Abstract:
The present invention provides an antenna-array-based multiple-input multiple-output orthogonal-frequency-division-multiplexing (MIMO-OFDM) system and a pre-coding and feedback method used in the same. The present invention uses QR decompositions of the MIMO channel matrixes to parameterize the channel state information (CSI) of every OFDM frequency band. In addition, the present invention feeds back the information related to θ and φ in the Givens rotation matrixes of the partial frequency bands and then uses an interpolation method to generate θ and φ in the Givens rotation matrixes of all the frequency bands, which further is able to represent the CSI of all the frequency bands. In this way, the present invention has advantages of low complexity and low feedback rate requirement.
Abstract:
A polymer liquid crystal device. The polymer liquid crystal device is fabricated by the following steps. A first substrate is provided, and a coating of a photosensitive composition is formed on the first substrate. Next, a second substrate is disposed on the first substrate. Finally, the coating is completely cured without a mask, forming a polymer dispersed liquid crystal film between the first and second substrate. Furthermore, the coating can also be cured with mask, forming a phase separation composite film between the first and second substrate.
Abstract:
A hybrid beamforming apparatus and method are proposed for a communication system. The hybrid beamforming apparatus includes a plurality of antennas, a plurality of FFT, a plurality of hybrid weight-coefficient generators and a plurality of adders. In each of the hybrid weight-coefficient generators, the weight coefficient for each subcarrier is calculated by a time-domain correlation matrix and a cross-correlation vector, which is calculated by a frequency domain signal and a training signal. The hybrid beamforming apparatus and method according to the present invention can enhance immunity for multipath effect with lower system complexity.
Abstract:
A disc drive includes a housing, a workbench, and a panel. The housing includes an opening, a protection plane, a baffler plane formed on a side of disc ejection and extended from one edge of the protection plane, a support plane extended from the baffler plane, and a flange extended from the support plane. The workbench is installed inside the housing for performing corresponding functions. The panel includes a first fillister corresponding to the support plane and a second fillister corresponding to the flange on the side of disc ejection for covering the opening of the housing. A length of the support plane is approximately equal to a width of the protection plane, and neither the baffler plane nor the support plane include a hole
Abstract:
The present invention describes a prism manufacturing method. According to the method, a semiconductor process method is applied to a wafer for forming a master mold. Then, an electroform process is applied to the master mold for forming a mold. The mold can be used to mass-produce prisms by a well-known manufacturing method.
Abstract:
An LGA connector is used to interconnect an LGA package and a printed circuit board. The LGA connector includes an elastomeric body with a plurality of through-holes. Metal films are formed on inner walls of through-holes and splay out around the mouths of their upper and lower openings. The metal films are formed by vacuum metallization, sputtering, chemical plating, electrical plating or PVD. The through-holes have a funnel-like shape to absorb external stresses and redirect the stress to shrink the through-hole diameters. Moreover, the metal films' elastic deformation is larger than conventional metal conductive fillers so as to improve reliability.
Abstract:
A method for wet etching a metal nitride containing layer overlying a silicon oxide containing layer in a semiconductor device or micro-electro-mechanical device manufacturing process including providing a substrate including a silicon oxide containing layer and an overlying exposed metal nitride containing layer; providing a wet etching solution including phosphoric acid and water; adding a silicon containing compound which undergoes a hydrolysis reaction in the wet etching solution; and, contacting the exposed metal nitride containing layer with the wet etching solution for a period of time to remove the metal nitride containing layer.
Abstract:
An organic layer, such as a porous low-K dielectric in an IC, contains pores open at its surface. To close the pores, the organic layer is contacted by a supercritical fluid that is a solvent for the layer. After a small amount of the surface and the wall of the open pores is solvated, a phase transition of the solvated organic material is effected at the surface to cover it with a dense, smooth, non-porous film that seals the open pores.
Abstract:
A new and improved method for exposing alignment marks on a substrate by locally cutting through a metal or non-metal layer or layers sequentially deposited on the substrate above the alignment marks, using focused ion beam (FIB) technology. In a preferred embodiment, a method for exposing alignment marks on a substrate can be carried out by first providing a substrate that has multiple alignment marks provided thereon and at least one overlying opaque layer, typically but not necessarily metal, deposited on the substrate above the alignment marks. A focused ion beam is then directed against the overlying opaque layer or layers to cut through the layer or layers and expose the alignment marks on the substrate. A noble gas, preferably argon, is typically used as the ion source for the focused ion beam.
Abstract:
A method for determining end-point in a chamber cleaning process is disclosed which can be carried out by first providing a chamber that has a cavity for conducting a semiconductor fabrication process therein, then mounting a crystal sensor on a surface of the chamber cavity at a position that the sensor is exposed to gases or liquids or generated by the fabrication process; conducting a semiconductor fabrication process in the chamber; flowing a cleaning fluid into and in-situ cleaning the surface of the chamber cavity; inputting an oscillating frequency into the crystal sensor and monitoring an output frequency of oscillation from the sensor; and comparing the output frequency of oscillation to an output frequency from a crystal sensor that has a clean surface and determining when the surface of the chamber cavity is cleaned.