Hybrid harmonic‐intermodulation distortion behavioral model for shortwave power amplifiers

Abstract

In this article, a hybrid harmonic-intermodulation distortion (HHIMD) behavioral model is proposed for imitating the shortwave power amplifier (SWPA) behavioral distortion, that is, harmonic distortion, intermodulation distortion, and memory effect. The proposed model is composed of an intermodulation distortion module, a quadrature digital up-converter module and a harmonic distortion module. To demonstrate the modeling accuracy, the proposed model and measured SWPA are compared in the time domain and spectrum domain. It is shown that the proposed model can imitate the SWPA not only harmonic and intermodulation distortion, but also memory effect. The modeling normalized mean squared error between the HHIMD and measured SWPA output is lower than −44-dB.behavioral modeling, harmonic distortion, shortwave power amplifier

Full-Wave Digital Predistortion Linearization Based on Memory Polynomials for HF Power Amplifiers

“…For instance, in the case of a modulated signal which is fundamental wave comprising two frequencies, f1 and f2, the second harmonics would be 2f1 and 2f2 respectively. Apart from these second harmonics, there exists a sum-frequency component f1+f2, which exhibits the highest energy in proximity to the second harmonics as depicted in formula (12) with an approximate enhancement of 8dB for intermodulation. Figure 14 illustrates a typical predistortion effect, which aligns with formulas ( 12)-( 14) discussed in Section II and simulation results obtained from our algorithm.…”

“…K. Cho et al [10] proposed a multi-stage predistortion linearization circuit that ingeniously integrates second harmonic and difference frequency techniques. The HTBP model, proposed by L. Chen et al [11] and G. Xu et al [12], is based on the Hilbert transform technique. This model applies the Hilbert transform to the fundamental wave signal and utilizes harmonic polynomials to accurately represent intermodulation distortion and harmonic distortion.…”

Study on the Law and Mechanism of the Third-Order Intermodulation False Alarm Effect of the Stepped Frequency Ranging Radar

“…References [4,5] analyzed the adverse effects of the out-of-band EMI on the radar, but did not involve the out-of-band multi-frequency of the IM-EMI components. Xu G M and Liu H analyzed the third-order intermodulation interference signal, generated by the multi-frequency interference signal inside the power amplifier and simulated the signal [6,7]. Aiming at the multi-frequency IM problem of the ship communication system, Li J X established the corresponding mathematical model for the IM problem of the naval communication system [8].…”

Analysis and design of a stacked power amplifier with 196% fractional bandwidth using equivalent circuit model

“…The resistive feedback is easy to design, with the disadvantage of high power loss . Harmonic‐tuned amplifiers operating in high‐efficiency switch‐mode rely deeply on accurate harmonic impedance match, resulting in a limited bandwidth …”

“…1 The resistive feedback is easy to design, with the disadvantage of high power loss. 2 Harmonic-tuned amplifiers operating in high-efficiency switch-mode rely deeply on accurate harmonic impedance match, 3 resulting in a limited bandwidth. 4,5 Stacked structure was firstly introduced to improve output power of PA. 6 With the continuous scaling in semiconductor technologies for a single kind of material, the breakdown voltage of a single device decreases; therefore, the level of the achievable output power is limited.…”