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DC circuit design can be done using Agilent advanced design system simulator. The DC simulation circuit is designed to define bias point and bias network. This is require in order to select the amplifier class of operation and power to be consumed by the device. The drain source voltage (VDS) is set to 28 volts, while the gate source voltage (VGS) is 2.4 volts respectively. This means that the bias condition has been set at the voltage source. However, these values have been recommended in the data sheet by the manufacturer. The design was simulated and drain source current (IDS) was achieved at 45mA as shown in figure 2. The DC quiescent current was achieved to prevent signal distortion [4, 5]. Like the main purpose of DC simulation is to specify the class of operation and the DC quiescent current is to prevent signal distortion. Bias circuit was also designed based on class-AB carrier. A good biasing prevents signal reflection and distortions. In addition to setting the bias network component values, linecalc from ADS simulator is to determine the length of micro-strip transmission lines required in the design. However, the lateral MOSFET MRF826060HSR3 transistor require no matching process, as the input and output impedances are internally matched in the device. The following RT 5880 subsirate specifications have been applied to achieve 21mm _ length of micro-strip line: H =

Figure 2 DC circuit design can be done using Agilent advanced design system simulator. The DC simulation circuit is designed to define bias point and bias network. This is require in order to select the amplifier class of operation and power to be consumed by the device. The drain source voltage (VDS) is set to 28 volts, while the gate source voltage (VGS) is 2.4 volts respectively. This means that the bias condition has been set at the voltage source. However, these values have been recommended in the data sheet by the manufacturer. The design was simulated and drain source current (IDS) was achieved at 45mA as shown in figure 2. The DC quiescent current was achieved to prevent signal distortion [4, 5]. Like the main purpose of DC simulation is to specify the class of operation and the DC quiescent current is to prevent signal distortion. Bias circuit was also designed based on class-AB carrier. A good biasing prevents signal reflection and distortions. In addition to setting the bias network component values, linecalc from ADS simulator is to determine the length of micro-strip transmission lines required in the design. However, the lateral MOSFET MRF826060HSR3 transistor require no matching process, as the input and output impedances are internally matched in the device. The following RT 5880 subsirate specifications have been applied to achieve 21mm _ length of micro-strip line: H =

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components and intermodulation distortion in power amplifier is a foremost apprehension _ for communication systems engineering [1]. The effects result to apparent presence of nonlinearity on the frequency band. These however, lead to power loss and adjacent channel interference. To mitigate these effects of nonlinearity and achieve state of the art system, it is obligatory to prudently design and implement the power amplifier for high speed data rate and spectral efficiency. A healthier power amplifier design is an exceptional candidate for technologies such as_ multiple-input-multiple-output (MIMO), wireless land area network (WLAN), orthogonal frequency division multiplexing (OFDM), spatial modulation transmitters and several more 5G applications. The features of such systems embrace high speed data rate, wider bandwidth and higher spectral efficiency [2, 3]. This paper presents a discussion on the design of balanced RF power amplifier, the effect of nonlinearity and impact of adaptive digital pre-distorter in transmission system. Section Il presents balanced power amplifier circuit design and performance results. Section Ill discusses adapting modified Saleh model for adaptive digital pre-distortion. Section IV presents conclusion of the paper.
components and intermodulation distortion in power amplifier is a foremost apprehension _ for communication systems engineering [1]. The effects result to apparent presence of nonlinearity on the frequency band. These however, lead to power loss and adjacent channel interference. To mitigate these effects of nonlinearity and achieve state of the art system, it is obligatory to prudently design and implement the power amplifier for high speed data rate and spectral efficiency. A healthier power amplifier design is an exceptional candidate for technologies such as_ multiple-input-multiple-output (MIMO), wireless land area network (WLAN), orthogonal frequency division multiplexing (OFDM), spatial modulation transmitters and several more 5G applications. The features of such systems embrace high speed data rate, wider bandwidth and higher spectral efficiency [2, 3]. This paper presents a discussion on the design of balanced RF power amplifier, the effect of nonlinearity and impact of adaptive digital pre-distorter in transmission system. Section Il presents balanced power amplifier circuit design and performance results. Section Ill discusses adapting modified Saleh model for adaptive digital pre-distortion. Section IV presents conclusion of the paper.
A balanced power amplifier linear simulation was conducted using Agilent advanced design system simulator (ADS) and result was obtained from 2.620 to 2.690GHz frequency band. The results have shown a good flat gain (S2,1) and outstanding return loss ((S1,1) and (S2,2)).
