KR100326567B1 - Method and Apparatus for stable MAX power in a mobile communication terminal - Google Patents

Abstract

The present invention relates to a maximum power stabilization apparatus and a method of a mobile communication terminal for quickly stabilizing maximum power by directly controlling a bias of an RF transmitter drive amplifier using high power detection. As such, the present invention includes a maximum power stabilization unit that adjusts the bias voltage of the drive amplifier by varying the output of the DC converter so that the preset maximum power stabilization value is maintained in the maximum power measurement mode.

In addition, the present invention determines whether the current mode is the normal mode or the maximum power measurement mode, and if the mode determination result, in the maximum power measurement mode to control the bias control of the drive amplifier, and set the measured maximum power value When the maximum power stabilization reference value is compared and the measured maximum power value is the same as the maximum power stabilization reference value, it is determined that the maximum power is stabilized and the transmission power measurement mode is switched, and the measured maximum power value and the maximum power stabilization are determined. If the reference value is different, the bias voltage of the drive amplifier is varied to control the maximum power value to reach the maximum power stabilization reference value.

Description

Maximum power stabilization apparatus and method for mobile communication terminal {Method and Apparatus for stable MAX power in a mobile communication terminal}

The present invention relates to the stabilization of the maximum power (MAX Power) of the mobile communication terminal in the mobile communication system, in particular, by directly controlling the bias (bias) of the RF transmitter drive amplifier using high power detection (High Power Detection), The present invention relates to a maximum power stabilization device and a method of a mobile communication terminal to stabilize the maximum power.

In general, in a CDMA mobile communication system, a mobile communication terminal solves a problem that may occur due to non-linearity of hardware (H / W), and maintains linearity between input and output to provide a dynamic range of 80 Hz or more. To ensure this, adjust RX gain (RX AGC), TX gain (TX AGC), and MAX Power.

Here, RX and TX adjustment is a process for linearly compensating for nonlinear characteristics, and MAX Power adjustment is a process for adjusting power so as to produce a constant MAX power for all channels.

However, since the gain (AGC) of the RF TX input stage is adjusted during MAX Power adjustment, there may be errors in each terminal, and it is not possible to take a perfect measure for changes that may occur in the RF intermediate stage.

Of course, to compensate for the temperature change, a temperature sensor is used to compensate the temperature properly.However, since the voltage is generated by the heat felt by the sensor and the current change is predicted and compensated for, the actual power is applied. Since the change and the temperature change are not linearly correlated, a more reliable compensation method is needed.

To this end, high power detection is currently being applied to mobile communication terminals. This is a method of coupling the power to a range that does not affect the output of the power amplifier, converting the coupling value into direct current (DC), and then stabilizing the maximum power by using the change of the DC voltage.

1 is a block diagram illustrating a configuration of a maximum power stabilization apparatus of a mobile communication terminal to which a conventional high power detection method is applied.

Here, reference numeral 10 denotes a drive amplifier for driving the processed baseband transmission signal into an RF signal, and reference numeral 20 denotes a saw filter for filtering the transmission signal output from the drive amplifier 10 to a specific band. 30 denotes a power amplifier that amplifies the transmission signal output from the saw filter 20 and outputs the result to an isolator.

In addition, reference numeral 40 denotes a coupler for coupling the transmission signal output from the power amplifier 30 and outputting the power detection signal, and reference numeral 50 denotes the power detection signal output from the coupler 40 as a DC voltage. A DC converter to be converted is indicated, and reference numeral 60 denotes a level amplifier for amplifying the DC voltage output from the DC converter 50.

In addition, reference numeral 70 denotes a baseband processor for converting the power detection signal output from the level amplifier 60 into 2 bits of data in the baseband, and reference numeral 80 denotes the baseband processor 70 that is output from the baseband processor 70. The mobile station modem outputs a gain control signal for controlling the transmission signal gain in accordance with a 2-bit power detection signal.

In the conventional power stabilization apparatus of the conventional mobile communication terminal configured as described above, the transmission signal processed as the baseband by the baseband processor 70 sequentially passes through the drive amplifier 10 and the saw filter 20, and then the power amplifier 30. Power is amplified at and delivered to the isolator at the front end.

