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The paper explores the investigation of an inverse Class‐E amplifier featuring a series output filter across various switch‐off duty ratios D. Analysis of different duty ratios as a design parameter reveals their impact on peak switch voltage, output power capability, and maximum operating frequency. Notably, it is demonstrated that adjusting the D ratio affects these parameters, with specific emphasis on achieving a maximum normalized switch voltage lower than 2 and an output power capability exceeding 0.1 for D = 0.7. Furthermore, the paper considers both parasitic shunt capacitance and series inductor in the load network, a departure from previous works that solely focused on the series inductor. The proposed circuit is highlighted for its ease of implementation compared with conventional reactance compensation circuits employing parallel resonant circuits, which are challenging to form directly. An innovative approach is introduced to showcase the broadband performance of the inverse Class‐E amplifier. The measured drain efficiency and output power versus input power at 430 MHz are 82% and 45.3 dBm, respectively. A similar performance can be achieved within the frequency range of 380–600 MHz by proper tuning at saturated power. The measurement results demonstrate a maximum high power‐added efficiency (PAE) of 79% and drain efficiency of 82% within this frequency range, accompanied by a gain exceeding 12.0 dB and output power surpassing 44 dBm. [ABSTRACT FROM AUTHOR]

In this paper, a Doherty power amplifier based on an inverse Class‐E amplifier with a series output filter are presented. The proposed inverse Class‐E amplifier has been designed and simulated using lumped elements and transmission lines (TL), respectively. The high‐performance simulation results of TL inverse Class‐E PA with an output power of 46.2 dBm, peak drain efficiency of 71%, and a power gain of 27 dB at an input power 18 dBm have been obtained. Finally, the Doherty power amplifier (DPA) based on the inverse Class‐E power amplifier with some asymmetry in two paths has been designed and implemented. Implementation of both carrier and peaking amplifiers with an inverse Class‐E load network can provide an increase in the efficiency and improvement of harmonic suppression levels. Maximum drain efficiencies of 69.3% and 54% at maximum output power level (50 dBm) and 7‐dB back‐off power level (43 dBm) have been measured, respectively. [ABSTRACT FROM AUTHOR]

This paper presents the theoretical analysis of the Class-E/F3 power amplifier (PA) with nonlinear shunt capacitor at different grading coefficient (m), for both optimum (i.e., ZVS and ZVDS) and suboptimum (i.e., ZVS and non-ZVDS) operations. The effects that the grading coefficient has on the load network parameters, maximum operating frequency, and the peak switch voltage and current are investigated in details for m = 0 up to m = 0.8. Three design examples are given to explain the design procedure, and two circuit prototypes were built using power MOSFETs with m = 0.3 and m = 0.5 to validate the theory. The constructed PAs delivered an output power of 3.5 W/2.55 W and a drain efficiency of 92.3%/92% at an operating frequency of 3.8/3.85 MHz, respectively. [ABSTRACT FROM AUTHOR]

In this paper, a microstrip high selectivity filtering power divider with coupling from source/load to the resonator is designed. By employing pairs of parallel‐coupled lines and asymmetrical T‐shaped resonators to construct the filtering power dividers (PD), high selectivity, and good return loss can be achieved with two transmission poles and two transmission zeros. The design procedure and analytical equations are obtained by using the even/odd‐mode analysis. The power divider operating at the central frequency of 2.1 GHz with a 3‐dB fractional bandwidth of 19% (1.9–2.4 GHz) is simulated and implemented. Good agreement between measurement and simulated results is obtained. By introducing a resistor between output ports, the isolation is better than 18.4 dB at the passband frequency, respectively. Also, the second harmonic rejection and insertion loss lower than 0.38 dB has been obtained. [ABSTRACT FROM AUTHOR]

In this paper, a wideband filtering Wilkinson power divider embedded with square‐loop resonators and short‐circuit stubs is designed and presented. Shunt short‐circuit meander line stubs are utilized at both output ports to provide extra transmission zeros (TZs) at 7, 14, and 19 GHz. Moreover, the square‐loop resonators, which are placed along the conventional λ/4 transmission lines, provide TZs at 9 and 14 GHz. Over the frequency range from 3 to 6 GHz, insertion loss of 0.3 dB, return loss greater than 12 dB and isolation better than 10 dB have been obtained. The proposed power divider has a compact size of 0.237 λg × 0.415 λg. Finally, the proposed circuit has been fabricated, and the measurement results have a good agreement with the simulation results. [ABSTRACT FROM AUTHOR]

A single-ended Class-E/Fn power amplifier (PA) with linear external and nonlinear drain-to-source (intrinsic) capacitances is designed and analyzed to achieve optimum operation. The effects of nonlinear intrinsic and linear external capacitance at high and low frequencies increase, respectively. The different specifications of the Class-E/F3 PA are shown versus the external and intrinsic capacitances. A Class-E/F3 amplifier at 4-MHz frequency, based on the theoretical results, is analyzed, simulated, and fabricated. The efficiency, power gain, and output power versus the input power are presented as well. The measured results are close to the analytical derivations at optimum conditions of zero-voltage switching and zero-voltage-derivative switching. [ABSTRACT FROM AUTHOR]

