amplifier 50, the second combiner 80 is connected between the power amplifier 50 and the second combiner 80. And a time delay 76.

Therefore, by adding the intermodulation distortion of the-components in the output signal of the power amplifier 50, the intermodulation distortion is canceled out to maximize the linearization of the output signal and remove various interferences, noise, harmonics, intermodulation distortion, etc. A signal with a high adjacent channel leak facility will be radiated.

9 is a graph comparing signals input to a driving amplifier according to the present invention and a driving amplifier according to the prior art. As shown in Figure 9, (a) is a signal input to the drive amplifier in the prior art, (b) is a signal input to the drive amplifier according to the present invention.

(A) shows the shape and size of the full-band WIBRO signal, and shows an input signal input to the driving amplifier DA, which is a first amplified signal by the LNA.

(B) shows the shape and size of the full-band WIBRO signal, and shows an input signal input to the driving amplifier DA 10, which is a first amplified signal by the LNA.

10 is a graph illustrating a signal output from a driving amplifier according to the present invention. As shown in FIG. 10, since the output of the driving amplifier 10 according to the present invention is input to the interference suppression system filter unit 30 to compensate for the characteristics of the adjacent channel leakage facility, the characteristics of the adjacent channel leakage facility are Not so important, only the size of the output.

On the other hand, the driving amplifier DA according to the prior art should have at least -50 dB of adjacent channel leakage facilities and be separated from other frequency bands when all characteristics including adjacent channel leakage facilities are amplified through the last power amplifier PA. .

Accordingly, when looking at the adjacent channel leakage equipment (ACLR), it can be seen that the characteristics deteriorate from -32.364 dB to -20.460 dB in FIG. 9, which increases the gain of the driving amplifier 10 and improves the characteristics of the adjacent channel leakage equipment (ACLR). It is not considered, and even if it is not separated from other channels, the interference suppression system filter unit 30 will compensate for adjacent channel leakage equipment (ACLR) and refine it to be separated from other channels. ) Can only compensate for gain.

In addition, the magnitude of the signal passed through the driving amplifier 10 is 34.4 dBm, which is large enough to compensate for the loss of the signal (about 5 dB) generated while purifying the signal in the interference suppression system filter unit 30 of the next stage. to be.

Therefore, the driving amplifier 10 according to the present invention is input to the interference suppression system filter unit 30 to output a signal while compensating the gain of about 60dB to 70dB to correspond to the efficiency of the entire output stage.

11 is a graph comparing signals input to a power amplifier according to the present invention and a power amplifier according to the prior art. As shown in Figure 11, (a) is a signal input to the power amplifier (PA) according to the prior art, (b) is a power amplifier (PA) via the interference suppression system filter unit 30 according to the present invention , 50).

That is, (a) is a signal output from the drive amplifier (DA) because the interference suppression system filter unit 30 according to the present invention is not present, (b) is the drive amplifier 10 and the power amplifier 50 Since the interference suppression system filter unit 30 is included therebetween, it is an output signal passed through the interference suppression system filter unit 30.

In (A), the adjacent channel leakage equipment is -42.549dB, and (B) shows that the adjacent channel leakage equipment is -75.971dB.

That is, it can be seen that the interference suppression system filter unit 30 according to the present invention has been refined by about -75.971 dB to increase the signal separation from other channels.

In addition, (b), the size of the signal output from the interference suppression system filter unit 30 is 31dBm, the adjacent channel leakage equipment, as mentioned above, the noise removal and separation with other frequency bands of about -75.971dB It can be seen that a signal having excellent characteristics is outputted due to a high value.

12 is a graph comparing signals output from a power amplifier according to the present invention and a power amplifier according to the prior art. As shown in FIG. 12, (a) is an output signal of the power amplifier PA according to the prior art, and (b) is an output signal of the power amplifier 50 according to the present invention.

(A), in the form of a full-band WIBRO output signal of 43.38 dBm (20 W) size, the efficiency of the power amplifier (PA) in this case is approximately 50%, but the adjacent channel of the signal is -29.205 dB. As a result, it can be seen that it does not satisfy -37dB, the pass characteristic specified in the WIBRO specification.

The reason is that even if the characteristics of the signal input to the power amplifier PA are excellent, since the gain of the power amplifier PA is 30 dB to 50 dB, the signal outside the frequency is also amplified to 30 dB to 50 dB with the signal within the frequency.

Therefore, when the mobile communication device is provided with an output terminal according to the prior art, the efficiency is significantly lowered due to the nonlinearity of the power amplifier and the characteristics of the adjacent channel leakage facility.