At this time, the coupler 40 detects the power level of the transmission signal output from the power amplifier 30, and the DC converter 50 converts the power level detection signal of the transmission signal output from the coupler 40 into a DC voltage. The level amplifier 60 adjusts the DC voltage to match the input level.

Next, the baseband processor 70 converts the power level detection signal output from the level amplifier 60 into 2 bits of data in the baseband and transmits the data to the mobile station modem 80.

The mobile station modem 80 retrieves the detected power level and outputs an automatic gain control signal AGC ADJUST to the baseband processor 70 to maintain the maximum power at a constant level according to the preprogrammed content. To control the output level.

In this way, the maximum power is stabilized.

However, when the maximum power is stabilized by the feedback method, it takes a long time to stabilize the maximum power.

There is no problem in the manual test (CDMA TEST equipment: SPEC TEST by manual operation using HP-8924C), but in the procedure for obtaining FCC approval, the automatic test using PCMIC CARD rather than manual test (automatically by programmed procedure) The high power detection algorithm cannot follow the maximum power checking time of the HP-8924C.

In other words, when measuring the maximum power while changing the channel, or measuring the maximum power after the minimum power measurement, the HP-8924C device performs power check before the high power detection algorithm is applied, and the stabilized output is finished. There is a problem that comes next.

In this case, the actual maximum power is stabilized, but the SPEC results are not obtained.

Accordingly, the present invention has been proposed to solve various problems occurring in the maximum power stabilization device of the mobile communication terminal applying the conventional high power detection algorithm as described above.

SUMMARY OF THE INVENTION An object of the present invention is to provide a maximum power stabilization apparatus for a mobile communication terminal which is capable of quickly stabilizing maximum power by directly controlling bias of an RF transmitter drive amplifier by using high power detection. To provide a way.

The maximum power stabilization device of the mobile communication terminal according to the present invention for achieving the above object,

A mobile communication terminal comprising a drive amplifier, a saw filter, a power amplifier, an isolator, a coupler for coupling the output of the power amplifier to detect the maximum power, a DC converter for converting the output of the coupler to a DC voltage, a baseband processor, and a mobile station modem. In the maximum power stabilization device of,

And a maximum power stabilization unit configured to adjust a bias voltage of the drive amplifier by varying an output of the DC converter so that a predetermined maximum power stabilization value is maintained in the maximum power measurement mode.

The maximum power stabilization unit may include an operational amplifier for operational amplifying the DC voltage output from the DC converter, a bias current regulating resistor for adjusting a bias current by adjusting an output of the operational amplifier, and a selected mode measuring the maximum power. In the mode, the first switching element for controlling the gain of the drive amplifier by supplying a bias control voltage through the bias current adjusting resistor to the drive amplifier side, and when the selected mode is the normal mode of the reference voltage supplied to the drive amplifier And a second switching element for supplying a bias voltage through the reference bias current adjusting resistor to the drive amplifier in the normal mode.

In addition, the maximum power stabilization method of the mobile communication terminal according to the present invention for achieving the above object,

In the maximum power stabilization method of the mobile communication terminal,

Determining whether the current mode is the normal mode or the maximum power measurement mode;

Controlling the bias of the drive amplifier in the maximum power measurement mode as a result of the mode determination, and comparing the measured maximum power value with a set maximum power stabilization reference value;

If the measured maximum power value is equal to the maximum power stabilization reference value, determining that the maximum power is stabilized and switching to a transmission output measurement mode;

And when the measured maximum power value and the maximum power stabilization reference value are different from each other, controlling the maximum power value to reach the maximum power stabilization reference value by varying a bias voltage of the drive amplifier. .

The controlling of the maximum power value may include adjusting a bias voltage to reduce the gain of the drive amplifier when the measured maximum power value is greater than the maximum power stabilization reference value, and the measured maximum power value is the maximum power. When the bias is less than the stabilization threshold, characterized in that the step of adjusting the bias voltage to increase the gain of the drive amplifier.

1 is a block diagram showing the configuration of a maximum power stabilization device of a conventional mobile communication terminal,

2 is a block diagram showing the configuration of a maximum power stabilization device of a mobile communication terminal according to the present invention;

3 is a circuit diagram showing a detailed configuration of each part of FIG.

