KR100396777B1 - Output power controlling circuit - Google Patents

Abstract

The present invention relates to a transmission power control circuit, comprising: a filter unit for amplifying a signal output with a predetermined gain from a frequency upconverter by a high power amplifier, and filtering only a signal of one frequency band from the amplified signal, and a final output through an antenna A frequency up-converter control circuit including a control circuit unit for controlling a transmission gain value of the frequency up-converter according to a level of a signal, wherein the frequency up-converter has a frequency detection function for detecting a signal finally outputted through an antenna; The detected output signal is output to the control circuit section to generate a transmission gain value, and the gain control voltage output from the transmission gain controller inside the frequency upconverter and the gain control voltage output from the control circuit section are selectively selected. Transmit power is controlled by input to attenuator ATT By maintaining the desired transmission output at the base station, the same function can be performed with the minimum components in adjusting the desired output, and the base station system can be flexibly operated during the FA expansion of the base station. It is effective.

Description

Transmission power control circuit {OUTPUT POWER CONTROLLING CIRCUIT}

The present invention relates to a frequency up-converter, and in particular, to maintain the desired transmission output at the base station constant and to perform the same function with a minimum configuration in adjusting the desired output, the base station system during the expansion of the base station FA The present invention relates to a transmission power control circuit that can flexibly operate.

In general, the frequency up-converter compensates for the change in power according to the number of traffics and gain of the baseband signal, so that the output to the input has a constant gain, and the output is constant. It has a role to maintain.

1 is a block diagram showing the structure of a conventional transmission power control circuit, as shown therein, a frequency up-converter 1 which receives an intermediate frequency signal, adjusts gain, and outputs it; A high power amplifier (HPA) (2) for power amplifying the signal output from the frequency up-converter (1) through an antenna; A front end filter (F.E.F) 3 for filtering and outputting only one frequency band signal from the high power amplified signal; An output signal detector 4 for detecting a final output signal of the base station; And a control circuit section 5 for outputting a control signal for local frequency adjustment and a transmission gain value TX_RF_GAIN by the signal output from the output signal detection section 4.

At this time, in the frequency up-converter 1, a part of the intermediate frequency signal input is divided into a signal and input to the input signal detector 1l. Accordingly, the input signal detector 1l amplifies the signal by a predetermined level and thus a transmission gain controller. (TX AGC CIRCUIT) 1m, and the output signal detector 1n detects the final output signal of the frequency up-converter 1 through the coupler 1h and transmits it to the TX AGC CIRCUIT 1m. Is authorized.

Accordingly, the transmission gain controller 1m receives the transmission gain value TX_RF_GAIN output from the control circuit 5 and the voltage output from the input signal detector 11 and the output signal detector 1n, and the attenuator ATT. The gain control voltage TX_AGC VOLTAGE is output to control (1e, 1f) so that an appropriate gain can be obtained.

Here, the PAD 1a, which has not been described, means a fixed attenuator, and the isolator 1i prevents a high level voltage from being inputted back to the frequency up-converter 1 in the high power amplifier HPA. And outputs in only one direction.

In addition, the mixing unit MIX1 mixes the intermediate frequency signal TX_IF inputted to the frequency up-converter 1 with the local frequency LOCAL1 filtered through the band filter 1k to convert to the high frequency TX_RF.

Next, the control circuit section 5 includes: an AD conversion section 5a for AD converting the signal output from the output signal detecting section 4; A control circuit (5b) for monitoring the AD converted signal and outputting a control signal (LO FREQ control signal) and a transmission gain value (TX_RF_GAIN) for controlling the local frequency accordingly; And a die conversion unit 5c for performing a die conversion of the transmission gain value TX_RF_GAIN.

Hereinafter, the operation and operation of the device configured as described above are as follows.

First, the intermediate frequency signal TX_IF input to the frequency upconverter 1 is converted into a high frequency signal TX_RF having an arbitrary level and gain, and is outputted. The high frequency signal TX_RF is a high power amplifier HPA 2. Power is amplified.

Next, unwanted frequency components of the high power amplified signal are removed by the F.E.F (3), and only signals of a predetermined frequency band are filtered and copied through the transmit antenna ANT.

