This article proposes the design, simulation, fabrication and testing of a beam steerable antenna array using 4 × Butler Matrix feed network technique. The proposed is developed to operate at X band frequency range. integrated operating 10 GHz has bandwidth approximately 2 with an achieved gain 12 dBi. main pattern switched between four directions (+10°, −38°, +38°, −10°) providing effective co...

—This paper proposes a new digital beamformer for uniform concentric spherical array (UCSA) having nearly frequency invariant (FI) characteristics. The basic principle is to transform the received signals to the phase mode and remove the frequency dependency of the individual phase mode through the use of a digital beamforming network. It is shown that the far field pattern of the array is dete...

In this paper, a kind of on-board liquid hydrogen (LH2) cold energy utilization system for heavy-duty fuel cell hybrid truck is proposed. Through system, the LH2 used cooling inlet air compressor and coolant accessories sequentially, to reduce parasitic power, including compressor, water pump, radiator fan power. To estimate ratio power saving capabilities model based on AMESim software was est...

Thermostatic radiator valves (TRV) have proved their significant contribution in energy savings for several years. However, at low heat demand conditions, an unstable oscillatory behavior is usually observed and well known for these devices. This closed-loop instability is due to the nonlinear dynamics of the radiator which result in a large time constant and a large gain for the radiator at sm...

The purpose of this study was to use computational fluid dynamics software Fluent, the numerical simulation to discuss the impact pressure within the flow channel device for flat radiator fan heat flow characteristics. Piezoelectric fan was placed in front of the flow channel, and the cold air flow was introduced to the radiator cooling fan, and thus generated vortex fluid in the flow path arou...

Some new focusing properties of time-domain ultra wide band (UWB) focusing array antennas are presented. The large current radiator (LCR) is considered as the UWB antenna element. Each LCR is replaced by a set of infinitesimal dipoles modeling both the near field and the far field patterns of the antenna element, as well as the coupling between the elements. Several antenna arrays with differen...