KR100312304B1 - Balance amplifier circuit using detector and thereof method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balanced power amplifier circuit and amplification method using a detector for facilitating adjustment of amplification characteristics of a power amplifier in a balanced power amplifier circuit of a radio frequency (RF) band used in a communication system. A divider for dividing an input signal of the first and second signals, a first detector for detecting and outputting a first signal distributed by the divider, a first amplifying stage for amplifying the first signal transmitted through the first detector, and A second detector for detecting and outputting a signal output from the first amplifier stage, a third detector for detecting a second signal distributed by the divider, a second amplifier stage for amplifying the second signal transmitted through the third detector, and a second amplifier stage A fourth detector for detecting a signal output from the second detector, a combiner for combining the signal detected by the second detector with the signal detected by the fourth detector, and outputting the first internal Each of the amplified stages measured by the spectrum analyzer means and the spectrum analyzer means for measuring the magnitudes of the input and output signals of the first and second amplifier stages detected by the first to fourth detectors, respectively. And adjusting means for comparing the magnitudes of the input signals and the output signals, and using the comparison results to adjust the amplification characteristics of each amplifier stage.

Description

BALANCE AMPLIFIER CIRCUIT USING DETECTOR AND THEREOF METHOD

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balanced amplifier circuit and an amplification method thereof, and particularly to easily adjust amplification characteristics of a power amplifier in a balanced power amplifier circuit of a radio frequency (RF) band used in a communication system. The present invention relates to a balanced power amplifier circuit and method using a detector.

In general, an amplifier in a radio frequency band used in a wireless communication system uses a structure of a balance amplifier configured by connecting two amplifier stages in parallel to increase the maximum output power. The balanced amplifier has the advantage that the overall amplification characteristic is improved compared to the general amplifier because each amplifier stage amplifies only half of the input signal.

1 shows a configuration diagram of a balanced amplifier according to the prior art, and as shown, a splitter 110 for distributing an input signal of a radio frequency band into two paths, and one of the signals distributed by the splitter 110. A first amplifying stage 120 for amplifying the first signal, a second amplifying stage 130 for amplifying a second signal which is another one of the signals distributed by the divider 110, and an output of the first amplifying stage 120; Composed of a combiner 140 for combining and outputting the output of the second amplification stage 130, the operation and effects thereof will be described as follows.

The first amplifying stage 120 and the second amplifying stage 130 are transferred through the first matching circuit 122 and 132 and the first matching circuit 122 and 132 respectively connected to the distributor 110. And a second matching circuit 126 and 136 for transmitting the signal amplified by the transistors 124 and 134 to the combiner 140.

The balanced amplifier configured as described above divides the input signal by half by using the 3dB combiner 110 and the divider 140 at the input stage and the output stage, respectively, and at the first and second amplifier stages 120 and 130. Combine the amplified signal.

In this case, each of the amplification stages 120 and 130 includes a plurality of passive elements and adjusts the matching circuits 122, 126, 132, and 136 for impedance matching for each device. 134 operates in a particular frequency domain.

In the balance amplifier operating as described above, the balancing amplifier according to the related art is divided into two methods. The first adjustment method according to the prior art first measures each input and output of two amplifier stages operating independently without being connected to a divider or combiner, so that each amplifier stage performs good amplifier performance in a specific frequency range. Adjust the phase and gain of each. The two amplifier stages are then connected to the splitter and combiner respectively, and the input and output of the overall balance amplifier are measured again to confirm that the balance amplifier operates normally.

However, the first adjustment method has the inconvenience of adjusting each amplifier stage and then connecting the adjusted amplifier stages to the distributor and the combiner and rechecking the function of the overall balance amplifier.

Therefore, the second method of adjusting the balance amplifier according to the related art to solve the above inconvenience is to connect the two amplifier stages to the divider and the combiner, and then measure the input and output of the overall balance amplifier, so that the balance amplifier has a specific frequency range. Adjust the phase and gain of each amplifier stage to achieve good amplifier performance.

The second adjustment method is simpler than the first adjustment method. However, since the gain of each amplification stage is adjusted by measuring only the output of the overall balance amplifier, the difference between the signal sizes output from the two amplification stages is different. The resulting losses could reduce the overall balance amplifier output. In addition, when the difference in the output signal period is very large, an excessive load may be applied to the transistor of one amplifier stage.