A balanced power amplifier linear simulation was conducted using Agilent advanced design system simulator (ADS) and result was obtained from 2.620 to 2.690GHz frequency band. The results have shown a good flat gain (S2,1) and outstanding return loss ((S1,1) and (S2,2)).
The balanced power amplifier designed for MISO WLAN-OFDM application using adaptive digital pre- distortion due to nonlinear distortions is presented. The amplitude and phase modulation distortions being the coefficients extracted from single tone simulations are characterize using MATLAB software platform. Curve fitting tool in MATLAB converts the amplitude and phase modulation coefficients to generate polynomials. The polynomials are used in developing the modified Saleh model algorithm for the adaptive digital pre-distortion system [8, 9].
The balanced power amplifier designed for MISO WLAN-OFDM application using adaptive digital pre- distortion due to nonlinear distortions is presented. The amplitude and phase modulation distortions being the coefficients extracted from single tone simulations are characterize using MATLAB software platform. Curve fitting tool in MATLAB converts the amplitude and phase modulation coefficients to generate polynomials. The polynomials are used in developing the modified Saleh model algorithm for the adaptive digital pre-distortion system [8, 9].
To improve this model, a simple algorithm for linear equation was developed to characterize the AM-AM and AM-PM polynomials of the balanced power amplifier as shown is equation 3 and 4. It is applied in the adaptive digital pre-distortion to linearize the signal and compensate for the nonlinear distortion produced by the power amplifier [8]. To implement the transfer functions, the extracted data was measured in the environment of normalized input voltage against the output voltage of the balanced power amplifier. Figure 8 has shown the extracted data based on amplitude modulation, plotted with the following curve fittings: ag = 33.066, as = - 85.52, a, = 82.06, a3 = -34.052, ao = 2.85, a; = 3.21 and a = -0.01. The AM-AM characterization was effected by the device reaching a saturation point.
To improve this model, a simple algorithm for linear equation was developed to characterize the AM-AM and AM-PM polynomials of the balanced power amplifier as shown is equation 3 and 4. It is applied in the adaptive digital pre-distortion to linearize the signal and compensate for the nonlinear distortion produced by the power amplifier [8]. To implement the transfer functions, the extracted data was measured in the environment of normalized input voltage against the output voltage of the balanced power amplifier. Figure 8 has shown the extracted data based on amplitude modulation, plotted with the following curve fittings: ag = 33.066, as = - 85.52, a, = 82.06, a3 = -34.052, ao = 2.85, a; = 3.21 and a = -0.01. The AM-AM characterization was effected by the device reaching a saturation point.
performance of the pre-distorter, the balanced power amplifier was designed. The implemented balanced power amplifier in the context of amplitude and phase measured data was imported in a Simulink, developed based on IEEE 802.16 MISO WLAN-OFDM transceiver system. The memoryless nonlinearity performance of the modified Saleh model has been evaluated. Performance results of the transmitter is shown in igure 10 and 11. Figure 10 illustrates the amplitude and phase signals of the balanced power amplifier, reproduced by the transceiver system, without inearization. While figure 11 illustrates the amplitude and phase signals, linearized by the adaptive digital pre-distorter. Hence, the transceiver system was set oO run on modified Saleh model with digital pre- distortion to compensate the nonlinearity of the balanced power amplifier.
performance of the pre-distorter, the balanced power amplifier was designed. The implemented balanced power amplifier in the context of amplitude and phase measured data was imported in a Simulink, developed based on IEEE 802.16 MISO WLAN-OFDM transceiver system. The memoryless nonlinearity performance of the modified Saleh model has been evaluated. Performance results of the transmitter is shown in igure 10 and 11. Figure 10 illustrates the amplitude and phase signals of the balanced power amplifier, reproduced by the transceiver system, without inearization. While figure 11 illustrates the amplitude and phase signals, linearized by the adaptive digital pre-distorter. Hence, the transceiver system was set oO run on modified Saleh model with digital pre- distortion to compensate the nonlinearity of the balanced power amplifier.
Fig. 11. AM-AM and AM-PM responses with linearization. Fig. 10. AM-AM and AM-PM_ responses without linearization.
Fig. 11. AM-AM and AM-PM responses with linearization. Fig. 10. AM-AM and AM-PM_ responses without linearization.
Journal of Multidisciplinary Engineering Science and Technology (JMEST) ISSN: 2458-9403 eae ee ee ee |, a eee eee eee y.T PT
Journal of Multidisciplinary Engineering Science and Technology (JMEST) ISSN: 2458-9403 eae ee ee ee |, a eee eee eee y.T PT
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