On the other hand, in (B), it is 43.08dBm (20W) full-band WIBRO output signal, and the characteristics of adjacent channel leakage equipment is -38.414dB, satisfying WIBRO specification and increasing power efficiency by 50%.

That is, according to the present invention, the interference suppression system filter unit 30 improves the characteristics of the adjacent channel leakage equipment, so that the separation can be increased so that there is no noise and interference with other bands, and the adjacent channel characteristic ratio in the driving amplifier 10 is improved. Since the gain can be increased without taking into consideration, the efficiency of the power amplifier 50 can be the same as that of the linear region even if the power amplifier 50 operates in the nonlinear region, thereby increasing the efficiency of the power to the output power supplied to the power amplifier 50. In addition, the power loss is minimized to increase power efficiency, and at the same time, the size and volume of the mobile communication device can be minimized by eliminating and minimizing the heat dissipation device and the heat sink.

Input signal (dBm) Drive amplifier
Output signal (dBm) Power amplifier
Output signal (W) efficiency(%) Adjacent channel leak facilities (dBc) EVM (%) -32.2 26.1 10 28.12 -41.5 2.6 -31.0 27.5 15 40.58 -38.7 4.13 -28.8 28.8 20 49.60 -38.4 7.1

Input signal (dBm) Drive amplifier
Output signal (dBm) Power amplifier
Output signal (W) efficiency(%) Adjacent channel leak facilities (dBc) EVM (%) -33.2 24.2 10 30.27 -39 2.1 -31.9 26.4 15 42.86 -38.4 3.7 -30.6 27.3 20 53.71 -37.1 5.55

Table 1 and Table 2 show measured values when the output terminal according to the present invention is applied to the mobile communication equipment of the full-band WIBRO.

The efficiency of the output stage increases as the output increases, and when the output of the power amplifier used in the experiment is 20W, the efficiency is about 50%. In the case of WCDMA, the efficiency is approximately 20W. It is estimated to be 27%, and the ripple effect of the result is expected to be large.

Here, Table 1 and Table 2 are both measured values of WIBRO, and experiments using two different types of output stages, but show similar efficiency.

On the other hand, when the output stage according to the present invention is applied to the WCDMA is at least 30% or more, and in the case of WIBRO higher efficiency can be obtained because of the switching process between the receiver and the transmitter of WIBRO or WIMAX to be.

13 is a schematic block diagram of a WIBRO repeater with an output stage according to the present invention. As shown in Fig. 13, first, data received from one of two antennas is amplified by a low noise amplifier (LNA).

The reason is that since the power received at the RF receiver has a very low power level due to the effects of attenuation and noise, the signal is already received including a lot of noise from the outside, so minimizing the noise is a priority.

Then, when the gain taking into account the insertion loss of the interference suppression system filter unit 30 and the like through the drive amplifier 10 according to the present invention, that is, insertion loss of the interference suppression system filter unit 30 occurs, the driving amplifier ( The signal is amplified in consideration of the gain for compensation in 10) because the interference suppression system filter unit 30 purifies characteristics of adjacent channel leakage facilities and the like.

Therefore, the signal amplified with sufficient gain from the driving amplifier 10 is input to the interference suppression system filter unit 30 to increase the separation with other frequencies and noises and to improve the characteristics of adjacent channel leakage facilities.

In addition, the power amplifier 50 does not need to operate in the nonlinear region to give a large gain as in the prior art, and outputs a signal with high efficiency while having the same effect as operating in the linear region, and at the same time, frequency signals in the nonlinear region. Even if it comes out, it is completely removed from the adaptive feed forward linearization circuit 70, it is made to maximize both the gain, power, efficiency by satisfying all the characteristics of the adjacent channel leakage and linearity.

That is, even if the power amplifier 50 operates primarily in the nonlinear region, the interference suppression system filter module 30 according to the present invention improves the adjacent channel leakage facility characteristic, which is the degree of separation from other frequency bands, and also increases the gain of the driving amplifier. This allows the gain of the power amplifier to be adjusted below 20 dB, greatly reducing the burden, resulting in the same efficiency as operating in the linear region even when the power amplifier 50 operates in the non-linear region. By canceling the original signal, the intermodulation distortion signal is removed at the final stage and radiated to the air through the antenna, so that the output signal can be linearized, increased in efficiency, and output at maximum power.