In other words, the conventional amplifier has a problem in that the input and output of the two amplifiers cannot be measured after connecting the two amplifier stages to the splitter and the combiner.

Therefore, an object of the present invention, which was devised to solve the problems of the prior art operated as described above, is to connect each amplifier stage with two amplifier stages connected to a distributor and a combiner in order to facilitate the adjustment of the overall characteristics of the balanced amplifier. The present invention provides a balanced power amplifier circuit and an amplification method using a detector including a detector capable of detecting an input signal and a signal output from each amplifier stage.

1 is a block diagram of a balance amplifier according to the prior art.

2 is a view showing an embodiment of a balanced power amplifier circuit configuration using a detector according to the present invention.

<Explanation of symbols for main parts of the drawings>

110: divider 120,130: amplification stage

122,126,132,136: Matching circuit 124,134: Transistor

140: combiner 210: divider

220,240,250,270: Detector 230,260: Amplifier

232,236,262,264: matching circuit 234,264: transistor

280: combiner 290: load

Embodiments of the balanced power amplifier circuit using a combiner according to the present invention, which is designed to achieve the above object, includes: a divider for distributing an input signal of a radio frequency band into first and second signals; A first detector for detecting and outputting the first signal; a first amplifier for amplifying the first signal transmitted through the first detector; a second detector for detecting and outputting a signal output from the first amplifier; A third detector for detecting the second signal distributed by the distributor; a second amplifier for amplifying the second signal transmitted through the third detector; a fourth detector for detecting a signal output from the second amplifier stage A combiner configured to combine and output the signal detected by the second detector and the signal detected by the fourth detector; respectively connected to the first to fourth detectors. Spectrum analyzer means for the first to fourth detector detects one of the first and respectively measuring the amplitude of the input signal and the output signal of the second amplifier stage;

And adjusting means for comparing the magnitudes of the input signals and the output signals of the respective amplification stages measured by the spectrum analyzer means, and adjusting the amplification characteristics of the respective amplification stages using the comparison results.

In accordance with another aspect of the present invention, there is provided a method of amplifying a balanced power amplifier using a combiner, comprising: distributing an input signal of a radio frequency band input from a signal source into a first signal and a second signal; Detecting a first signal; amplifying the first signal at a first amplifier stage; detecting the amplified first signal at a second detector; detecting the second divided signal at a third detector Amplifying the second signal in a second amplifier stage; detecting the amplified second signal in a fourth detector; combining and outputting the amplified first and second signals in a combiner; Using a spectrum analyzer connected to each of the fourth detectors, the magnitude of the detected first signal, the magnitude of the amplified first signal, the magnitude of the detected second signal, and the amplified agent Measuring a magnitude of each of the two signals; comparing the magnitude of the detected first signal with the magnitude of the amplified first signal, and comparing the magnitude of the detected second signal with the magnitude of the amplified second signal. Doing;

And adjusting amplification characteristics of the first amplifier stage and the second amplifier stage by using the comparison result.

The present invention further includes an input signal detector for detecting a signal input to two amplifier stages and an output signal detector for detecting a signal output from the two amplifier stages to facilitate adjustment of amplification characteristics of the balanced amplifier. Circuit and method.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention.

2 shows an embodiment of a balanced power amplifier circuit configuration using a detector according to the present invention, as shown, a divider 210 for distributing an input signal of a radio frequency band to a first and a second path; A first detector (220) for detecting the first signal, which is one of the signals distributed by the distributor (210); A first amplifying stage (230) for amplifying a first signal transmitted through the first detector; A second detector 240 for detecting a signal output from the first amplifier stage 120; A third detector (250) for detecting the second signal, which is another one of the signals distributed by the divider (110); A second amplifying stage 260 for amplifying a second signal transmitted through the third detector; A fourth detector 270 for detecting a signal output from the second amplifier stage 260; It is composed of a combiner 280 for combining and outputting the signal transmitted through the second detector 240 and the signal transmitted through the fourth detector 270, the operation and effects thereof will be described as follows.

The first amplifier stage 230 includes a first transistor 234 and a first transistor for amplifying a signal transmitted through the first matching circuit 232 and the first matching circuit 232 connected to the first detector 220. The second matching circuit 126 transfers the signal amplified by the first transistor 234 to the second detector.