4 is a flowchart illustrating a maximum power stabilization method of a mobile communication terminal according to the present invention.

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

10 ..... Drive Amplifier

80 ..... Mobile station modem

90 ..... Maximum Power Stabilizer

91 ..... Op Amps

R5 ..... bias current regulation resistor

Q2, Q1 ..... First and second switching elements

Hereinafter, described in detail with reference to the accompanying drawings, preferred embodiments of the present invention according to the technical spirit as described above.

Example 1

2 is a block diagram showing a configuration of a maximum power stabilization device of a mobile communication terminal according to the present invention.

Here, reference numeral 10 denotes a drive amplifier for driving the processed baseband transmission signal into an RF signal, and reference numeral 20 denotes a saw filter for filtering the transmission signal output from the drive amplifier 10 to a specific band. Reference numeral 30 denotes a power amplifier for power amplifying the transmission signal output from the saw filter 20 and outputting the result to an isolator, and reference numeral 40 couples the transmission signal output from the power amplifier 30. The reference numeral 50 denotes a DC converter for converting the power detection signal output from the coupler 40 into a DC voltage, and the reference numeral 60 denotes a coupler outputting the power detection signal. A level amplifier for amplifying the DC voltage, and reference numeral 70 denotes a power detection signal output from the level amplifier 60 to the baseband. A baseband processor for converting data into 2-bit data, and reference numeral 80 denotes a mobile station modem for outputting a gain control signal for controlling a transmission signal gain in accordance with a 2-bit power detection signal output from the baseband processor 70. Indicates.

This configuration is the same as the configuration of the maximum power stabilization device of the conventional mobile communication terminal, the present invention is configured to output the output of the DC converter 50 in such a configuration, so that the maximum power stabilization value set in advance in the maximum power measurement mode is maintained. It is configured to include a maximum power stabilization unit 90 to adjust the bias voltage of the drive amplifier 10 by varying.

The maximum power stabilization unit 90 includes an operational amplifier 91 for operational amplifying the DC voltage output from the DC converter 50 and a bias for regulating a bias current by adjusting an output of the operational amplifier 91. When the selected mode is the maximum power measurement mode and the current control resistor (R5), the bias control voltage through the bias current control resistor (R5) is supplied to the drive amplifier 10 side to adjust the gain of the drive amplifier (10) A first switching element Q2, a reference bias current adjusting resistor R6 for adjusting a current of a reference voltage supplied to the drive amplifier 10 when the selected mode is a normal mode, and the reference in the normal mode. The second switching element Q1 supplies a bias voltage through the bias current regulating resistor R6 to the drive amplifier 10.

Operation of the maximum power stabilization device of the mobile communication terminal according to the present invention configured as described above is as follows.

Generally, in case of CDMA terminal in maximum power of transmit power, J-STD-018 defines 0.2W ~ 1W (23dBm ~ 30dBm), and the standard required for FCC approval is 300mW +/- 10% (24.77dBm) It is prescribed below.

To meet these conditions, a procedure is required to adjust the maximum power to + 24dBm with some margin, which is called RAS-RAM adjustment.

First, the normal mode, not the maximum power measurement, is when the power control is in ClosedLoop.

In this case, the high power detection, the temperature compensation, and the like are methods for compensating for the change or loss of the output power occurring in the maximum power state, and in this case, it is not necessary to operate the maximum power stabilizer 90 according to the present invention.

Accordingly, the mobile station modem 80 controls the bases of the first and second switching elements Q2 and Q1 in the maximum power stabilization unit 90 in logic mode in the normal mode. Then, the first switching element Q2 is turned off, and only the second switching element Q1 is turned on.

As the second switching element Q1 is turned on, the voltage Vcc is controlled through the turned-on second switching element Q1 in a state in which the bias current is controlled through the reference bias current regulating resistor R6. The bias voltage is then provided to the drive amplifier 10.

In this case, the bias point of the drive amplifier 10 may be designed to have a normal gain.

At this time, the circuit for high power detection is in operation, but since the first switching element Q2 is turned off, there is no effect on other devices.

