This paper proposes an air-filled substrate integrated waveguide (AFSIW) bandpass filter with a miniaturized non-resonant node (NRN). The NRN structure is introduced between the three resonators, and its size is smaller than the resonator size, which can realize the NRN structure’s miniaturization and reduce the model’s size. The NRN size of this filter is 41% of the NRN size of the existing AFSIW filter. This filter also introduces a transmission zero (TZ) above the passband. The measured results show that the filter’s center frequency is 20.73 GHz, and the bandwidth is 0.86 GHz. The insertion loss in the passband is 0.95 dB, and the return loss is better than 23 dB. Due to the TZ in the upper stopband, the AFSIW filter obtained good selectivity.

This paper presents a design methodology for a broadband high-efficiency power amplifier (PA). The large available impedance space of the extended continuous Class-GF mode is employed. A novel output matching network of the PA consisting of a rectangular double transmission line structure is proposed to meet impedance requirements. To validate the effectiveness of this structure, a high-efficiency PA operating in 0.8–3.0 GHz is designed using a CGH40010F GaN transistor. The measured results demonstrate that the drain efficiency falls within the range of 63.2%–71.9%, the output power varies from 40.2 to 42.2 dBm, and the gain ranges from 9.4 to 11.3 dB within the frequency band of 0.8–3 GHz. The realized PA exhibits an extremely competitive relative bandwidth of 115.8%.

In the contemporary maritime industry, characterised by intense competition, reduced visibility due to heavy fog is a primary cause of accidents, significantly impairing maritime operational efficiency. Consequently, investigating foggy weather navigation safety holds crucial practical significance. This paper, through an analysis and synthesis of various aspects of foggy navigation technology, including foggy navigation regulations at different ports, fog warnings, foggy vessel environmental perception and foggy auxiliary navigation systems, explores the key issues concerning vessel navigation during foggy conditions from a scientific perspective. This discussion encompasses the aspects of regulatory frameworks, standardisation, and the development of intelligent and responsive onboard equipment. Finally, the paper offers a glimpse into potential strategies for fog navigation.

This paper proposes a novel method of applying an iterative generation differential equation method to the multi-component nonlinear signal analysis of a diesel engine. The characteristics of a dynamic model of the single cylinder are analysed and discussed. The iterative generation differential decomposition method decomposes the multi-component signal and extracts multiple single-component signals. The sensitive single-component analysis technology of the complex vibration signal of a diesel engine is formed. The relationship between characteristic parameters of engine vibration dynamics and operation law is derived. A priori information about the unmeasured vibration signals of the roll-on/roll-off (Ro-Ro) passenger ships is not required. The experimental data is validly processed based on this developed method. Results show that this method is practical and feasible in analysing diesel engine vibration signals, especially under different load operating conditions.

Research findings based on the data of current automatic identification systems (AISs) can only be applied to some parts of navigation research owing to their insufficient mining depth. Previously, route planning research has been based on the waypoint and corresponding optimised algorithm without considering the actual navigation situation and sailing habits. The planned route considerably differs from the actual sailing route, and the application result is undesirable. A novel solution to support the route planning problem has been introduced owing to the large accumulation of AIS big data. In this study, the ship navigable route framework (SNRF) which is reflected by real data via mining AIS big data serves as the basic network for the planned maritime route. This study uses the concept of manifold distance based on AIS big data to build a maritime SNRF through high-density searching. It can provide basic theoretical support for actual navigation distance calculation, route planning and route accessibility inspection in the future.