In addition, the second amplifier stage 260 may include a second transistor 264 and amplify a signal transmitted through the third matching circuit 262 and the third matching circuit 262 connected to the third detector 250. The fourth matching circuit 136 transfers the signal amplified by the second transistor 264 to the fourth detector 270.

In order to adjust the balanced power amplifier circuit configured as described above, the load 290 is connected to the coupler 280 so that the signal output from the combiner 280 flows to the ground through the load 290.

The balanced power amplifier circuit divides the input signal by half by using the 3dB combiner 210 and the divider 280 at the input stage and the output stage, respectively, and is amplified by the first and second amplifier stages 230 and 260. Combine the signals.

In this case, each of the amplifier stages 230 and 260 adjusts the first to fourth matching circuits 232, 236, 262 and 266, which are composed of a plurality of passive elements. The two transistors 234 and 264 operate in a particular frequency domain.

The signal input to the balanced power amplifier circuit is divided into first and second signals by the splitter 210 and the separated first and second signals are amplified by the first and second amplifiers 230 and 260, respectively. do. The first and second signals amplified by the first and second amplifier stages 230 and 260, respectively, flow into the load 290 coupled at the combiner 280 and then connected to the termination.

In this case, the first and second detectors 220 and 240 detect an input signal and an output signal of the first amplification stage 230, respectively, and the third and fourth detectors 250 and 270 are the second amplification stage 260. Respectively detect the input signal and the output signal.

In order for the amplification characteristics (phase and gain) of the first and second amplification stages 230 and 260 to be the same, the user may apply a spectrum to the first to fourth detectors 220, 240, 250, and 270. Each analyzer is connected and the spectrum analyzer is used to measure the magnitude of the signal detected by each detector.

For example, in order to adjust the amplification characteristics of the first amplifier 230, the spectrum analyzer is connected to the port 1 of the first detector 220 and the port 2 of the second detector 240, respectively, 1 The magnitude of the input signal and the output signal of the amplifier 230 is measured.

When the magnitudes of the measured input signal and the output signal are compared, the amplification characteristics of the first amplifier 230 can be known. Therefore, the user can compare the magnitude of the measured amplitude of the input signal with the output signal. The amplification characteristics of the first amplifier stage 230 are adjusted by adjusting the first and second matching circuits 232 and 236 of 230.

In addition, in order to adjust the amplification characteristics of the second amplification stage 260, the user connects the spectrum analyzer to the port 3 of the third detector 250 and the port 4 of the fourth detector 270, respectively, The magnitude of the input signal and the output signal of the second amplifier stage 260 is measured using the spectrum analyzer.

When the measured input signal and the output signal are compared, the amplification characteristics of the second amplifying stage 260 can be known. Therefore, the user can use the result of comparing the measured input signal with the output signal. By adjusting the third and fourth matching circuits 262 and 266, the amplification characteristics of the second amplifying stage 260 are adjusted.

At this time, the user uses the comparison result of the first amplifier 230 and the second amplifier 260, so that the amplification phase and the amplification gain of the two amplifiers 230, 260 are the same, the two amplifiers 230, 260 Adjust the amplification characteristics.

After adjusting the amplification characteristics of the two amplifier stages 230 and 260, the user measures the amplification characteristics of the entire balanced power amplifier circuit. To this end, the user removes the load 290 connected to the combiner 280, instead connects an attenuator and spectrum analyzer to the combiner 280 and then measures the final output signal of the balanced power amplifier circuit. The attenuator is for attenuating the magnitude of the signal output from the combiner 280 to a range that can be measured by the spectrum analyzer.

The magnitude of the final output signal measured is compared with the magnitude of the input signal initially input to the balanced power amplifier circuit. An example of a method of calculating the magnitude of the final output signal is as follows.

The gain of the first and second amplifier stages 230, 260 is equal to G [dB], the loss of the divider 210 is L1 [dB] and the loss of the combiner 280 is L2 [dB]. When the loss caused by the difference in signal sizes of the first and second amplifying stages 230 and 260 is D [dB], the magnitude of the signal input to the balanced power amplifier circuit is referred to as I [dBm]. The final output signal of the balanced power amplifier circuit is shown in Equation 1.

Final output signal = I-(L1 + L2)-D + G

As described above, the final output signal is determined by Equation 1, and as described above, using the first to fourth detectors 220, 240, 250, and 270, the first and second If the amplification characteristics of the amplifier stages 230 and 260 are equally adjusted, the loss D due to the difference in the signal sizes of the two amplifier stages 230 and 260 is reduced.