Next, in the maximum power measurement mode, the mobile station modem 80 controls the bases of the first and second switching elements Q2 and Q1 in the maximum power stabilization unit 90 to logic zero.

In this case, the output signal of the power amplifier 30 is combined in the coupler 40 formed of the resistor R1 and the capacitor C1, and the coupled signal is transmitted to the DC converter 50.

As shown in FIG. 3, the DC converter 50 half-wave rectifies the output signal of the coupler 30 with the half-wave rectifying diode D4, and makes the DC voltage using L1 and C2. In addition, the filter is made of a filter consisting of R2, C3, and transmits the result to the maximum power stabilizer (90).

Here, the half-wave rectification may not be possible in the half-wave rectifying diode D4 because the coupled power is relatively low. In this case, the DC offset is applied by the Vt voltage of the half-wave rectifying diode D4, so that all of the positive signals are passed to achieve smooth half-wave rectification.

On the other hand, the maximum power stabilization unit 90 outputs 2.4V ~ 2.8V inverted with respect to the DC voltage input to the operational amplifier 91. For example, the resistor R4 and the capacitor C4 are designed such that when the input DC voltage changes from 1.0 to 1.4V, the output of the operational amplifier 91 varies from 2.8 to 2.4V. The other DC inputs are in normal mode, so any output that does not affect the circuit.

As such, the voltage output from the operational amplifier 91 is controlled by the bias current adjusting resistor R5, and the first switching element Q2 turned on by the logic 0 signal output from the mobile station modem 80. Through the bias voltage is provided to the drive amplifier 10.

In this case, the bias voltage may be calculated in advance in the bias voltage capable of stabilizing the unstable maximum power, and the bias current regulation resistor R5 may be designed accordingly. For example, when the gain of the drive amplifier 10 is a maximum of 20 mA, the voltage for controlling the bias current through the bias resistor R5 is designed to be changed from 2.4 to 2.8 V to 16 to 20 mA.

In further detail, in order to help the understanding of the present invention described above is as follows.

For this purpose, we assume a stabilized maximum power at + 24dBm, a DC output of 1.2V, and an op amp output of 2.6V.

If the unstabilized maximum power is higher than 24dBM, the DC voltage will be higher than 1.2V. Through the inverting operational amplifier 91, its output is lower than 2.6V. In this case, the bias current is reduced so that the bias voltage of the drive amplifier 10 is reduced, thereby reducing the gain of the drive amplifier 10. As a result, the maximum power is stabilized at 24dBm.

As another example, when the unstabilized maximum power is lower than 24 dBm, the DC voltage is lower than 1.2V. Through inverting operational amplifier 91, its output is higher than 2.6V. In this case, the bias current is increased so that the bias voltage of the drive amplifier 10 is increased, thereby increasing the gain of the drive amplifier 10. As a result, the maximum power is stabilized at 24dBm.

Herein, the mobile station modem 80 looks at a process of controlling the first and second switching elements Q2 and Q1 in the maximum power stabilization unit 90 as follows.

The first and second switching elements Q2 and Q1 are operated immediately upon receiving an UP signal at all times from the measuring device HP-8924C, and the time at which the actual unstable maximum power is output. Control in less time is no problem for maximum power measurement.

Example 2

4 is a flowchart illustrating a maximum power stabilization method of a mobile communication terminal according to the present invention.

As shown therein, determining whether the current mode is the normal mode or the maximum power measurement mode (S11); In the normal mode, controlling the reference bias voltage to be provided to the drive amplifier 10 (S12); Controlling the bias of the drive amplifier in the maximum power measurement mode as a result of the mode discrimination, and comparing the measured maximum power value with a set maximum power stabilization reference value (S13 to S14); If the measured maximum power value is equal to the maximum power stabilization reference value, determining that the maximum power is stabilized and switching to a transmission output measurement mode (S15 to S16); When the measured maximum power value and the maximum power stabilization reference value are different from each other, a step of controlling the maximum power value to reach the maximum power stabilization reference value by varying the bias voltage of the drive amplifier is performed (S17 to S19).