Therefore, since the present invention increases the efficiency of the power amplifier 50 as a result, it is possible to reduce the rate of loss of input power to heat, thereby reducing the power consumption, and to minimize the configuration of the heat dissipation device and the heat sink. The volume and weight of the mobile communication device equipped with the output stage of the present invention can be miniaturized, and the characteristics of the adjacent channel equipment meet the WIBRO standard, so that it is possible to receive purified and clean signals, and has a linear frequency. The signal can be output for maximum efficiency.

In addition, since the signal received by the antenna on the opposite side is processed in the same manner as the above-mentioned process will be omitted.

Finally, the output terminal according to the present invention may be applied to all output terminals including the driving amplifier and the power amplifier at the output terminal of the mobile communication device.

14 is a view showing a filter of the interference suppression filter unit of the output stage according to the present invention. As shown in FIG. 14, a filter applied to the present invention is generated as shown in (b).

First, as shown in (a), one filter is formed by combining a plurality of resonators in series, and all five resonators are formed as DR cavity resonators, and in (b), one resonator is made of metal. It can be seen that the cavity is a cavity cavity (Metal Cavity Resonator), the remaining four resonators are formed of a DR cavity cavity (DR Cavity Resonator).

Here, in the case of (b), the spurious characteristic can be greatly improved without significantly damaging the insertion loss, but the spurious characteristic is unnecessary harmonics and harmonics generated in addition to the frequency desired by the radio transmitter. Refers to the signal component of.

In addition, the unnecessary harmonic and low-harmonic signal components are copied into the space, called spurious radiation or unnecessary radiation, and they are strictly limited to a certain limit or less because they interfere with other communication.

Therefore, a metal cavity resonator made of metal both outside and inside of the resonator and a DR cavity resonator made of a metal outside and inside of the dielectric are connected in series to improve spurious characteristics, and a compensation circuit does not need to be connected in series. Ripple is adjustable below 2dB.

However, when strict ripple characteristics are required, it is desirable to connect a compensation circuit.

In the above described exemplary embodiments of the present invention by way of example, the scope of the present invention is not limited only to this specific embodiment, and those skilled in the art within the scope of the claims of the present invention Changes may be made as appropriate.

1 is a graph for explaining the concept of adjacent channel leak facilities.

2 is a schematic illustration of the output stages of a base station and repeater according to the prior art;

3 is a graph illustrating the output spectral density of a single channel output of a communication device according to the prior art.

Figure 4 is a block diagram showing a feedforward linearization circuit of a mobile communication system according to the prior art.

5 is a diagram illustrating an output terminal of a mobile communication device to which an adaptive feedforward linearization circuit and an interference suppression system filter unit according to the present invention are applied.

6 is a conceptual diagram illustrating a concept of an adaptive feedforward linearization circuit according to the present invention.

Figure 7 illustrates in detail the adaptive feedforward linearization circuit according to the present invention.

8 is a detailed view of an interference suppression system filter unit according to the present invention;

9 is a graph comparing signals input to a driving amplifier according to the present invention and a driving amplifier according to the prior art.

10 is a graph showing a signal output from a drive amplifier according to the present invention.

11 is a graph comparing signals input to a power amplifier according to the present invention and a power amplifier according to the prior art.

12 is a graph comparing signals output from a power amplifier according to the present invention and a power amplifier according to the prior art.

Figure 13 is a schematic block diagram of a WIBRO repeater with an output stage in accordance with the present invention.

14 is a view showing a filter of the interference suppression filter unit of the output stage according to the present invention.

      <Brief description of reference numerals for the main parts of the drawings>

10: drive amplifier 30: interference suppression filter unit

31: interference suppression filter module 31a: LNA

31b: band pass filter 33: compensation circuit

40: combiner 50: power amplifier

70: first coupler 72: first time delayer

73: second coupler 74: first coupler

75: error amplifier 76: second time delay

80: second coupler

Claims (15)

