KR20060030802A - Apparatus for power control using current sampling - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a power control device using current sampling.

2. The technical problem to be solved by the invention

The present invention provides power control using current sampling for controlling transmission power by using a voltage level obtained by sampling and converting a current consumed by the power amplifier, rather than directly detecting a radio frequency signal transmitted by the power amplifier. The purpose is to provide a device.

3. Summary of Solution to Invention

The present invention provides a power control apparatus using current sampling, comprising: current sampling means for obtaining a voltage by sampling a current applied from an external power supply means to an external power amplifying means; Level adjusting means for adjusting a voltage level received from the current sampling means; Differential amplifying means for differentially amplifying the voltage level received from the level adjusting means; Operation control means for controlling the operation of said level adjusting means and said differential amplifying means in accordance with an operation control signal; Filtering means for removing noise of the voltage received from the differential amplifying means; Conversion means for converting the voltage filtered by the filtering means into a digital signal; And control means for transmitting an operation control signal to the operation control means and controlling the transmission power of the power amplifying means according to the digital signal received from the conversion means.

4. Important uses of the invention

The present invention is used in a wireless communication terminal.

Current Sampling, Power Amplifier, Power Control, Wireless Communication Terminal

Description

Power control device using current sampling {Apparatus for power control using current sampling}             

1 is a configuration diagram of an embodiment of a conventional power control device;

2 is a block diagram of an embodiment of a power control apparatus using current sampling according to the present invention;

3 is a circuit diagram of an embodiment of a power control apparatus using current sampling according to the present invention.

* Explanation of symbols for the main parts of the drawings

21: power amplifier 22: current sampling unit

23: level adjusting unit 24: differential amplifier

25 peak detector 26 filter

27: analog / digital conversion unit 28: operation control unit

29: control unit

The present invention relates to a power control apparatus using current sampling. More particularly, the present invention relates to a power control apparatus using a voltage level obtained by sampling and converting a current consumed by the power amplifier instead of directly detecting a radio frequency signal transmitted by the power amplifier. The present invention relates to a power control apparatus using current sampling for controlling transmission power.

In the present invention, a wireless communication terminal is a mobile communication terminal, a personal digital communication terminal (PCS), a personal digital terminal (PDA), a smart phone, a next generation mobile communication terminal (IMT-2000), wireless communication while being carried by an individual such as a wireless LAN terminal. Say this is possible terminal.

In general, the control unit MSM of the wireless communication terminal may calculate power in advance to know the magnitude of power of a signal currently being transmitted and received, and may also know a threshold value of the transmission power.

At this time, the transmit power is adjusted to the level of a PDM (Pulse Density Modulation, PDM) signal TX_AGC_ADJ input to the power amplifier PAM.

The transmission power control method using the same is clearly implemented in a Qualcomm source of a code division multiple access (CDMA) wireless communication terminal.

Here, the wireless communication terminal can control the transmission power by configuring power in advance and configuring the PDM signal level and the magnitude of the power transmitted when the PDM signal is input.

However, the conventional transmission power control method compensates for the temperature because the power varies according to the temperature change even if the transmission is performed in the same PDM. However, since the power change value according to the temperature change is different for each channel or each wireless communication terminal, it is difficult to implement accurate power control with a Qualcomm source to which the same temperature compensation value is always applied.

Therefore, a high power detector (HDET) circuit is applied for power control. The HDET circuit is a circuit for converting power to a voltage level, and the control unit MSM does not output power any longer when the HDET value measured using the HDET circuit is equal to or greater than the 'HDET value measured at maximum power'. To prevent it. Looking in detail with reference to Figure 1 as follows.

1 is a configuration of an embodiment of a conventional power control device.

As shown in FIG. 1, the conventional power control apparatus includes a power amplifier 11 for amplifying a transmission signal, an antenna 12 for transmitting a signal output from the power amplifier 11, and the power amplification. Coupler 13 for extracting power from the transmission path (Tx Path) transmitted from the unit 11 to the antenna 12, a peak detector for converting the power extracted by the coupler 13 into a voltage of the direct current type ( 14), a filter 15 for removing noise of the voltage converted by the peak detector 14, an analog / digital converter 16 for converting the voltage output from the filter 15 into a digital signal, and the And a controller 17 for controlling the transmission power of the power amplifier 11 according to the digital signal received from the analog / digital converter 16.

