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Rain‐fed rice (Oryza sativa L.)–wheat (Triticum aestivum L.) (RFRW) rotation can be a resource‐saving solution for sustainable cropping systems. However, conventional puddled and flood transplanted rice, repeat tractor compaction, and years of shallow rotary tillage and paddy–dryland rotation had a negative impact on soil physical in the RFRW rotation (e.g., soil consolidation and shrinkage, shallow tillage layer). A 4‐yr field experiment was established to determine if different post‐paddy tillage systems would improve soil physical properties and plant factors. We compared no‐tillage (NT), conventional rotary tillage (RT), and deep tillage (DT) to improve the deteriorated soil structure, soil water, wheat root system, and grain yield. The results indicated that DT increased the average soil water content by 7.25% and 9.98%, increased field capacity by 9.58 and 5.23%, and decreased the soil bulk density by 6.2 and 2.2% at 0‐to‐20‐cm soil depth in 4 yr as compared to NT and RT, respectively. The NT increased the average relative soil moisture and had higher soil bulk density at 0‐to‐20‐cm depth. The DT deepened the root growth and increased the total root point numbers by 21.0 and 22.8% at 0‐to‐40‐cm soil depth in 4 yr, respectively, compared with NT and RT. In 4 yr, the DT significantly achieved higher average grain yield by 5.3 and 13.5%, respectively, compared with NT and RT. Overall, DT after rice was shown to be a promising management approach for improving wheat yields and might enable sustainable intensification of RFRW rotation. Core Ideas: Traditional puddling destroys the soil structure resulting in hardpan and a shallow tillage layer.Post‐paddy tillage is a tool to improve soil physical properties and plant factors for wheat.Deep tillage improves soil physical properties, wheat roots, and grain yield.Deep tillage is a promising management strategy for sustainable rain‐fed rice–wheat rotation. [ABSTRACT FROM AUTHOR]

In this letter, a novel digital predistortion (DPD) model for broadband power amplifier (PA) linearization is proposed, namely Attention Mechanism based Bidirectional Long Short‐term Memory Network (AM‐BiLSTM) model. In order to verify the linearization performance of the AM‐BiLSTM model in digital predistortion process, a 100 MHz bandwidth 5G new radio (5G NR) signal is employed to test a sub‐6G PA operating at 2.6‐GHz. The experimental results show that the adjacent channel power ratio (ACPR) of the PA with AM‐BiLSTM model can be improved by 24 dB which is 6 dB and 3 dB better than the generalized memory polynomial (GMP) model and the Chebyshev polynomials LSTM (CP‐LSTM) model in ref [1], repspectively. Therefore, the proposed AM‐BiLSTM model is very effective for the DPD linearization of broadband PAs. [ABSTRACT FROM AUTHOR]

Straw incorporation after tillage plays an essential role in soil organic matter and fertility. Despite the importance of understanding the effect of tillage on straw distribution in the soil, an accurate method to measure and evaluate the spatial distribution of straw has not been developed. In this work, we proposed a method for quantifying straw distribution in soil following tillage. The approach uses a straw spatial coordinate digitizer, Pro/Engineer drawing software, and MATLAB visualization software. Straw of four different lengths was mixed into soil by a rotary tillage. Results indicated that the uniformity of straw spatial distribution decreased with the increase of straw length. T50 (50‐mm straw length) had the greatest uniformity. As a result, it is recommended that straw be cut to 50 mm or shorter. This work offers a new insight into the quantitative analysis of straw spatial distribution in soil. Core Ideas: A novel method for measuring and evaluating the straw spatial distribution was developed.The uniformity of straw distribution in multiscale direction was accurately quantified.The accumulation and dispersion of straw in the soil after tillage was visually described.Short straws were more evenly distributed in the soil than long straws. [ABSTRACT FROM AUTHOR]

This letter presents a non‐linear dynamic behaviour model for characterising the broadband power amplifiers (PAs) by using deep convolution generative adversarial networks (DCGAN). The DCGAN structure is based on the convolution neural network model and combines the generative adversarial networks to improve its linearisation ability of the digital predistortion. The DCGAN contains a generation model and a discriminant model. It imports convolution with steps and deconvolution into the structure, respectively, which makes the accuracy of the power amplifier non‐linear model to improve further. For verification, a 5G NR test signal with 100 MHz bandwidth is employed for testing a Doherty RF‐PA that operates at 1800 MHz. The experimental results illustrate that the normalised mean square error value is at least 12 dB higher than the traditional models, and the out‐of‐band suppression of the DCGAN predistorter can be up to 15 dB better than other models. [ABSTRACT FROM AUTHOR]

This letter presents an analogue predistorter (APD) named Schottky diode (SD) and field effect transistor (FET)‐paralleled APD (SDFP‐APD) for the fifth‐generation (5G) mobile system, which is composed of an FET paralleled with two SDs. The simulation results show that the SDFP‐APD has the best compression compensation for the radio frequency power amplifier (RFPA) among the SD‐APD, the FET‐APD and the SDFP‐APD. Furthermore, the measurement results illustrate that the SDFP‐APD can improve the adjacent channel leakage ratio of the RFPA with the best linearisation performance among the three APDs and reduce the error vector magnitude while applying a 100‐MHz bandwidth 5G new radio signal. The proposed SDPF‐APD can be a promising linearisation technique for 5G small‐cell base stations. [ABSTRACT FROM AUTHOR]

A generalised two‐box cascaded Hammerstein‐like (GTBC‐H) digital predistorter is proposed for linearising wide‐band RF power amplifiers (PAs). The GTBC‐H predistorter is composed of a static nonlinearity block for countervailing the strong static nonlinearities and a dynamic nonlinearity block for compensating the memory effects of RF PAs. The proposed predistorter adds extended cross‐terms of the leading terms and some lagging envelope terms in the dynamic nonlinearity block to compensate the memory effects of wide‐band RF PAs more effectively. A 460 MHz and a 1.94 GHz Doherty RF PA are utilised to validate the performance of the proposed predistorter when a three‐carrier wide‐band CDMA and a single‐carrier long‐term evaluation signal are applied separately. The validation results illustrate that the proposed GTBC‐H predistorter can further suppress the residual out‐of‐band emission over the augmented Hammerstein, the enhanced Hammerstein and the parallel‐LUT‐MP‐EMP predistorter. [ABSTRACT FROM AUTHOR]