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This paper presents a simple and universal measurement method for the average efficiency and instantaneous efficiency of pulsed RF power amplifiers. The average efficiency of the traditional definition varies with different duties and thus lacks universality, because of the DC power consumption outside the RF pulse. In our proposed method, the DC power consumption within a pulse period is divided into different parts. The parameters of each part can be extracted-from simple measurements of the average voltage and current under different duties. The average efficiency and instantaneous efficiency of different duties can be calculated with the extracted parameters. Since current clamps or oscilloscopes are not necessary to measure the instantaneous voltage and current, this solution can be easily implemented in a simple and cost-effective way, to expand the application into compact and sealed circuits. Measurement uncertainties under different duties were analyzed of the method. Experimental results of the proposed method are consistent with theoretical efficiencies, which help validate the method. INDEX TERMS Average efficiency, instantaneous efficiency, efficiency measurement, pulsed RF power amplifier, uncertainty analysis, various duties.

This paper presents an automatic piecewise (Auto-PW) extreme learning machine (ELM) method for S-parameters modeling radio-frequency (RF) power amplifiers (PAs). A strategy based on splitting regions at the changing points of concave-convex characteristics is proposed, where each region adopts a piecewise ELM model. The verification is carried out with S-parameters measured on a 2.2–6.5 GHz complementary metal oxide semiconductor (CMOS) PA. Compared to the long-short term memory (LSTM), support vector regression (SVR), and conventional ELM modeling methods, the proposed method performs excellently. For example, the modeling speed is two orders of magnitude faster than SVR and LSTM, and the modeling accuracy is more than one order of magnitude higher than ELM.

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This article presents a wideband bias circuit with low parasitic inductance for high-power pulsed amplifiers. The proposed bias circuit works similarly to the traditional bias circuit in that it can ensure the transmission of microwaves from the power amplifier to the load while preventing the transmission of microwaves from the power amplifier to the power supply. By making the bias line shorter and the transmission line wider than the traditional bias circuit, the proposed bias circuit reduces its parasitic inductance. The reduction of parasitic parameters is critical for reducing the drain voltage overshoot of the high-power pulse power amplifier and ensuring its safety. The simulation results demonstrate that the proposed bias circuit has a lower parasitic inductance and a wider bandwidth. To validate the theory and simulation results, the traditional and the proposed bias circuits are fabricated using microstrip circuits. Both the simulation and experimental results indicate that the proposed bias circuit has a one-third lower parasitic inductance than the traditional bias circuit. Furthermore, the proposed bias circuit has a wider bandwidth.

By increasing the impedance of the microstrip of the combine port, a new Gysel power combiner/divider (PCD) with enhanced average power-handling capability (APHC) was proposed. This article shows the simulated results of the traditional Gysel PCD and the proposed Gysel PCD at the center frequency of 2.4 GHz and 10 GHz. For verification, one example of the proposed Gysel PCD operating at 2.4 GHz was designed, fabricated, and measured. One traditional Gysel PCD operating at 2.4 GHz was also fabricated to compare the APHC of the proposed Gysel PCD and the traditional Gysel PCD, by means of measuring the temperature variation of the microstrip line at the same power. The measurement result suggests the APHC of the proposed Gysel PCD is nearly twice that of the traditional Gysel PCD.