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In this paper we report a novel slow wave structure which is evolved from traditional folded wave guide for THz back-ward wave oscillators (BWOs). The back-ward wave impedance of the novel slow wave structure is much higher than traditional folded wave guide, and the PIC simulation results show that the output power can reach 100mW, which is a good candidate of THz for sources for fusion plasma diagnostics.
This paper presents a 38 GHz 2-stage harmonic-tuned power amplifier consisted of a class-F−1 output power amplifier proceeded by a class-AB driving stage in 0.13 µm SiGe BiCMOS technology. In order to shape highly efficient class-F−1 current and voltage waveforms, the PA adopts multi-resonance series and parallel load networks that modulate load impedance to generate an optimum 50-Ω for signal band,...
In this paper, the design of slow wave structures for an X-band broadband TWT with suppression of backward-wave using the helix pitch step method is present. An optimized design of a high-power X-band broadband TWT with improved BWO suppression and forward-wave saturated output power is presented.
The International Electrotechnical Committee Technical Report IEC 61000-3-15:2011 provides electromagnetic compatibility requirements and test conditions for distributed generators up to 75 A per phase. In the current research, two commercially available photovoltaic (PV) inverters up to the capacity of 3600 W were tested following the guidelines proposed in IEC 61000-3-15 in relation to low order...
A novel, highly efficient and broadband RF power amplifier (PA) operating in “continuous class-F” mode has been realized for first time. The introduction and experimental verification of this new PA mode demonstrates that it is possible to maintain expected output performance, both in terms of efficiency and power, over a very wide bandwidth. Using recently established continuous class-F theory, an...
A continuum of closed-form solutions for voltage waveforms resulting from a complex load at the fundamental and reactive terminations at certain harmonic frequencies is analytically derived for Inverse Class-F power amplifiers based on a finite number of harmonics. The continuum of solutions shows constant RF output power and efficiency for a range of fundamental reactances and appropriately chosen...
This paper presents a novel formulation for the inverse class-F mode of operation, termed the “continuous inverse class-F mode”, resulting in an extended or continuous set of ‘allowed’ current waveforms. In comparison to the classical inverse class-F mode, this approach provides a much wider design space for the realization of broadband power amplifiers, where output performance can be maintained...
The practical operating conditions of class-F−1 amplifier are investigated by analyzing the current and voltage waveform shapings. The bifurcated current of the amplifier is generated by the saturated operation at the knee region, resulting in quasi-rectangular current. The voltage shaping is studied for the active device with linear and nonlinear output capacitors (Couts). In the linear Cout case,...
The influence of the harmonic impedances on the power amplifier performance is presented across a wide bandwidth. Based on this method, a set of impedances for the first, second and third harmonics across the band was found which do not affect output power (POut) and power added efficiency (PAE). At the 3 dB compression point, the measured Pout is 40 dBm ± 1.5 dB, and the PAE is between 58.7 %-78...
In this paper, a narrow band pass Alter with reduced size using the λg/4 short stubs is presented. The filter size is reduced by realization of transmission line at the second harmonic while the power can be transferred to the output using the fundamental frequency band generated in the resonator and the transmission line in which the impedance mismatching technique is adopted. The experimental results...
In this paper, the power quality of a single-phase photovoltaic grid connected inverter when uses active islanding detection methods is investigated. Two main groups of these methods are analyzed in this paper. The main focus is on the output power quality of PV sources for these methods. Also the variation of output current THD, while the output power changes, is explored. The variation of output...
Class D amplifiers are becoming the most feasible solution for embedded audio application. However, distortions due to the non-linear nature of switching stage are the main drawback for this amplifier topology. This paper discusses the design and implementation of high fidelity audio class D using sliding mode control scheme. This design method proves to be a cost effective solution for industrial...
In this paper, a design method of harmonic output impedance control for high efficient power amplifiers is proposed. The high efficiency of the power amplifier is achieved by using control of the second and third harmonic output impedances at optimized fixed fundamental output impedance. The 1 GHz measured results of the harmonically tuned power amplifier yielded 78 % power added efficiency at the...
A large-signal measurement-based methodology to design oscillators using the Kurokawa theory is presented in this paper. Measurements of the negative input resistance and device line of a 2.5 GHz HEMT oscillator versus frequency and power, and its optimization using real-time active load-pull (RTALP) for the 2nd and 3rd harmonics are performed with a large signal network analyzer (LSNA). As a result,...
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