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In this letter, a method for designing a Doherty power amplifier (DPA) using bare die and bonding wires (BWs) is proposed. This method adjusts the geometric parameters of BWs to achieve the desired transmission characteristics, allowing BWs to actively participate in the formation of the matching network, thus realizing the codesigning of the DPA and BWs. By designing appropriate BWs compensation to mitigate the intrinsic parasitics of bare die, the inherent obstacles caused by transistor parasitic effects are mitigated. This strategy offers a distinct advantage in terms of concurrently adjusting the target load impedance and phase, leading to a streamlined DPA design process. At the same time, the nonclipping impedance region is expanded, which attenuates the nonlinear effects of parasitic effects. On the basis of the proposed methodology, a DPA operating at 3–4 GHz is designed. Measured results show that the DPA achieves a saturation output power of 42.4–43.6 dBm in the operating band, accompanied by a drain efficiency of 55%–66%, while achieving 42%–54% at 6 dB output back‐off level. [ABSTRACT FROM AUTHOR]

It is well known that accurate estimation of the loop delay between the input and output feedback signals is the key to behavioral modeling and digital predistortion of power amplifier. Nevertheless, most of the traditional loop‐delay compensation algorithms have the disadvantage of high computational complexity. For the purpose of solving this problem, a loop‐delay estimation algorithm based on sliding window has been proposed in this paper, where the first derivative characteristic of the signal is employed to evaluate the correlation between the input and output feedback signals. The simulation and experiment are carried out with different bandwidth signals in this paper. The results show that the proposed algorithm and the traditional cross‐correlation‐based method could align the input and output feedback signals successfully. But in terms of resource consumption, the proposed algorithm could reduce the multiplier nearly by 100% and the adder by approximately 93.2%. [ABSTRACT FROM AUTHOR]

An optimal balance between high efficiency and high linearity is one of the main performance metrics of modern base stations to handle the deep compression of the power amplifier (PA) module. In principle, the plethora of amplitude‐to‐amplitude (AM‐AM) and amplitude‐to‐phase (AM‐PM) distortions are issues worth exploring. Therefore, this paper presents a linearized harmonic‐tuned PA that operates at 2.4 GHz. The presented PA utilizes a compact input matching network (IMN) and output MN (OMN) with shunt‐connected tunable resonant circuits augmented by the stabilization network, whose presence greatly reduces the transistor parasitics and high‐order effects. Hence, a joint embodiment of each other gives optimal fundamental impedance matching alongside harmonic terminations and precise AM/PM waveform properties. The measurement results have shown that the fabricated PA exhibits peak saturated output power of 40.9 dBm and peak drain efficiency (DE) of 67%. In addition, the AM‐AM and AM‐PM curves under continuous‐wave excitation yield a gain flatness of 0.5 dB over a 37.5 dBm power range and ±3.5° phase distortion, respectively, when the input power level is swept up to the saturation level of 40 dBm. When driven with a 5 MHz 64‐QAM OFDM signal and 6.9 dB power back‐off, the manufactured PA meets the adjacent channel leakage ratio specification of −30 dBc at an average output power of 34.5 dBm. [ABSTRACT FROM AUTHOR]

This paper presents a broadband linearizer based on equivalent power‐dependent impedance function (PDIF) of diode and load match network (LMN). A method to measure the PDIF is proposed, then the broadband LMN can be synthesized by using the PDIF and the transfer characteristic of the amplifier to realize a broadband linearizer. To verify the proposed method, a linearizer for a 100 W traveling wave tube amplifier (TWTA) is designed and measured from 29 to 31 GHz. By using the linearizer, the output 1‐dB compression point (OP1dB) has increased by more than 1.2 dB, and phase error has reduced by more than 16.9°. Then a two‐tone signal with 100 MHz spacing is used for test, the results show that 12.2 to 14.6 dB suppression of third‐order intermodulation distortion (IMD3) is achieved over the working frequency range without bias tuning. [ABSTRACT FROM AUTHOR]

In this article, a novel method to design broadband linear power amplifier (BL‐PA) is presented. By adding the image parts for harmonics and intermodulation products (HIMPs), a suboptimal solution of efficiency and linearity in continuous frequencies can be achieved at a broadband to improve the efficiency and linearity performance of the BL‐PA. For verification, a BL‐PA operating 3.2‐3.8GHz is designed and the performances are assessed in multi modes. [ABSTRACT FROM AUTHOR]

In this article, a novel design method of multiband bandpass filters (BPFs) which have flexibly tunable center frequencies is presented by using T-shaped stub-loaded step-impedance resonators (SLSIRs)' multimode characteristics. By controlling the impedance ratios and the length ratios of the T-shaped open stubs, the center frequencies of a multiband BPF can be decided. To verify the effectiveness of the proposed method, a 1.34/2.2/3.3/4.5 GHz quad-band filter using split-ring based on SLSIRs is designed, fabricated, and measured. The proposed filter is composed of a pair of tri-section T-shaped open stubs transmission lines, which form a folded split-ring. By controlling the impedance ratios, the length ratios of the open stubs and the width of the gap of the folded split resonance loop, the quad-band center frequencies are flexibly tunable. Owing to the 0° feed structure, seven transmission zeros can be realized near the pass-band for enhancing the selectivity. The measured results show good agreement with the theory and the EM simulation. [ABSTRACT FROM AUTHOR]

ABSTRACT In this letter, an architecture is presented to solve problems of classical concurrent dual-band Doherty power amplifiers (DPAs) and its design procedure is given. It is a codesign of two single-band DPAs and four filters. Two of filters at the output port are used for impedance transformation, harmonic components suppressing and signal isolating, while the another two split concurrent dual-band signals at the input port. In this way, intermodulation components of the two bands can be effectively suppressed and each band can achieve a good performance as single-band one's. This design concept is demonstrated through implementing of a practical dual-band DPA operating at 1.8 and 2.5 GHz. Measurement results show that efficiencies are 65.0 and 56.3% at the 6 dB output power back-off for concurrent application. The intermodulation components and harmonic components are lower than −40 dB except second harmonic component at 1.8 GHz (−32 dB). © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:530-533, 2017 [ABSTRACT FROM AUTHOR]

This article presents the full design methodology and implementation of inverse Class-F power amplifier with a commercial high-power GaN HEMT. For a 3.48 GHz continuous wave signal, the measurement results show state-of-the-art power-added-efficiency (PAE) of 76.7%, drain efficiency of 81.1%, gain of 12.9 dB, and output power of 39.9 dBm. Within a bandwidth of 200 MHz, drain efficiency and output power are maintained above 60% and 38.5 dBm, respectively. With digital predistortion, it achieves −45 dBc of adjacent channel leakage ratio for a 2.5 MHz wideband signal with a peak-to-average power ratio of 8.9 dB, with an average PAE of 36.7%. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:521-525, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26577 [ABSTRACT FROM AUTHOR]