In this study, the Class‐E/F3 power amplifier with linear gate‐to‐drain and nonlinear drain‐to‐source capacitance is proposed. The analysis for the effect of the parasitic capacitance in the mixed mode Class‐E/F3 with square and sinusoidal gate‐to‐source voltage has been done. Most of the design equations in this study do not have analytical solutions, and the numerical analyses are used. As can be seen, there is little difference between the results related to the sinusoidal and square gate‐to‐source voltage. So, only the simulation and experimental result for Class E/F3 with square gate‐to‐source voltage at operating frequency of 4 MHz has been done. The results in this study indicate that it is important to consider the effect of the MOSFET gate‐to‐drain capacitance for achieving the ZVS/ZDS conditions in the Class‐E/F3 power amplifier. The PSpice simulation and measured results are agreed with the analytical expressions, which show the validity of the presented analytical expressions. Finally, the waveforms of Class E/F3 are compared with equivalent waveforms of Class‐E power amplifier, in order to indicate its advantages. [ABSTRACT FROM AUTHOR]

In this paper, the Class-Fn/E power amplifier (PA) and the inverse Class-E (Class- \mboxE^-1) PA under zero-current switching and zero-current-derivative switching conditions at any duty ratio are analyzed. The maximum switch voltage and current, output power capability, and element values as functions of the duty ratio are obtained for both classes. The main objective of the analysis is to choose the proper duty ratio to maximize the output power capabilities at optimum conditions. The element values are dependent upon the duty ratio and require a careful selection of the duty ratio to reach desired specification. The effect of the duty ratio D=0.3-0.7 on the performance of the Class- \mboxE^-1 and Class-F3/E PAs is demonstrated. The duty ratio is used not only as the design specification but also as the adjusting parameter for achieving a certain condition. The measured maximum drain efficiency of 88% and 87% are obtained at 4 MHz at 30-dBm input power for the Class-F3/E and Class- \mboxE^-1 PAs, respectively. The results show that lower peak switch voltage and current are obtained in the Class-F3/E PA in comparison with Class- \mboxE^-1 for the same conditions. [ABSTRACT FROM PUBLISHER]

In this paper, the analysis and comparison of a Class- E/F3 power amplifier with nonlinear and linear shunt capacitance at 50% duty ratio are presented. An analytical analysis for nonlinear and linear shunt capacitance is presented, and its effects on the performance of the power amplifier are discussed. The different parameters, such as series reactance, peak switch voltage, and power output capability are compared for power amplifiers with linear and nonlinear shunt capacitance. Two design examples of the Class-E/F3 power amplifiers with IRF530 MOSFETS and lumped elements at an operating frequency of 4 MHz are analyzed. The PSpice simulation and measurement for the power amplifier with nonlinear shunt capacitance have been done. The results agree with the analytical expressions that show the validity of the analytical expressions derived at zero-voltage switching and zero derivative voltage switching conditions. [ABSTRACT FROM AUTHOR]

A compact microstrip lowpass filter (LPF) with an elliptic function response is proposed. A high equivalent capacitance and inductance between the structures of the resonator result in the sharp transition band of 0.04 GHz from 4 GHz to 4.04 GHz with an attenuation level of -3 dB and -20 dB, respectively. To improve the LPF rejection band, multiple open stubs are connected to the proposed resonator. A filter with a 3-dB cut-off frequency at 4 GHz is designed, fabricated, and measured, and agreement between the measured and simulated results is achieved. The results show that a stopband bandwidth of 131% with a suppression level better than -20 dB is obtained while achieving a compact size with a wide stopband. [ABSTRACT FROM AUTHOR]

A novel lowpass filter with a very sharp transition band and wide stopband is proposed. The proposed filter is based on T-shaped patches which are etched in symmetrical structures and folded open stub. To obtain a wide stopband, we have used stub loaded semi-circle stepped-impedance structures. By designing the resonator with high inductance and capacitance, a very sharp transition band is achieved. The proposed filter has a 3-dB cutoff frequency at 2.37 GHz and a 40-dB rejection at 2.44 GHz. The stopband with an attenuation level better than -13.2 dB is up from 2.4 GHz to 16 GHz, and consequently we have reached the high and wide rejection in stopband with compact size. Good agreements between the simulated and the measured results are presented. [ABSTRACT FROM AUTHOR]

In this paper, an ultra-high capacity 64-channel optical communication system using a single mode fiber is presented. The proposed system investigates the performance of optical network based on two methods of Duo-Binary modulation format at 10, 20 and 40 Gbps bit rates and distance of 1500 Km. Performance of the proposed under different modulation formats has been studied. The simulated results show that two methods are efficient. Also, the first method of DuoBinary modulation format in ultra-high capacity optical network at 40 Gbps bit rate has better performance. It is proved that quality factor and bit error rate are function of fiber length. [ABSTRACT FROM AUTHOR]