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A wideband wide-coverage H-plane horn array with vertical polarization is proposed. Due to its light weight and low profile, the designed array is suitable for applications in spectrum monitoring systems on moving platforms. The switched-beam symmetrical array consists of four identical short H-plane horns. Pattern deterioration occurring in a high-frequency range is solved by inserting two pins in each horn. The measured impedance bandwidth is almost 100% for \VSWR < \2 owing to its fed structure with a thick-cylinder-loaded probe. The measured azimuth-plane beamwidth is about 90 ^\circ over the entire frequency range from 860 to 2500 MHz. Moreover, the measured results with the corresponding simulated results are presented and discussed in this paper. [ABSTRACT FROM PUBLISHER]

Sea surface height can be measured with the delay between reflected and direct global navigation satellite system (GNSS) signals. The arrival time of a feature point, such as the waveform peak, the peak of the derivative waveform, and the fraction of the peak waveform is not the true arrival time of the specular signal; there is a bias between them. This paper aims to analyze and calibrate the bias to improve the accuracy of sea surface height measured by using the reflected signals of GPS CA, Galileo E1b and BeiDou B1I. First, the influencing factors of the delay bias, including the elevation angle, receiver height, wind speed, pseudorandom noise (PRN) code of GPS CA, Galileo E1b and BeiDou B1I, and the down-looking antenna pattern are explored based on the Z-V model. The results show that (1) with increasing elevation angle, receiver height, and wind speed, the delay bias tends to decrease; (2) the impact of the PRN code is uncoupled from the elevation angle, receiver height, and wind speed, so the delay biases of Galileo E1b and BeiDou B1I can be derived from that of GPS CA by multiplication by the constants 0.32 and 0.54, respectively; and (3) the influence of the down-looking antenna pattern on the delay bias is lower than 1 m, which is less than that of other factors; hence, the effect of the down-looking antenna pattern is ignored in this paper. Second, an analytical model and a neural network are proposed based on the assumption that the influence of all factors on the delay bias are uncoupled and coupled, respectively, to calibrate the delay bias. The results of the simulation and experiment show that compared to the meter-level bias before the calibration, the calibrated bias decreases the decimeter level. Based on the fact that the specular points of several satellites are visible to the down-looking antenna, the multi-observation method is proposed to calibrate the bias for the case of unknown wind speed, and the same calibration results can be obtained when the proper combination of satellites is selected. [ABSTRACT FROM AUTHOR]

A wideband microstrip series‐fed magnetic dipole array antenna is proposed. The five‐element dipole array antenna is designed to achieve both wide bandwidth and high gain because of its microstrip series feeding structure. The low‐profile low‐cost array is suitable for applications such as wideband high‐gain wireless communications. Measured and simulated results are in good agreement. The measured impedance bandwidth of the array is enhanced up to 28.6% (5.0–6.7 GHz). The radiation patterns show its advantages of high gain (about 10 dBi), endfire radiation and vertical polarisation. [ABSTRACT FROM AUTHOR]