In the above, the maximum power value control step (S17 ~ S19), the step of adjusting the bias voltage to reduce the gain of the drive amplifier when the measured maximum power value is greater than the maximum power stabilization threshold (S17 ~ S18), When the measured maximum power value is smaller than the maximum power stabilization reference value, the bias voltage is adjusted to increase the gain of the drive amplifier (S17 and S19).

In the method of stabilizing the maximum power of the mobile communication terminal according to the present invention as described above, first, in step S11, it is determined whether the current mode is the normal mode or the maximum power measurement mode.

As a result of the determination, in the normal mode, the first switching element Q2 in the maximum power stabilization unit 90 is turned off in step S12 to control to operate in the normal mode.

On the contrary, in the determination result of the maximum power measurement mode, the first switching element Q2 in the maximum power stabilization unit 90 is turned on in step S13.

Then, it is compared whether the maximum power value measured in step S14 is equal to the preset maximum power stabilization reference value (24 dBm).

If the measured maximum power value is the preset maximum power stabilization reference value as a result of this comparison, the flow advances to step S16 to switch to the mode of measuring the transmission power level.

Next, when the measured maximum power value is different from the preset maximum power stabilization reference value as a result of the comparison, it is checked in step S17 whether the measured maximum power value is larger than the preset maximum power stabilization reference value.

As a result of this check, when the measured maximum power value is larger than the preset maximum power stabilization reference value, the bias voltage is controlled to reduce the gain of the drive amplifier 10 in step S18.

In addition, when the measured maximum power value is smaller than the preset maximum power stabilization reference value, the bias voltage is controlled to increase the gain of the drive amplifier 10 in step S19.

According to the above-described 'maximum power stabilization apparatus and method of the mobile communication terminal' according to the present invention, it is possible to accurately measure the power at the time of measuring the maximum power, and also has the advantage of stabilizing the maximum power quickly.

In addition, since a program required for high power detection is not required, the memory required for executing the existing high power detection algorithm can be removed, thereby providing an easy circuit configuration and reducing the manufacturing cost of the mobile communication terminal.

Claims (4)

A mobile communication terminal comprising a drive amplifier, a saw filter, a power amplifier, an isolator, a coupler for coupling the output of the power amplifier to detect the maximum power, a DC converter for converting the output of the coupler to a DC voltage, a baseband processor, and a mobile station modem. In the maximum power stabilization device of, Maximum power stabilization of the mobile terminal characterized in that it comprises a maximum power stabilization unit for adjusting the bias voltage of the drive amplifier by varying the output of the DC converter so that the predetermined maximum power stabilization value is maintained in the maximum power measurement mode Device. The method of claim 1, wherein the maximum power stabilization unit, An operational amplifier for operational amplifying the DC voltage output from the DC converter, a bias current regulating resistor for adjusting a bias current by regulating the output of the operational amplifier, and the bias current regulating resistor when the selected mode is the maximum power measurement mode. The first switching device for adjusting the gain of the drive amplifier by supplying a bias control voltage through the drive amplifier side, and the reference bias current control for adjusting the current of the reference voltage supplied to the drive amplifier when the selected mode is the normal mode And a second switching element for supplying a bias voltage through the reference bias current adjusting resistor to the drive amplifier in the normal mode. In the maximum power stabilization method of the mobile communication terminal, Determining whether the current mode is the normal mode or the maximum power measurement mode; Controlling the bias of the drive amplifier in the maximum power measurement mode as a result of the mode determination, and comparing the measured maximum power value with a set maximum power stabilization reference value; If the measured maximum power value is equal to the maximum power stabilization reference value, determining that the maximum power is stabilized and switching to a transmission output measurement mode; And when the measured maximum power value and the maximum power stabilization reference value are different, controlling the maximum power value to reach the maximum power stabilization reference value by varying a bias voltage of the drive amplifier. Maximum power stabilization method of a mobile communication terminal. The method of claim 3, wherein the maximum power value control step, Adjusting the bias voltage to reduce the gain of the drive amplifier when the measured maximum power value is greater than the maximum power stabilization threshold; and gain of the drive amplifier when the measured maximum power value is less than the maximum power stabilization threshold. And adjusting the bias voltage so as to increase the maximum power.