That is, in the conventional power control apparatus, the coupler 13 is inserted into the transmission path (Tx Path) to extract power attenuated by tens of dBm, and then the extracted power is extracted from the peak detector 14 and the filter. The noise is attenuated by the DC voltage through 15, and the analog / digital converter 16 converts the voltage into a digital signal and transmits the voltage to the controller 17.

Accordingly, the conventional power control device generates power loss of about 0.2 to 0.7 decibels (dB) in the coupler 13, which adversely affects transmission performance. In addition, there is a possibility that the RF matching point is misaligned because perfect coupling is not performed.

In the conventional power control apparatus, the transmission (Tx) waveform is changed when the radio environment is changed in the code division multiple access 2000 1x (CDMA 2000 1x) network. Even if one signal is the same value, there is a problem that the actual power size may be different.

The present invention has been proposed to solve the above problems, and does not directly detect radio frequency signals transmitted by the power amplifier, but controls transmission power by using a voltage level obtained by sampling and converting current consumed by the power amplifier. It is an object of the present invention to provide a power control apparatus using current sampling.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. In addition, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a power control apparatus using current sampling, comprising: current sampling means for obtaining a voltage by sampling a current applied from an external power supply means to an external power amplifying means; Level adjusting means for adjusting a voltage level received from the current sampling means; Differential amplifying means for differentially amplifying the voltage level received from the level adjusting means; Operation control means for controlling the operation of said level adjusting means and said differential amplifying means in accordance with an operation control signal; Filtering means for removing noise of the voltage received from the differential amplifying means; Conversion means for converting the voltage filtered by the filtering means into a digital signal; And control means for transmitting an operation control signal to the operation control means and controlling the transmission power of the power amplifying means according to the digital signal received from the conversion means.

The present invention further includes a peak detecting means for detecting a peak of the voltage received from the differential amplifying means and transmitting the detected peak to the filtering means.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of an embodiment of a power control apparatus using current sampling according to the present invention.

As shown in FIG. 2, the power control apparatus using the current sampling according to the present invention includes: a power supply unit 20 for supplying power and power amplification for amplifying power by receiving power from the power supply unit 20. The unit 21, a current sampling unit 22 for obtaining a voltage by sampling a current applied from the power supply unit 20 to the power amplifier 21, and a voltage level received from the current sampling unit 22. The level adjusting unit 23 for adjusting, the differential amplifier 24 for differentially amplifying the voltage level received from the level adjusting unit 23, and the level according to the transmission on signal TX ON from the control unit 29. The operation controller 28 for controlling the operation of the adjuster 23 and the differential amplifier 24, the filter 26 for removing noise of the voltage received from the differential amplifier 24, and the filter 15 Digital voltage An analog-to-digital converter 27 for converting into a call, and a transmission on signal (TX ON) to the operation control unit 28, the power according to the digital signal received from the analog-to-digital converter 27 A control unit 29 for controlling the transmission power of the amplifier 21.

On the other hand, the present invention further includes a peak detector 25 for detecting the peak of the voltage received from the differential amplifier 24 to output to the filter 26.

3 is a circuit diagram of an embodiment of a power control apparatus using current sampling according to the present invention.

First, the current sampling unit 22 is a portion for sampling the current as a voltage. The current sampling unit 22 inserts a resistor 0.15 Ω 301 in series between the power supply unit 20 and the power amplifier unit 21 to provide a voltage between the A and B points. Find [V (AB)].

The level adjuster 23 adjusts the sampled voltage [V (AB)] to match the input level of the operational amplifier 310 of the differential amplifier 24. At this time, as shown in the figure, if the voltage is divided by the resistance of 1KΩ (302, 304) and the resistance of 3.9KΩ (303, 305), the voltage [V (A'B ')] between points A' and B 'is known. Can be.

On the other hand, the differential amplifier 24 includes two 22KΩ (306, 308), two 560KΩ (307, 309) and the operational amplifier 310 to differentially amplify the input voltage, and accordingly output voltage [V ( out)].

On the other hand, the peak detector 25 as an additional component, including a Schottky diode (311) and a capacitor (312) of 100nF performs a peak detection function, and the data rate (Data Rate) It is used for stabilization in case is not full rate.

On the other hand, the filter (LPF) 26 includes a 47KΩ 313 and a 100nF capacitor 314 to perform the function of the low pass filter (LPF) of the signal received from the differential amplifier 24 Remove the noise.