When the loss D decreases, the final output signal increases by Equation (1). Also, if the final output signal measured is known, the loss D can be calculated.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

In the present invention, in adjusting the characteristics of a balanced amplifier used in a radio frequency communication system, two amplifier stages are inserted into a balanced power amplifier circuit so as to detect an input signal and an output signal of each amplifier stage while being connected to a splitter and a combiner. By using the input / output signal detector, the characteristics of the matching circuit can be easily adjusted.

Therefore, the present invention has an effect that the characteristics of the balanced amplifier can be efficiently adjusted by reducing the difference in signal size between the amplifier stages generated by separately adjusting the characteristics of each amplifier stage.

Claims (9)

A divider for distributing an input signal of a radio frequency band into first and second signals; A first detector for detecting and outputting the first signal distributed by the distributor; A first amplifier stage for amplifying the first signal transmitted through the first detector; A second detector for detecting and outputting a signal output from the first amplifier stage; A third detector for detecting the second signal distributed by the distributor; A second amplifying stage for amplifying the second signal transmitted through the third detector; A fourth detector for detecting a signal output from the second amplifier stage; A combiner for combining and outputting the signal detected by the second detector and the signal detected by the fourth detector; Spectrum analyzer means connected to the first to fourth detectors, respectively, for measuring magnitudes of input and output signals of the first and second amplification stages detected by the first to fourth detectors; An equilibrium power amplification using a detector, comprising adjusting means for comparing the magnitudes of the input signals and the output signals of the respective amplifier stages measured by the spectrum analyzer means and using the comparison results to adjust the amplification characteristics of the respective amplifier stages. Circuit. The method of claim 1, wherein each of the first and second amplification stages, A first matching circuit receiving the first signal or the second signal; A transistor connected in series to a rear end of the matching circuit and amplifying a signal transmitted through the matching circuit; And a matching circuit connected in series to a rear end of the transistor and transferring a signal amplified by the transistor to the detector. The balanced power amplifier circuit of claim 1, wherein each of the first to fourth detectors includes a resistor having one side connected to each of the first to fourth detectors and the other side grounded. 2. The balanced power amplifier circuit of claim 1, wherein one side further comprises a load connected to the combiner and the other side is grounded. Dividing an input signal of a radio frequency band input from a signal source into a first signal and a second signal; Detecting the distributed first signal at a first detector; Amplifying the first signal at a first amplifier stage; Detecting the amplified first signal at a second detector; Detecting the second divided second signal at a third detector; Amplifying the second signal at a second amplifier stage; Detecting the amplified second signal at a fourth detector; Combining and outputting the amplified first and second signals in a combiner Using a spectrum analyzer connected to each of the first to fourth detectors, the magnitude of the detected first signal, the magnitude of the amplified first signal, the magnitude of the detected second signal, and the amplitude of the amplified second signal. Measuring each size; Comparing the magnitude of the detected first signal with the magnitude of the amplified first signal and comparing the magnitude of the detected second signal with the magnitude of the amplified second signal; And adjusting the amplification characteristics of the first amplifier stage and the second amplifier stage using the comparison result. The method of claim 9, wherein each of the first and second amplification stages, An amplification method of a balanced power amplifier circuit using a detector, comprising a transistor and first and second matching circuits connected in series with each other with the transistor interposed therebetween. 10. The method of claim 9, wherein adjusting the amplification characteristics of the first amplification stage and the second amplification stage is performed such that the amplification characteristics of the first amplification stage and the amplification characteristics of the second amplification stage are the same. Amplifying method of a balanced power amplifier circuit using a detector for adjusting the amplification characteristics of the first amplifier stage and the second amplifier stage. The method of claim 9, further comprising: after adjusting the amplification characteristics of the first amplifier stage and the second amplifier stage, measuring a magnitude of a signal output from the combiner; And amplifying characteristics of the entire balanced power amplifier circuit by comparing the magnitude of the signal output from the combiner with the magnitude of the input signal input from the signal source. The method of claim 14, wherein the measuring of the magnitude of the signal output from the combiner comprises: And amplifying a signal output from the combiner using an attenuator and a spectrum analyzer connected in series to a rear end of the combiner.