A driving amplifier which receives an RF analog frequency signal received through an antenna or a plurality of antennas and converts the RF analog frequency signal into a frequency signal having a predetermined gain and power; Passing or stopping the frequency signal input through the driving amplifier, increasing the adjacent channel leakage equipment (ACLR) by compensating and removing interference signals and ripples except the frequency band passed or blocked, and a constant gain and An interference suppression system filter unit for converting the power into a frequency signal; A power amplifier for amplifying the power of the frequency signal output from the interference suppression system filter unit, converting the signal into an RF analog frequency signal having a predetermined power and radiating it through an antenna; A frequency signal output from the interference suppression system filter unit and a power amplifier is input, and an output signal of the power amplifier is removed from the output signal of the interference suppression system filter unit to amplify only an intermodulation distortion (IMD), and the power amplifier Adaptive feedforward linearization circuit to linearize the output signal of the power amplifier by removing the amplified intermodulation distortion (IMD) from the signal output from An output terminal of a mobile communication device to which an adaptive feedforward linearization circuit and an interference suppression system filter unit are applied. The method according to claim 1, The power amplifier is connected between the interference suppression system filter unit and the power amplifier, the adaptive feedforward linearization circuit and the interference suppression system filter unit, characterized in that connected in parallel with the interference suppression system filter unit. Output stage. The method according to claim 1, The adaptive feedforward linearization circuit A first coupler for extracting a part of an output signal of the interference suppression system filter unit; A first time delayer for delaying an output signal of the first coupler for a predetermined time; A second coupler for extracting a part of a frequency signal including intermodulation distortion (IMD) from the power amplifier; A first combiner for subtracting an output signal of the second coupler from an output signal passing through the first delayer and outputting the intermodulation distortion (IMD) in a negative direction; An error amplifier for amplifying the amount of intermodulation distortion output from the first combiner; A second time delay delaying the output signal of the power amplifier for a predetermined time; A second combiner for summing the powers of the second time delay and error amplifier An output terminal of a mobile communication device to which the adaptive feedforward linearization circuit and the interference suppression system filter unit are applied. The method according to claim 1, The gain of the power amplifier is less than 20dB within a range capable of producing a linear output in a region having linearity and / or a nonlinearity because the adjacent channel leakage facility of the signal output from the interference suppression system filter unit is high. An output terminal of a mobile communication device to which an adaptive feedforward linearization circuit and an interference suppression system filter unit are applied. The method according to claim 4, The gain of the driving amplifier has a gain obtained by subtracting the sum of the gain of the power amplifier and the gain or loss of the interference suppression system filter unit from the total gain of the output stage, the adaptive feedforward linearization circuit and the interference suppression system. Output terminal of mobile communication device to which filter unit is applied. The method according to claim 1, The interference suppression system filter unit At least one interference suppression system filter module configured to pass and stop a frequency signal of a predetermined band and amplify the passed frequency signal; Compensation circuit for stopping and compensating the ripple band generated in the filter module that compensated the interference signal An output terminal of a mobile communication device to which the adaptive feedforward linearization circuit and the interference suppression system filter unit are applied. The method according to claim 6, The one or more interference suppression system filter modules; Two or more series-connected filters having the same characteristics to pass and stop a frequency band signal; LNA provided to compensate for insertion loss caused by the stop band in the filter An output terminal of a mobile communication device to which the adaptive feedforward linearization circuit and the interference suppression system filter unit are applied. The method of claim 7, And the filter is formed of any one of a dielectric or metal cavity or a DR-metal cavity or stripline. The output stage of the mobile communication device to which the adaptive feedforward linearization circuit and the interference suppression system filter unit are applied. The method of claim 7, And said filter comprises a combination of a dielectric or metal cavity or a dielectric resonance-metal cavity or stripline. An output stage of a mobile communication device to which an adaptive feedforward linearization circuit and an interference suppression system filter unit are applied. The method of claim 7, The LNA has a gain according to the insertion loss and compensates the insertion loss generated in the filter, and is connected to the filter in series, and the output terminal of the mobile communication device to which the adaptive feedforward linearization circuit and the interference suppression system filter unit are applied. . The method of claim 7, The compensation circuit is an adaptive feedforward linearization circuit and interference suppression, characterized in that for the compensation of the ripple generated in the interference suppression system filter module to suppress the amplitude as much as the ripple magnitude in the frequency band where the ripple occurs Output stage of mobile communication device with system filter unit. The method of claim 11, The filter is an output stage of an adaptive feedforward linearization circuit and an interference suppression system filter unit to which an adaptive feedforward linearization circuit (BSF) prevents the amplitude of the ripple-generated frequency band and the amplitude of the ripple. . The method of claim 11, The filter is a directional filter for blocking the amplitude of the ripple is generated by the frequency band and the magnitude of the ripple (Directional Filter) characterized in that the output stage of the mobile communication device to which the adaptive feedforward linearization circuit and the interference suppression system filter unit is applied. . The method according to claim 1, The power amplifier is an output terminal of an adaptive feedforward linearization circuit and interference suppression system filter unit is applied, characterized in that the power transistor (Power Transistor) consisting of a MOSFET or gallium nitride (GaN). The method according to claim 1, The output terminal of the mobile communication device Low noise amplifier to amplify the RF signal received by the antenna or a plurality of antennas in front of the drive amplifier An output terminal of a mobile communication device to which the adaptive feedforward linearization circuit and the interference suppression system filter unit are further provided.

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