Her Majesty the Queen in Right of Canada, As Represented by the Minister

Her Majesty the Queen in Right of Canada As Represented by the Minister of Industry Through the Communications Research Centre Canada

Apisak Ittipiboon

Michel Cuhaci

Aldo Petosa

Jafar Shaker

Rajesh Kumar Mongia

Yahia Mohamed Antar

Kathia L&eacute;vis

Soulideth Thirakoune

Masahiro W Katsube

Dave Roscoe

David Lee

Richard LaRose

Marc Lapierre

Yahia Autar

Matthew Bjorn Oliver

A volume hologram for modifying a characteristic of an input microwave beam and a method for manufacturing thereof are disclosed. The hologram is fabricated from a multi-layer artificial dielectric wherein each layer is made of a dielectric material and includes a lattice of inclusions, for example metal disks disposed on one side thereof, and wherein a pre-determined three-dimensional grating pattern of dielectric perturbations is induced by spatial modulating the lattice of the inclusions. The hologram can be designed for efficiently steering, reshaping, combining or splitting microwave beams.

Volume hologram

An ultra-wideband antenna for operating in a frequency is disclosed wherein a monopole antenna extends from a ground plane. The monopole has an effective length L of one quarter wavelength at the lowest frequency f. A dielectric resonator antenna (DRA) surrounds the monopole antenna for resonating at substantially between or at two and three times the lowest frequency f, the DRA is of a height of less than &#xbe; L and is disposed in such a manner as being above the ground plane and either contacting or spaced therefrom by a gap G, wherein 0&#x2266;G&#x2266;0.2 H. The ultra-wideband antenna is of a much greater bandwidth than the sum of bandwidth of the monople or the DRA alone.

Ultra wideband antenna

The invention relates to an antenna structure for radiating electromagnetic waves in predetermined polarization configurations. A dielectric substrate is provided with a copper conductive pattern printed on each side. The conductors act as scattering elements and are printed for scattering radiation provided along a first predetermined feed direction or alone a second feed direction independently. Preferably, the pattern of the copper is based on an interference pattern and two feeds are used, one to provide radiation along each of the two feed directions. When used as a traveling wave antenna, the resulting structure is flat, having a low profile, and lightweight with simple electronics. Improved isolation Occurs when the printed interference patterns each contain only a component along a single direction such that each scattering element is linear and is parallel to or orthogonal to other scattering elements.

Dual-polarized and circular-polarized antennas

A dielectric loaded microstrip patch antenna is provided for delivering relatively wide operational bandwidth dual-band, with relatively good isolation and flexibility for circular polarization, while having a compact design and lightweight to suit mobile and wireless applications. The microstrip patch antenna has a conducting ground plane and a patch radiator. The patch radiator is spaced from the ground plane by a substantial distance having a first dielectric material therein. A slot feed in the ground plane provides the patch radiator with radio signal energy across the space having the first dielectric material therein. A piece of a second dielectric material is disposed adjacent the slot feed between the patch radiator and the ground plane. The second dielectric material has a dielectric constant that is higher than the dielectric constant of the first dielectric material. The piece of the second dielectric material acts to load the feed in order to improve coupling between the slot and the patch. The piece has a dimension along one of the x and y axes smaller than a dimension of the patch along a same axis. Since the piece is situated between the ground plane and the patch it determines operational characteristics of the microstrip patch antenna.

Dielectric loaded microstrip patch antenna

Due to the frequency dependence of phasing mechanisms applied in planar printed reflectors, when using planar printed reflector antennas beam squint occurs as the frequency is scanned within the operating band. In order to reduce or eliminate beam squint, an incident signal incident upon a reflector is altered in such a way that the outgoing signal retains a same direction. In an embodiment, this is achieved by providing feed elements in different locations, each feed element for feeding a signal of a different frequency. In another embodiment, two reflector arrays are used wherein beam squint caused by the first reflector array is compensated for by the second reflector array.

Techniques for the cancellation of beam squint in planar printed

A dielectric resonator antenna system is disclosed wherein a dielectric material having a high dielectric constant is placed between a dielectric resonator antenna (DRA) and the antenna feed. Preferably the dielectric material having a high dielectric constant is either in the form of an insert within a cavity of the DRA or alternatively is in the form of a thin layer between the feed and the DRA for enhancing coupling therebetween. It is preferred that the high dielectric constant material be at least twice the value of the dielectric resonator antenna.

Broadband nonhomogeneous multi-segmented dielectric resonator antenna

A radiating antenna capable of generating or receiving circularly polarized radiation is disclosed using a single feed and a dielectric resonator. The dielectric resonator has slightly differing dimensions along two axes. Substantially polarized radiation can be generated in each of two mutually orthogonal modes by placement of the probe at each of two locations. When the feed is situated substantially between these two locations, two orthogonal modes are excited simultaneously.

Broadband circularly polarized dielectric resonator antenna

In order to reduce size and facilitate incorporation into planar multi-layer microwave integrated circuits, a microwave hybrid, specifically a Magic-Tee, is formed using microstrip circuit elements and aperture coupling. The Magic-Tee comprises a ground plane interposed between dielectric printed circuit boards. The outermost surface of one of the boards carries a Tee circuit comprising microstrip branch arm conductors with a microstrip conductor projecting transversely from its middle, the Tee junction, to form the leg of the Tee. The outermost surface of the other board comprises a line in the form of a microstrip conductor. An aperture is provided in the ground plane at a position between the Tee junction and an underlying part of the line conductor. Various Tee junction configurations, such as Y or .DELTA., may be implemented also. The magic Tee may be an integral part of an MIC or MMIC device.

Growing community of inventors

Kanata, Canada

Apisak Ittipiboon