KR100606773B1 - Apparatus for Detecting Transmitting Power of The Mobile Communication Device - Google Patents

Abstract

The present invention relates to a power detection device for more securely detecting the transmission power in the terminal without affecting the transmission path in the mobile communication terminal, the power detection device for detecting the transmission power in the transmission path in the mobile communication terminal, A branch line coupler formed on an inner layer of a PCB to detect transmission power from a transmission path in a terminal, and detecting a phase change of transmission power detected by the branch line coupler. It is configured to include a phase comparator for.

Therefore, the present invention can minimize the sensitive response to external environmental factors by not only affecting the transmission path and peripheral circuits in the terminal by implementing the power detection device in the circuit board, but in the transmission line. In other words, it is possible to improve the signal state on the wireless transmission and reception path and to maximize the accuracy of power detection.

Transmit Power / Branch-Line Coupler

Description

Apparatus for Detecting Transmitting Power of The Mobile Communication Device

1 is a block diagram showing an apparatus for detecting a transmission power of a mobile communication terminal according to the prior art;

2A and 2B show an embodiment of the power detection device of FIG.

3 is a diagram illustrating an apparatus for detecting a transmission power of a mobile communication terminal according to the present invention.

4 shows the layout of a branch line coupler.

* Explanation of symbols for main parts of the drawings

100: power amplifier

200: Branch-Line Coupler

300: phase comparator

The present invention relates to a transmission power detection device of a mobile communication terminal, and more particularly, to a power detection device for more safely detecting the transmission power generated inside the terminal without affecting the circuit on the transmission path.

In general, the mobile communication terminal increases the output power, that is, the transmitting power, in proportion to the distance from the base station.

The reason is that the farther away from the base station, the weaker the received signal strength indicator (RSSI) and the higher the error rate of the signal, the lower the error rate of the signal by increasing the output power.

Accordingly, in order to more accurately control the output power, the output power of the terminal was examined by placing a power detector between the power amplifier and the antenna.

1 is a view partially illustrating a transmission related configuration of a conventional mobile communication terminal.

As illustrated, the wireless signal output from the drive amplifier 10 is an input of the power amplifier 20.

The signal output to the antenna 30 through the power amplifier 20 is detected by the power detector 40, wherein the signal detected by the power detector 40 is an A / D converter (Analog to Digital). After converting into a digital signal through the converter (50) is transmitted to the control unit (60).

The conventional power detector 40 detects the transmission power of the terminal output to the antenna 30 and can be implemented using various elements.

For example, as shown in FIG. 2A, a passive element such as a coupler may be used at the same time, and an active element directly connected on a line as shown in FIG. 2B may be used. Power detection means can be used.

However, in the conventional transmission power detecting apparatus, the power detector 40 may have a high impedance and may adversely affect other circuits in which a loop is formed.

In other words, since the power detector 40 is directly connected to the transmission path in the mobile communication terminal, the power detection unit 40 has a significant effect on the peripheral circuits, and thus mismatch and path loss between signals on the radio (RF) transmission / reception path. There was a problem that caused (Path Loss).

In addition, using a separate power detection means without directly constructing a circuit on a line as a method for reducing the influence on the transmission path has only caused power loss and space limitation.

In addition, the power detection means for detecting the transmission power in the mobile communication terminal has been a problem of lowering the accuracy of power detection because it reacts sensitively to environmental factors, in particular, temperature changes.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a transmission power detection apparatus that does not directly affect the transmission path of the mobile communication terminal.

Another object of the present invention is to improve the signal condition in the transmit / receive path as well as the accuracy of power detection.                         

Still another object of the present invention is to provide a transmission power detecting apparatus capable of responding to environmental factors (temperature / humidity change).

In order to achieve the above object, the present invention provides a power detecting apparatus for detecting a transmission power in a transmission path in a mobile communication terminal, which is formed in an inner layer of a terminal circuit board (PCB) and transmitted from a transmission path in the terminal. The present invention provides a transmission power detecting apparatus of a mobile communication terminal including a branch line coupler for detecting power and a phase comparator for detecting a phase change of the transmission power detected by the branch line coupler.

Here, the branch line coupler outputs a first port outputting the transmission power detected in the transmission line by internal coupling and a signal having a phase difference of 90 ° compared to the output of the first port. A second port, a third port for outputting a signal having a 180 ° phase difference with respect to the output of the first port, and a second terminal connected to a ground terminal for isolation between the second port and the third port. It is characterized by having 4 ports.

The phase comparator uses the outputs of the second port and the third port of the branch line coupler as input signals, and outputs the phase difference between the two input signals as an output signal. And a loop for feeding back an output to the first port of the branch line coupler.

