lenses are often used to converge electromagnetic wave namely they convert incident phase front of feed antenna to a flat phase front. together, the lens and the feed create an electrically large aperture antenna. flat lenses provide the cost and weight benefits of the reflect-arrays, while maintaining the advantages of a lens antenna. these lenses use an array of unit-cells which are excited b...

AbstrAct: A scanning-beam antenna on metamaterial coplanar structures is presented. The proposed antenna is, in essence, a composite of Right/Left-Handed (CRLH) coplanar waveguide (CPW) structure incorporating distributed periodic structures with L-C high-pass filter topology which support left-handed (LH) waves. The negative refractive index (NRI) properties of these structures are shown theor...

Millimeter-wave technologies are expected to realize broadband high-speed wireless communication systems for home server and HD video transmission. Multi-layer substrate such as LTCC configuration is well-known to integrate many RF-circuits into small area of the substrate [1]. We have already been developed broadband microstrip-to-waveguide transitions composed of a substrate and metal parts [...

1. Introduction Leaky-wave antennas based on an open-waveguide structure without partly physical cut become a candidate of millimeter-wave antennas because asymmetry of the structure can easily produce a radiation along its length due to a leaky mode. One of these open waveguides for antenna purposes is the stub-loaded ridge-rectangular waveguide, which consists of a ridge-rectangular waveguide...

This communication presents a vertically stacked substrate-integrated waveguide (SIW) antenna array that enables different configurations with the minimum number of SIW layers. achievement lies in modular feature offered by proposed design. Specifically, four distinct can be produced only three designs Depending on layers employed antenna, directivity E-plane is modified. To obtain an equal and...

We demonstrate millimeter-scale optical waveguide grating antennas with unidirectional emission for integrated optical phased arrays. Unidirectional emission eliminates the fundamental problem of blind spots in the element factor of a phased array caused by reflections of antenna radiation within the substrate. Over 90% directionality is demonstrated using a design consisting of two silicon nit...