In this process, the output signal detector 4 detects a signal output to the transmitting antenna ANT through the coupling terminal of the F.E.F (3) in order to monitor the transmission output and control it to a desired level.

Next, in order to facilitate processing of the detected output signal, the local frequency LOCAL2 is mixed and converted into an intermediate frequency, and the signal in which the local frequency LOCAL2 is mixed is desired through a SAW Filter 4c. After filtering the non-frequency components, the level of the signal is detected and output through the output detector 4e.

The signal level detected by the output detector 4e is input to the control circuit section 5 and converted into a digital signal, and the control table 5b stores the digitally converted signal level and the power table stored in the ROM 5d. By comparing the voltage levels, it is determined whether it is the desired output level and the transmission gain value TX_RF_GAIN is adjusted to be the desired output level.

Next, the transmit gain value TX_RF_GAIN is subjected to the die conversion by the die converter 5c and input to the transmit gain controller 1m of the frequency up converter 1.

Accordingly, the frequency up-converter 1 receiving the transmission gain value TX_RF_GAIN converts the control voltage of the voltage controlled attenuator ATT to adjust the output from the transmitting antenna to a desired value.

The control circuit 5b also controls the oscillation frequencies of the local frequency oscillators 1j and 4f of the frequency up-converter 1 and the output signal detector 4.

In other words, the local frequency LOCAL2 existing in the output signal detector 4 is converted into a desired frequency (FA) to transmit alpha (A), beta (B), and gamma (G) paths. By monitoring the output and comparing it with the power table stored in the ROM 5d of the control circuit section 5, if it is not the desired output, the control circuit section 5 changes the transmission gain value TX_RF-GAIN signal. In the meantime, the change of the transmission gain value TX_RF-GAIN is repeated until it is equal to the desired output stored in the ROM 5d.

However, in the conventional technology, a large number of components are used to realize the performance, and in particular, the output signal detector 5 has a similar functional part used for gain adjustment (AGC) in the frequency up-converter 1. It is.

As such, since there are many parts to be used, the error due to the characteristic difference of each part may be large, and since the output signal detection unit 4 is implemented as a separate unit, the capacity to perform the monitoring function is determined to be 2FA / 3 sectors. Therefore, it is difficult to flexibly operate due to the expansion of frequency allocation (FA).

In addition, the configuration of the output signal detector 4 is implemented with three paths A, B, and G. In order to monitor a specific frequency allocation FA, a separate control is performed to control the local frequency LOCAL2 according to the FA. The PLL block has to be implemented, and only 1FA power monitoring is possible, and there is a problem in that it is not possible to simultaneously monitor the transmission power of 2FA / 3 sectors.

Therefore, the present invention has been created to solve the above-mentioned conventional problems, it is possible to perform the same function with a minimum configuration in maintaining the desired transmission output at the base station constant and adjusting the desired output, It is an object of the present invention to provide a transmission power control circuit that allows the base station system to be flexibly operated when the base station FA is expanded.

1 is a block diagram showing the configuration of a conventional transmission power control circuit.

Figure 2 is a block diagram showing the configuration of a transmission power control circuit according to the present invention.

Figure 3 is a block diagram showing the configuration of a conventional multiple transmit power control circuit for comparing and explaining the operation of the conventional and the present invention.

Figure 4 is a block diagram showing the configuration of a multiple transmit power control circuit according to the present invention for comparing and explaining the operation of the prior art and the present invention.

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

10: frequency upconverter 20: high power amplifier

30: F.E.F 40: Control circuit part

In order to achieve the above object, the present invention provides a filter unit for amplifying a signal output from the frequency up-converter 10 with a predetermined gain by the high power amplifier 20 and filtering only signals of one frequency band from the amplified signal ( 30), and a control circuit unit 40 for controlling the transmission gain value of the frequency up-converter 10 according to the level of the signal finally output through the antenna (ANT), the frequency up-converter control circuit, the frequency The up-converter 10 may generate a transmission gain value by outputting a frequency detection function for detecting a signal finally output through the antenna ANT and the detected output signal to the control circuit unit 40, and The attenuator ATT selectively outputs a transmission gain value output from the control circuit unit 40 and a gain control voltage output from the transmission gain controller 10n inside the frequency up-converter 10. To ensure that the input is characterized in that is configured to control the transmission power.

