Jianfeng Zhai

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The adaptive neuro-fuzzy inference system (ANFIS) has been widely used for modeling different kinds of nonlinear systems including RF power amplifiers (PAs). The modified ANFIS (MANFIS) architecture is simpler than that of ANFIS, but with nearly the same performance for modeling nonlinear systems. In this paper, the MANFIS is applied to model RF PAs with(More)
This paper presents a high-efficiency GaN Doherty power amplifier (PA) with 100-MHz instantaneous bandwidth for 3.5-GHz long-term-evolution (LTE)-advanced application. A modified load modulation network, employing an enlarged peaking amplifier to carrier amplifier power ratio and moderately increased load impedance of the carrier amplifier, is proposed for(More)
In this paper, an extended Hammerstein architecture for dynamic behavioral modeling of GaN power amplifier (PA) is presented. Static strong nonlinearities, long-term linear memory effects and first-order nonlinear dynamics are considered in the model. The parameters of the proposed model are estimated by least square algorithm. For experimental(More)
This paper presents a controllable mode design method for a concurrent dual-mode power amplifier (PA). The principle of the controllable mode combination is proposed by investigating the characteristics of different highly efficient PA modes, which is analyzed from frequency response of the low-pass matching circuit. Then a dual-mode PA with Class-(More)
In this paper, two novel wideband planar power divider/combiners are presented. The first one is based on Y-shaped half mode substrate integrated waveguide (HMSIW) and its wideband performance is obtained by directly matched to tapered microstrip line. The second one is derived from oversized microstrip taper and two-layer four-way power divider/combiner is(More)
The digital predistortion technique is an effective approach for suppressing the intermodulation distortion (IMD) products of high power amplifiers (HPA) in modern mobile communication systems. In this paper, a novel baseband digital predistortion technique based on the complex look-up table (LUT) is presented and experimentally verified. The performance of(More)
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