High-frequency (HF) radars are routinely used for remotely sensing ocean surface currents. However, the performance of the most widely used direction-finding HF radar is degraded due to the effect of the inevitable deviations of actual antenna pattern on the direction of arrival (DOA) estimation. In this paper, we quantify the DOA estimation error resulting from the deviation of the actual ante...

This paper reports a new method for reducing the Radar Cross-Section (RCS) of a metal backed dipole antenna. Numerical simulations are used to show that when the Perfect Electrical Conductor (PEC) is replaced by a carefully designed Frequency Selective Surface (FSS), the electromagnetic performance of the antenna is similar in band, but the RCS of the structure is significantly lower out of ban...

Three-dimensional information of the burden surface in high temperature and excessive dust industrial conditions has been previously hard to obtain. This paper presents a novel microstrip-fed dielectric-filled waveguide antenna element which is resistant to dust and high temperatures. A novel microstrip-to-dielectric-loaded waveguide transition was developed. A cylinder and cuboid composite str...

A W-band dual-polarized Cassegrain antenna for cloud radar is proposed. The aperture diameter of the main reflector of the antenna is 50 cm. By using a modified Magic-T structure in the feed horn, the antenna is dual-polarized with high port isolation. The measured results show that the port isolation is 44.7 dB. The gains are 47.3 dB and 49.5 dB for the two ports at 94GHz, respectively, and th...

A multi-band microstrip patch antenna is developed and presented in this paper. The radiating elements in this antenna are composed of rectangular and triangular slots. These slots are engraved in the rectangular and triangular patch, joined together in one structure, and by single probe feed. The rectangular and triangular slots make the antenna to operate at multiband with relatively high gai...

It is difficult to build directional antennas for borehole radar due to the limited space available in the borehole. Recently published results show, however, that it is possible to obtain directional information even from electrically small antennas. In this paper, we use Finite-Difference Time-Domain (FDTD) modelling to optimise the design of a four-element directional antenna array, so that ...

In this paper, we explore a new resource called multi-target diversity to optimize the performance of multiple input multiple output (MIMO) radar with widely separated antennas for detecting multiple targets. In particular, we allocate antennas of the MIMO radar to probe different targets simultaneously in a flexible manner based on the performance metric of relative entropy. Two antenna alloca...

This article presents the design of rectangular microstrip antenna. The prototype antenna is designed and fabricated on FR4 substrate of dielectric constant Єr = 4.4 and thickness h = 1.66 mm. The proposed antenna is excited using co-axial probe feed. The experimental result of rectangular-shaped microstrip antenna exhibits the excellent radiation characteristic corresponding to impedance bandw...

One of the primary objectives of the fall 1997 intensive observation period (IOP) was to intercompare Ka-band (35 GHz) and W-band (95 GHz) cloud radar observations and verify system calibrations. During September 1997, several cloud radars were deployed at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site, including the full time operation 35-GHz CART millimeterwave cloud ...

In radar and sonar signal processing it is of interest to achieve accurate estimation of signal characteristics. Recorded pulse data have uncertainties due to emitter and receiver noise, and due to digital sampling and quantization in the receiver system. It is therefore important to quantify these effects through theory and experiment in order to construct “smart” pulse processing algorithms w...