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

Figure 2 is a block diagram showing the configuration of a transmission power control circuit according to the present invention, a difference from the conventional transmission power control circuit will be described.

First, in the present invention, the directional coupler existing in the conventional frequency upconverter is removed, and the gain control (AGC) loop is enlarged by using the coupling port of the F.E.F 30.

Next, the output signal detector, which was present separately from the output signal detector implemented in the conventional frequency upconverter, further includes a frequency mixer MIX2 and a filter SAW in the frequency upconverter, The local frequency oscillator (LOCAL1) can be used jointly to remove the external output signal detector (4).

That is, the local frequency signal LOCAL1 used inside the frequency upconverter is branched into the directional divider (2WAY) 10k, and some of the frequencies for converting the intermediate frequency signal inside the frequency upconverter into a high frequency signal are conventionally used. It is applied to the mixer MIX1, and another part is input to the frequency mixer MIX2 newly added by the present invention.

In other words, the output signal detector 10q, which was separately present in the outside, is included in the frequency upconverter.

In addition, a switching unit SW1 for selectively inputting the gain control voltage AGC CONTROL VOLTAGE and the transmission gain value TX_RF_GAIN to the voltage control attenuators 10e and 10f is further provided.

As described above, the frequency upconverter according to the present invention uses an internal transmission path (TX_IF to ANT output). The gain control (AGC) function and the desired frequency band (FA) and the power of a specific sector can be monitored simultaneously, and the desired power can be adjusted.

Next, the operation of the conventional circuit shown in FIG. 1 and the expansion of multiple FAs (2FA / 3 sectors) in the circuit of the present invention shown in FIG. 2 will be compared.

First, in the conventional control circuit shown in FIG. 1, the local frequency LOCAL1 generated by the local frequency control signal LO FREQ control signal 1 is mixed with the intermediate frequency input signal TX IF to obtain the high frequency signal TX RF ( Up-converted to FA1).

Next, when the up-converted high frequency signal (TX RF) is applied to 2FA / 3 sectors as shown in FIGS. 3 and 4, FA1-A, FA1-B, FA1-G and It is output through six paths of FA2-A, FA2-B and FA2-G.

Then, the combiner combines the signals of the same sectors, and combines three paths such as (FA1-A, FA2-A), (FA-1B, FA2-B), and (FA1-G, FA2-G). After configuration, amplify through each path amplifier (LPA-A, B, C), remove unwanted frequency components through each filter (FEF-A, FEF-B, FEF-G) and then each antenna (ANT -A, ANT-B, ANT-G).

In this case, the signal coupled through each of the filters (FEF-A, FEF-B, FEF-G) is a signal including FA1 and FA2 together, for example, a coupling distributed in two directions after coupling. The signal A or B, C is fed back to UPC F1-A (or B, C) and UPC F2-A (or B, C).

Accordingly, when the feedback signal is mixed with the local frequency signal LOCAL1 in the frequency mixer MIX2 of the frequency upconverter, in the case of a signal fed back to the UPC FA1-A, FA1- (UPC FA1-A LOCAL1), Down-conversion to the FA2- (UPC FA1-A LOCAL1) signal, and passing through a filter (SAW2) 10p removes unwanted FA components.

E.g,

TX IF = 160 MHz,

(UPC FA1-A LOCAL1) = 1700 MHz,

(UPC FA2-A LOCAL1) = 1750 MHz,

FA1 = 160 + 1700 = 1860 MHz,

FA2 = 160 + 1705 = 1865 MHz,

FA1- (UPC FA1-A LOCAL) = 1860-1700 = 160 MHz,

FA2- (UPC FA1-A LOCAL1) = 1865-1700 = 165 MHz,

FA2- (UPC FA2-A LOCAL) = 1865-1705 = 160 MHz,

FA1- (UPC FA2-A LOCAL1) = 1860-1705 = 155 MHz,

By using the filters SAW1 and 10c used in the intermediate frequency input signal TX IF of the frequency up-converter 10 as described above, unwanted frequency components are removed from each FA and sector, and the desired FA and sector Power is detected by the output signal detector 10o.

