Wideband digital predistortion of solid-state radar amplifiers

Dunn, Zachary; Yeary, Mark; Fulton, Caleb; Goodman, Nathan A.

doi:10.1109/taes.2016.150142

Cited by 19 publications

(10 citation statements)

References 35 publications

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“…This made it impossible to analyze changes, in the signal during operation caused by widely understood memory effects at the stage of amplifier design. Moreover, optimization of amplifiers' parameters (e.g., ACPR) generally was based on the appropriate selection of load impedance, during load-pull measurements, in order to determine its value for which the optimized parameters reach a satisfactory range [15,[32][33][34]. This approach is unenforceable in case of An appropriate use of the Envelope simulation [31] together with the large-signal electro-thermal model allows for simulating and modeling of amplifier's transmittance changes.…”

Section: Measurement Setup and Amplifier Modellingmentioning

confidence: 99%

A GaN HEMT Amplifier Design for Phased Array Radars and 5G New Radios

2020

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Power amplifiers applied in modern active electronically scanned array (AESA) radars and 5G radios should have similar features, especially in terms of phase distortion, which dramatically affects the spectral regrowth and, moreover, they are difficult to be compensated by predistortion algorithms. This paper presents a GaN-based power amplifier design with a reduced level of transmittance distortions, varying in time, without significantly worsening other key features such as output power, efficiency and gain. The test amplifier with GaN-on-Si high electron mobility transistors (HEMT) NPT2018 from MACOM provides more than 17 W of output power at the 62% PAE over a 1.0 GHz to 1.1 GHz frequency range. By applying a proposed design approach, it was possible to decrease phase changes on test pulses from 0.5° to 0.2° and amplitude variation from 0.8 dB to 0.2 dB during the pulse width of 40 µs and 40% duty cycle.

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Section: Measurement Setup and Amplifier Modellingmentioning

confidence: 99%

A GaN HEMT Amplifier Design for Phased Array Radars and 5G New Radios

2020

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“…The nonlinear behavior of the amplifier introduces distortion in the output pulse. Dunn et al used the digital pre-distortion technique to minimize the distortion of amplified signals that appear to be linearly amplified [20][21][22][23]. With the linear assumption on the amplifier in the WPPAR system, this paper focuses on the frequency response of the antenna systems.…”

Section: Theoretical Formulation Of Biasmentioning

confidence: 99%

“…However, the frequency-dependent power amplifier (PA) and antenna system distort the output waveform in the WPPAR [18,19]. To circumvent the problem from PA, some digital pre-distortion schemes have been explored in [20][21][22][23]. Another challenge is from the transmitting/receiving antenna.…”

Section: Introductionmentioning

confidence: 99%

Bias Correction to Antenna Frequency Response for Wideband Polarimetric Phased Array Radar

Wang

Pang

et al. 2019

Electronics

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The frequency response of wideband polarimetric phased array radar antenna biases polarization measurement. A bias correction method named the iterative frequency division (IFD) algorithm is proposed in this paper to eliminate the effect of frequency response of the antenna system. The method is built on a new measurement bias model in which the effects of frequency response on the backscattering covariance matrix are analyzed. To demonstrate the effectiveness of the proposed method, a wideband microstrip patch array element is designed. Simulation results show that the biases of differential reflectivity ( Z D R ) and linear depolarization ratio ( L D R ) can be decreased to less than 0.1 dB and − 40 dB even for wide beam direction. The proposed method maintains a favorable polarization measurement accuracy for wideband polarimetric phased array radar.

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“…When the MPA is operating in saturation, the output signal bandwidth can be expanded to three to five times the input signal bandwidth. Thus, it is a severe challenge for the analog‐to‐digital converter (ADC) to capture the output signal accurately in the DPD feedback loop 1,2 …”

Section: Introductionmentioning

confidence: 99%

Theory and experiments of a low sampling frequency broadband digital predistortion with cyclostationarity

Lan

Wang

et al. 2020

Satell Commun Network

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To reduce the sampling rate from analog to digital converter for the feedback loop of digital predistortion (DPD) in a microwave power amplifier (MPA), a model was proposed and used to obtain the formulae for the cyclostationarity of the digital modulation signal, which shows that the nonlinear parameter of the MPA model is only determined by the correlation matrix of the signal and can be estimated with the under-sampled output signal. The output signal of the MPA, similar to a high sampling rate, can be recovered by combining the nonlinear parameter with the input signal. Then the DPD of the MPA is implemented through indirect learning architecture to realize its linearization. A Ka-band traveling wave tube amplifier is used to the circuit for performing a low sampling rate DPD process to validate the rationality of the proposed model and formulae.

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Wideband digital predistortion of solid-state radar amplifiers

Cited by 19 publications

References 35 publications

A GaN HEMT Amplifier Design for Phased Array Radars and 5G New Radios

A GaN HEMT Amplifier Design for Phased Array Radars and 5G New Radios

Bias Correction to Antenna Frequency Response for Wideband Polarimetric Phased Array Radar

Theory and experiments of a low sampling frequency broadband digital predistortion with cyclostationarity

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