In this paper, we reviewed some of the microelectromechanical system (MEMS) research efforts for high frequency applications. The efforts can be generally divided into two areas: planar reconfigurable transceivers and phased arrays using MEMS devices. For the planar transceivers, the interest is in demonstration of RF MEMS devices with a focus on integration issues including architectures and f...

The embedded ultrasonic structural radar (EUSR) was developed based on phased array technology. It can interrogate large structural areas from a single location using ultrasonic guided Lamb and Rayleigh waves generated by tuned piezoelectric wafer active sensors (PWAS) that are permanently attached to the structure. This paper brings together several aspects of the implementation and applicatio...

An aperture composed of multiple small apertures has several advantages over a large continuous aperture when practical issues are included in the analysis. For example, a single bullet can easily produce a catastrophic failure of the laser communication link if all the optical gain for the transmitter (or receiver) is derived from a single large-diameter telescope. In addition to battlefield c...

In this Letter, we demonstrate an 8×8 apodized silicon photonic phased array where the emission from each of 64 nanoantennas was tailored to exhibit Gaussian-shaped intensity distributions in the near field so that the sidelobes of the generated far-field optical beam were suppressed compared to that of a uniform phased array. With the aid of the 72 thermo-optic phase tuners directly integrated...

A space platform for optical communications could benefit from nonmechanical beam steering in which no inertia is used to redirect the laser communications link. This benefit is to come in the form of compact, low-power, lightweight optical phased arrays that provide greater flexibility in their steering capability. Non-mechanical beam steering eliminates the need for massive optomechanical com...

In reconfigurable phased array radars beamforming is performed in the digital domain. Digital implementation can be carried out using finite precision and infinite precision representation of the phased array signal. We consider finite precision representation, since it takes considerably less implementation resources compared with the infinite case. In this paper we analyze quantization effect...

PURPOSE To devise a practical technique for high-resolution evaluation of the anterior optic apparatus using a phased-array surface coil system, and to evaluate this system in patients with suspected optic pathway abnormalities. METHODS A four-element phased-array coil pair was placed on each side of the head, and signal-to-noise measurements were obtained using a head phantom. Comparison bet...

Realizing robust and stable two-way links between the mobile users and the satellite is an extremely challenging RF/Microwave engineering problem. Low cost and low pro le phased array is considered as the best solution for this problem. High performance low cost and miniaturized variable phase shifter is a key enabling technology for such complex smart phased array antenna system. This thesis a...

A four-channel phased array consisting of one surface coil, two endorectal coils, and one flexible endourethral loop coil was designed for MRI of the canine prostate. The endorectal coils provide high signal in the posterior region of the prostate, while the endourethral and surface coils are sensitive to the central and anterior regions of the prostate. Gel phantom experiments indicate that th...

Tunable optical true-time-delay modules based on highly dispersive photonic crystal fibers were demonstrated to provide continuous radio frequency squint-free beam scanning for X-band phased array antenna systems. © 2006 Optical Society of America OCIS codes: (060.2310) Fiber Optics; (280.5110) Phased-Array Radar