Experimental Investigation of Resistive–Reactive Class-J Mode Using Time-Domain Low-Frequency Active Harmonic Load–Pull Measurements

Advances in Microwave Large-Signal Metrology: From Vector-Receiver Load-Pull to Vector Signal Network Analyzer and Time-Domain Load-Pull Implementations (Invited Paper)

“…Two methods are used to identify these waveforms: from simulations using CAD tools [30] or from large-signal measurements [31][32][33][34]. In order to study the behavior of a power amplifier using CAD tools, nonlinear transistor models are required; thus, the capabilities of the transistor model to represent the device large-signal behavior heavily impacts the accuracy of this method [35]. By comparison, waveform measurements using commercial high-frequency (HF) load-pull systems [31,32] require the use of state-of-the-art measurement equipment, such as a nonlinear vector network analyzer or a large-signal network analyzer [36].…”

“…In Figure 17, the schematic diagram and picture of the time-domain LF active harmonic load-pull system developed in [35] is shown. In [35] the system operation was extensively described; in this paper a brief review of the measurement system functionality is provided.…”

“…In Figure 17, the schematic diagram and picture of the time-domain LF active harmonic load-pull system developed in [35] is shown. In [35] the system operation was extensively described; in this paper a brief review of the measurement system functionality is provided. The main elements of the system are a four-channel oscilloscope and directional couplers, which allow sensing of the waves at the input and output ports of the DUT, along with other elements that allow the system to properly operate, such as bias networks, DC power supplies, and driver power amplifiers to boost the signals at the DUT ports.…”

Isothermal Characterization of Traps in GaN HEMTs Operating in Class B Using a Real-Time Pulsed-RF NVNA Testbed

“…A sampler-based NVNA using a sampling oscilloscope was reported in [4]. Low-frequency, oscilloscope-based analyzers have also recently been developed to reveal CW large-signal loadlines of devices [5], [6]. However, these systems operate at very low frequencies and do not necessarily require rigorous NVNA calibration.…”

Research and realization of 150W ultra-wideband reconfigurable RF power amplifier

“…Currently, there are various options for realizing broadband matching, and excellent performance can be obtained over a wide bandwidth by utilizing a filter-matching network structure [1,2,3,4], [5] based on the method of designing a broadband matching network in [1], a PA operating from 1.9 to 4.3 GHz was developed and excellent performance was obtained. To obtain a larger bandwidth while maintaining high efficiency, continuous class structures have been proposed [6,7] (continuous class J and continuous class F theories), and there have been a large number of related PAs based on them reported in the literature since then [8,9,10,11,12,13,14,15,16], but due to the second harmonic control required by the high efficiency, these structures are often limited to bandwidths up to one octave. The reconfigurable structure is also an effective way to expand the bandwidth [17,18,19,20,21,22,23,24,25,26,27], which utilizes reconfigurable switches to switch the matching network, and is characterized by simple design method and flexible circuit structure.…”