In addition, the operation controller 28 includes a transistor 315, a first resistor 316, and a second resistor 317, and when the transmission on signal TX ON from the controller 29 is high, The transistor 315 is turned on to operate the level adjuster 23 and the differential amplifier 24.

On the other hand, when the transmission on signal TX ON from the controller 29 is low, the operation control unit 28 turns off the transistor 315 so that the level adjusting unit 23 and the The differential amplifier 24 is not operated. Therefore, it is possible to prevent the power supply of the power supply 20 from wasting when the transmission on signal TX ON is low.

Looking at the operation of the circuit shown in Figure 3 in detail as follows.

First, the voltage V at the point B (V (B)) in the current sampling unit 22 is equal to the voltage of the power supply unit (battery) 20, and the voltage at the A point V (A) is the power amplifier 21. Since the level is down in proportion to the current [I [PAM]] consumed by the PAM, the voltage at the A point is expressed by Equation 1 below.

V (A) = V (B)-0.15 × I (PAM)

Therefore, the voltage [V (AB)] between point A and point B is as shown in Equation 2 below.

 V (AB) = 0.15 × I (PAM)

However, since V (A) and V (B) are almost equal to the operating voltage [V +] level of the operational amplifier 310, if this level is input to the two input terminals of the differential amplifier 24 as it is, the operational amplifier 310 ) Does not work properly. Accordingly, the level adjuster 23 adjusts the input level so that the operational amplifier 310 can operate normally.

By the level adjusting section 23, the voltages V (A ') and V (B') at points A 'and B' are 3.9 / (1 + 3.9) times V (A) and V (B), respectively. Accordingly, the voltage [V (A'B ')] between the point A' and the point B 'is expressed by Equation 3 below.

V (A'B ') = V (AB) × 3.9 / (1 + 3.9) = 0.8 × V (AB)

The voltage V (A'B ') is amplified and output by 560/22 through the differential amplifier 24, and the output voltage V (out) is expressed by Equation 4 below.

V (out) = V (A'B ') × (560K / 22K) = 25.5 × V (A'B') = 20.3 × V (AB)

Therefore, the output voltage is about 20 times the sampled voltage, and is stably transmitted to the analog / digital converter 27 through the peak detector 25 and the filter 26. Thereafter, the controller 29 controls the transmission power of the power amplifier 21 according to the digital signal received from the analog / digital converter 27.

At this time, in one embodiment, but designed as '20 times amplification 'as a suitable multiple for experiment, it is possible to adjust the multiple by adjusting the plurality of resistance values in some cases.

As described above, the current flowing through the power amplification unit 21 (PAM) was detected up to almost 700 mA, and the specifications of the maximum output power were matched through power calibration of the wireless communication terminal. Could satisfy.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

As described above, the present invention has the effect of accurately controlling the transmission power by using the voltage level obtained by sampling and converting the current consumed by the power amplifier instead of directly detecting the radio frequency signal transmitted by the power amplifier. have.

In addition, the present invention has the effect of reducing the power loss due to the conventional coupler because it samples the current consumed by the power amplifier.

In addition, the present invention has an effect of preventing waste of power by operating in accordance with an operation control signal (transmission on signal TX ON).

Claims (4)

In the power control device using the current sampling, Current sampling means for sampling a current applied from the external power supply means to the external power amplifying means to obtain a voltage; Level adjusting means for adjusting a voltage level received from the current sampling means; Differential amplifying means for differentially amplifying the voltage level received from the level adjusting means; Operation control means for controlling the operation of said level adjusting means and said differential amplifying means in accordance with an operation control signal; Filtering means for removing noise of the voltage received from the differential amplifying means; Conversion means for converting the voltage filtered by the filtering means into a digital signal; And Control means for transmitting an operation control signal to the operation control means and controlling the transmission power of the power amplification means according to the digital signal received from the conversion means; Power control device using a current sampling comprising a. The method of claim 1, Peak detection means for detecting the peak of the voltage received from the differential amplification means for transmitting to the filtering means Power control device using a current sampling further comprising. The method according to claim 1 or 2, The current sampling means, And a resistor connected in series between the power supply means and the power amplification means. The method of claim 3, wherein The operation control means, The level adjusting means and the differential amplifying means are operated so as to receive a high operation control signal from the control means, and the low operation control signal is received from the control means. And a level adjusting means and the differential amplifying means do not operate.

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