A delay nonlinear differential equation is proposed to investigate the condition of the microwave chaotic behavior existing between the antenna and the front-end protection circuit of a receiver such as the radar front-end limiter circuit. This investigation concerns the case of intentional or unintentional signals applied to the antenna outside of its bandwidth. Bifurcation diagrams show that ...

Thinned phased array antenna is useful for Radar and satellite communications. Main drawback of phased array antenna is generation of side lobes and grating lobes when the beam is titled from broadside direction toward the end-fire direction. This paper reports the optimization of thinned phased array antenna using genetic algorithm (GA). By varying the tilt angle form broadside direction main ...

A new system-on-a-chip radar sensor for next-generation wearable wireless interface applied to the human health care and safeguard is presented. The system overview is provided and the feasibility study of the radar sensor is presented. In detail, the overall system consists of a radar sensor for detecting the heart and breath rates and a low-power IEEE 802.15.4 ZigBee radio interface, which pr...

In this work, we consider a radar system where the antenna elements are arbitrarily distributed in space with several hundred wavelengths away. We call such a radar system distributed aperture radar system. We assume that the system is operating in multi-pathing environment, such as an urban area. We present methods for designing clutter rejecting waveforms and for reconstruction of reflectivit...

This paper presents a method of imaging a twodimensional section of a walking person using multiple Doppler radar systems. Although each simple radar system consists of only two receivers, different radial speeds allow target positions to be separated and located. The signal received using each antenna is processed employing time–frequency analysis, which separates targets in the time–range– ve...

In the navigational applications, radar and satellite requires a device that is a radar altimeter. The working frequency of this system is 4.2 to 4.3GHz and also requires less weight, low profile, and high gain antennas. The above mentioned application is possible with microstrip antenna as also known as planar antenna. In this paper, the microstrip antennas are designed at 4.3GHz (C-band) in r...

Mesospheric observations were obtained by the EISCAT UHF and VHF radars during the solar proton event of March 1990. We present the ®rst comparison of incoherent-scatter spectral measurements from the middle mesosphere using simultaneous, colocated observations by the two radars. VHF spectra observed with a vertical antenna were found to be signi®cantly narrower than model predictions, in agree...

The Deep Space Network (DSN) [1] was established in 1958 and since then it has evolved into the largest and most sensitive scientific telecommunications and radio navigation network in the world. The purpose of the DSN is to support unpiloted interplanetary spacecraft missions and support radio and radar astronomy observations in the exploration of the solar system and the universe. There are t...

The 440-Mcps conical-scan tracker at the Millstone Hill radar site has been converted to an L-band 12-horn monopulse tracker utilizing a Cassegrain optics reflector system. The amplitude sensing monopulse feed illuminates a 10-foot subreflector and thence an 84-foot-diameter paraboloid with linear or either sense of circular polarization. This system conversion increased the capabilities of the...

RADAR A C-band (5.34 Ghz) multi-parameter radar has been operated in the Okinawa Subtropical Remote Sensing Center, National Institute of Information and Communications Technology (NICT), Japan. It is a full-polarimetric radar with Doppler measurement capability, located on the top of a mountain in the center of the Okinawa Island (128.06oE, 26.59oN, 360m above sea level), southernmost part of ...