Directional modulation (DM) is an emerging technology for securing wireless communications at the physical layer. This promising technology, unlike the conventional key-based cryptographic methods and the key-based physical layer security approaches, locks information signals without any requirements of keys. The locked information can only be fully recovered by the legitimate receiver(s) priory k

In this paper, a novel design of generalized dual-band quadrature hybrid with arbitrary power division ratios is presented and investigated. This coupler has a simple structure and can cover a wide range of power division ratios at the two designated frequencies. Exact closed-form equations are derived based on the even?odd-mode analysis method. The proposed structure offers some special features,

Phase shifters are indispensable microwave components. In this paper, a dual-frequency, passive, analog, and reciprocal phase shifter is proposed, deploying the phase-delay characteristics of complementary split-ring resonator (CSRR). A transmission line is loaded with a pair of CSRR in the ground plane and the phase variations are compared with an ideal transmission line. The proposed phase shift

Continuous wave radars usually use separate transmit and receive antennas that are close to each other. In such a configuration, the antenna crosstalk is the strongest echo acquired by the radar surveillance channel. Sidelobes of the strongest echo are spread over all range cells, limiting the dynamic range of the radar. In this paper, a mismatched filter approach is presented that substitutes cla

In this contribution a dual-band, dual-polarized microstrip antenna element for array applications is presented. The patch antenna is designed to operate simultaneously at around 30 and 20 GHz, the up- and downlink frequencies of modern Ka-band satellite communication systems. The antenna is smaller than half the freespace wavelength at 30 GHz to enable its utilization as array element of dual-ban

A new model is proposed on how to account for the inertia of scatterers in radar-based turbulence intensity retrieval techniques. Rain drop inertial parameters are derived from fundamental physical laws, which are gravity, the buoyancy force, and the drag force. The inertial distance is introduced, which is a typical distance at which a particle obtains the same wind velocity as its surroundings t

This paper presents the design, implementation, and validation tests of a C-band analog-front-end (AFE) for the frequency modulated continuous wave (FMCW) radar. The system was designed to be used in various radar applications, including short rage mode, synthetic aperture radar (SAR) and moving target indication (MTI) mode. The AFE presented here was based on commercial off-the-shelf radio freque