As a result, a part of the detected signal (analog signal) is output to the transmission gain controller 10n, and another part of the signal is input to the control circuit unit 40 and converted into a digital signal. Compare with the transmission output table stored in the base station.

That is, the control circuit unit 40 checks how much the converted power of the AD is smaller than a predetermined value, and controls the switching unit (SW1) 10l to prevent malfunction due to the overload of the LPA or HPA. The transmission gain value TX_RF_GAIN is input to the attenuation voltages of the attenuators 10e and 10f.

For reference, in the gain control off mode (AGC OFF MODE), an alarm signal indicating an abnormal state of the transmission power is output, and in the gain control on mode (AGC ON MODE), a signal fed back is very small or an output signal is output. When the detector 10o malfunctions and outputs a low voltage to the transmission gain controller 10n, the maximum power of the up converter is output by changing the gain control voltage by recognizing the transmission power of the base station and overloading the HPA or LPA. .

If the transmission power value converted by the control circuit unit 40 is greater than a predetermined value, the control circuit 40b outputs the gain control voltage output from the transmission gain controller 10n to the voltage control attenuators 10e and 10f. The switching unit 10l is controlled to input (AGC CONTROL VOlTAGE).

That is, the transmission gain value TX_RF_GAIN is adjusted until the transmission power value is the same as compared with the value stored in the ROM 40d of the control circuit unit 40 to determine whether the transmission power value is required by the control circuit.

On the other hand, the transmission gain control section 10n changes the gain control voltage AGC CONTROL VOLTAGE to keep the gain between the transmission paths TX_IF to F.E.F constant, regardless of the change in the transmission gain value TX_RF_GAIN.

In the multi-FA structure as described above, the frequency upconverter 10 itself of the corresponding FA and the corresponding sector stores the power table of the corresponding FA and the corresponding sector, and monitors the current transmission power in each frequency upconverter to real time the upper control unit. In this case, a separate operation can be performed to control the transmission power, thereby preventing the effort for a new application of the output signal detector during FA extension.

As described above, the transmission power control circuit of the present invention maintains a desired transmission output at the base station and also performs the same function with the minimum components in adjusting the desired output. In this way, the base station system can be flexibly operated.

In addition, the present invention is to remove the output signal detection unit provided separately, and to obtain the same output characteristics using the output signal detection unit inside the frequency up-converter, it is possible to reduce the cost and size of the base station and multiple base stations When the FA is supported to be added, it is possible to reduce the effort for setting up the output signal detector and to enable flexible operation.

In addition, the present invention compensates the gain change of the high power amplifier (HPA) from the intermediate frequency processing stage of the frequency upconverter to the filter unit (FEF) or the loss caused by the cable to transmit a constant base station without changing the transmission gain value Tx_RF_GAIN. It can get the output and prevent the malfunction of LPA or HPA due to abnormal overpower of frequency upconverter.

In addition, since the present invention does not include a separate output signal detector unlike the prior art, it is not necessary to apply a separate local frequency (LOCAL2) to obtain a desired FA when monitoring power of multiple FAs, and all FAs and sectors in real time. There is an effect to enable the control of.

Claims (4)

A filter unit for amplifying a signal output from the frequency upconverter with a predetermined gain by a high power amplifier, and filtering only a signal of one frequency band from the amplified signal, and according to the level of the signal finally outputted through the antenna. A transmission power control circuit comprising a control circuit section for controlling a transmission gain value, A second mixer (MIX2) for receiving an output signal transmitted through an antenna and converting a local frequency (LOCAL1) generated in the frequency up converter into an intermediate frequency signal for detecting transmission power; A first mixer MIX1 for converting the intermediate frequency signal inputted to the frequency up-converter into a high frequency signal; A directional divider for jointly applying a local frequency to the first and second mixers; A switching unit for selectively applying a transmission gain value output from the control circuit unit by the control of the control circuit unit or a gain control voltage output from the transmission gain controller inside the upconverter to the attenuator; A SAW filter for receiving and filtering the output of the second mixer; And an output signal detector for detecting the transmission power by the output signal of the filter and outputting the transmission power to the transmission gain controller or the control circuit unit. delete delete delete