According to the present invention, it is possible to detect the transmission power without affecting the peripheral circuit of the transmission path by implementing the transmission power detection device of the mobile communication terminal using the branch line coupler and the phase comparator.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

Referring to Figures 3 and 4, the transmission power detection apparatus of the mobile communication terminal according to the present invention will be described.

First, as shown in FIG. 3, the apparatus for detecting power of the present invention includes a power amplifier 100 for amplifying a wireless transmission signal in a mobile communication terminal, and a wireless signal amplified by the power amplifier 100 to the outside. Branch line coupler (Branch-) formed in the inner layer of the antenna (not shown) for transmission and printed circuit board (PCB) for detecting the transmission power from the transmission line between the power amplifier 100 and the antenna A line comparator 200 and a phase comparator 300 for detecting a phase change of the transmission power detected by the branch line coupler 200.

The present invention implements a branch line coupler 200 for detecting transmission power in the inner layer of the printed circuit board of the terminal for the purpose of not affecting the transmission line in the mobile communication terminal.

As shown in FIG. 4, a series arm pattern, a shunt arm pattern, and a port (①, ②, ③, ④) pattern of the branch line coupler 200 are formed on the inner surface of the circuit board. do.

Here, when the port impedance is Zo, the impedance Zp of the shunt arm is equal to the port impedance Zo, and the impedance Zr of the series arm is equal to 1 / SQRT {2} of the port impedance Zo. Form a pattern as much as possible.

For example, when the port impedance Zo is 50 kV, the shunt arm impedance Zp is 50 kV, and the series arm impedance Zr is 35.4 kV.

Coupling of the branch line coupler 200 is determined by the impedance ratio of the shunt arm and the series arm.

The transmission power on the transmission line is detected by the coupling degree of the branch line coupler 200. Port ① receives and outputs the transmission power detected on the line, and port ② has a phase difference of 90 ° compared with the output of port ①. Outputs a signal of size 1/2.

In addition, the port ③ has a 180 ° phase difference compared to the output of the port ① and outputs a 1/2 size signal, and the port ④ does not output and is connected to the ground terminal to reinforce the insulation between the port ② and the port ③. .

By using the branch line coupler 200, it is possible to implement a power detection device that does not need to be directly connected to a transmission line and does not affect a peripheral circuit of a transmission path.

Furthermore, the present invention uses the phase comparator 300 as a means for detecting a change in transmit power.

The phase comparator 300 receives outputs of ports ② and port ③ having a 90 ° and 180 ° phase difference, respectively, as input signals compared to the port ① of the branch line coupler 200.

Here, when the phase difference between the two input signals of the phase comparator 300 is 90 degrees or more, the output of the phase comparator 300 forms a loop fed back to the port ① of the branch line coupler 200.

Preferably, the two input signals of the phase comparator 300 have a phase difference of 90 °, but the transmission power is changed by external environmental factors such as temperature and humidity, so that the phase difference between the two input signals may be different.

Accordingly, the phase comparator 300 may be used to compare phases of two input signals, and the output of the phase comparator 300 may be inputted by a control means (not shown) of a terminal to monitor a change in transmission power. That is, the phase comparator 300 may correspond to a change in the transmission power.

The present invention is not limited to the above-described embodiments, and can be modified by those skilled in the art as can be seen from the appended claims, and such modifications are within the scope of the present invention.

The effects of the apparatus for detecting transmission power of a mobile communication terminal according to the present invention described above are as follows.

First, it is possible to improve the signal state on the wireless transmission and reception path by implementing a power detection device that does not affect the transmission path and the peripheral circuit of the mobile communication terminal.

Second, by implementing the transmission power detection device on the inner layer of the circuit board rather than the transmission line, it is possible to maximize the accuracy of power detection by minimizing the response to external environmental factors.                     

Third, since the change in the transmission power can be detected, it is possible to quickly respond to the instantaneous power change in the terminal, thereby improving system reliability.

Claims (4)

A power detection device for detecting a transmission power in a transmission path in a mobile communication terminal, Branch-line coupler (Branch-Line Coupler) formed in the inner layer of the terminal circuit board (PCB) for detecting the transmission power from the transmission path in the terminal, And a phase comparator for detecting a phase change of the transmission power detected by the branch line coupler. The method of claim 1, The branch line coupler A first port for outputting the transmission power detected in the transmission line by internal coupling; A second port for outputting a signal having a phase difference of 90 ° relative to the output of the first port, A third port for outputting a signal having a phase difference of 180 ° relative to the output of the first port, And a fourth port connected to a ground terminal for isolation between the second port and the third port. The method of claim 2, The phase comparator And a phase difference between the two input signals as an output signal using the outputs of the second port and the third port of the branch line coupler as output signals. The method of claim 3, wherein And a loop for feeding back the output of the phase comparator to the first port of the branch line coupler when the phase difference between the two input signals is greater than 90 ° in the phase comparator.

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