A method is described comprising: transmitting a training signal from each antenna of a base station to each of a plurality of client devices, each of the client devices analyzing each training signal to generate channel characterization data, and transmitting the channel characterization data back to the base station; storing the channel characterization data for each of the plurality of client devices; receiving data to be transmitted to each of the client devices; and precoding the data using the channel characterization data associated with each respective client device to generate precoded data signals for each antenna of the base station; and transmitting the precoded data signals through each antenna of the base station to each respective client device.

System and method for distributed input-distributed output wireless communications

An antenna having at least one main element and a plurality of parasitic elements. At least some of the elements have coupling elements or devices associated with them, the coupling elements or devices being tunable to thereby control the degree of coupling between adjacent elements. Controlling the degree of coupling allows a lobe associated with the antenna to be steered.

Meta-element antenna and array

Aspects of the subject disclosure may include, for example, receiving, by a feed point of a dielectric antenna, electromagnetic waves from a dielectric core coupled to the feed point without an electrical return path, where at least a portion of the dielectric antenna comprises a conductive surface, directing, by the feed point, the electromagnetic waves to a proximal portion of the dielectric antenna, and radiating, via an aperture of the dielectric antenna, a wireless signal responsive to the electromagnetic waves being received at the aperture. Other embodiments are disclosed.

Method and apparatus for coupling an antenna to a device

The basic theory of quasi-optical Gaussian beam propagation and beam transformation by simple optical elements is summarized, and coupling to and between Gaussian beams is briefly discussed Guidelines for Gaussian optics system design are reviewed, the most important being beam truncation and matching Passive components in the terahertz frequency range based on quasi-optical propagation, including polarization processors, filters, diplexers, and ferrite devices, are examined Some active quasi-optical devices, including multielement oscillators, frequency multipliers, and phase shifters, are described Some specific applications of quasi-optical systems are briefly described >

Quasi-optical techniques

A distributed antenna system is provided that frequency shifts the output of one or more microcells to a 60 GHz or higher frequency range for transmission to a set of distributed antennas. The cellular band outputs of these microcell base station devices are used to modulate a 60 GHz (or higher) carrier wave, yielding a group of subcarriers on the 60 GHz carrier wave. This group will then be transmitted in the air via analog microwave RF unit, after which it can be repeated or radiated to the surrounding area. The repeaters amplify the signal and resend it on the air again toward the next repeater. In places where a microcell is required, the 60 GHz signal is shifted in frequency back to its original frequency (e.g., the 1.9 GHz cellular band) and radiated locally to nearby mobile devices.

Remote distributed antenna system

A compact wideband leaky-wave excitation microstrip antenna is provided by a group of microstrip patches disposed on a top region of a dielectric substrate stacked on a conductive ground plane. The top region of the dielectric substrate and the dielectric substrate can be composed of either the same or different dielectric materials. A means for feeding an RF signal, which can be a center feed pin, that normally touches the top conducting patch is electrically isolated from the radiating patches. This arrangement confines the feed current within the probe pin to give an increased input resistance. The compact wideband leaky-wave excitation microstrip antenna permits significant reductions in antenna size, resulting in microstrip antennas with a smaller surface area.

Compact wideband microstrip antenna with leaky-wave excitation

A planar dual band antenna comprising three superimposed dielectric layers, ground plane on one external surface, a conductive patch on the other and parallel conductive strips at the interface of dielectric layers that is closer to the patch. The dielectric constant of the middle layer is different from that of the two other layers.

Planar lower cost multilayer dual-band microstrip antenna

A wideband leaky-wave microstrip antenna having two elongated rectangular nductive patches separated by a gap on a first dielectric material and an elongated rectangular conductive coupling patch on a second dielectric material placed over the gap. The selective placement of the conductive patches and the gap formed thereby permits impedance matching resulting in a leaky-wave propagation mode. Non-radiating modes of propagation are not excited, thereby enhancing the leaky-wave mode of propagation causing radiation. This results in a relatively wide bandwidth of operation that has a main beam that is scannable as a function of frequency. The bandwidth increases substantially as the dielectric constant approaches one. The planar construction contributes to design flexibility and ease of manufacture and has many applications military and commercial communication systems.

Wideband planar leaky-wave microstrip antenna

An electrically small planar tunable microstrip antenna is provided by stacking a radiating element, microstrip dielectric substrate and a ground plane, and coupling the ground plane to a means for tuning. The electrically small, compact, planar tunable microstrip antenna operates at HF and VHF frequencies. The microstrip dielectric substrate is composed of a ferrite or ferrite-ferroelectric composite material having a relative dielectric constant similar to a relative magnetic permeability forming a permittivity to permeability ratio of between about 1:1 and about 1:3. The ground plane is coupled to a means for tuning. In the ferrite-ferroelectric embodiment, the present invention provides an antenna length that is substantially shortened to approximately 1% of the length of a monopole antenna or conventional microstrip antenna with tuning accomplished by a multi-turn coil mechanism. The electrically small planar tunable microstrip antenna provides tuning by varying the ∈ r of the dielectric substrate's ferroelectric material by applying an electric field and by changing the μ r of ferrite material in the dielectric substrate by applying a magnetic field to the ferrite material. This invention also encompasses methods for providing substantial reduction in antenna size at the HF and VHF frequencies with electrically small planar tunable microstrip antennas comprising a dielectric substrate composed of ferrite and ferrite-ferroelectric composite materials.

Planar tunable microstrip antenna for HF and VHF frequencies

A novel circularly polarized (CP) microstrip antenna is introduced. The antenna is fed with a single coaxial probe and the structure is planar. The CP bandwidth is much larger than available single-probe microstrip antennas and the CP radiation quality is excellent over the entire upper hemisphere.

Vahakn Nalbandian

Papers

Compact wideband microstrip antenna with leaky-wave excitation

Planar lower cost multilayer dual-band microstrip antenna

Wideband planar leaky-wave microstrip antenna

Planar tunable microstrip antenna for HF and VHF frequencies

Planar circularly polarized microstrip antenna with a single feed