42 results about "Symmetric property" patented technology

Antenna systems for handheld wireless communication devices (100) that comprise a first unbalanced feed antenna (112, 718, 802, 1204, 1812) and a second balanced feed antenna dipole antenna (202, 716, 804, 1202, 1802) that are located next to a ground structure (116, 810, 1210, 1824) for the handheld wireless communication devices are provided. The balanced feed dipole antenna and the unbalanced feed antenna exhibit disparate spatial-polarization patterns which are suitable for use with a MIMO transceiver, and the decorrelation of signals received by the two antennas is preserved due to a low level of coupling through the ground structure, which is due, in part, to differences in the symmetry properties of current patterns in the ground structure that are associated with the operation of the two antennas. The two antennas can also be used in a transceiver (629) that uses separate antennas to receive and transmit.

Hidden or overlapped peaks may occur when using SSTDR technology to determine ware faults. These hidden / overlapped peaks may cause false negative determinations (no fault) when testing a wire for faults. In one method of the present invention, the symmetrical property of the SSTDR wave envelope is used to resolve hidden / overlapped peaks. In another method of the present invention, the calibrated normalized loop back SSTDR wave envelope may be used to resolve hidden / overlapped peaks.

A method for routine monitoring and quality assurance of field asymmetry of high energy circular radiation beam producing equipment. The quality assurance process of field symmetry for devices such as stereotactic radiosurgery (SRS) systems is simplified by directly measuring the integration of the half-beam profile. The method of the invention provides that the field symmetry is obtained by positioning the tip of an ion chamber, with a collecting length approximately half the diameter of the beam, at the central axis of the beam, and rotating the ion chamber at varying angular positions, acquiring and comparing readings at desired angular positions. Each pair of readings from positions 180 degrees opposed from each other, are plugged into the equation, Asymmetry=2(R1−R2) / (R1+R2) to compute asymmetry.

Hidden or overlapped peaks may occur when using SSTDR technology to determine ware faults. These hidden / overlapped peaks may cause false negative determinations (no fault) when testing a wire for faults. In one method of the present invention, the symmetrical property of the SSTDR wave envelope is used to resolve hidden / overlapped peaks. In another method of the present invention, the calibrated normalized loop back SSTDR wave envelope may be used to resolve hidden / overlapped peaks.

The invention discloses an on-line detection device with the function of calibrating a systematic error for wave aberration of a projection objective of a photoetching machine, belonging to the field of optical detection. The device comprises an object space mask plate with circular holes, a phase-shifting device, a photoelectric sensor, a memorizer, a controller, an arithmetic unit, a beam splitting device and an image space mask plate, wherein the beam splitting device comprises two binary diffraction gratings: a first grating and a second grating; and the image space mask plate comprises awindow and a first circular hole and a second circular hole with equal diameters. The second grating of the beam splitting device and the second circular hole of the image space mask plate are used as elements for calibrating the systematic error, and the systematic error of the device is calibrated according to the orthogonal property and the odd-even symmetrical property of the Zernike multinomial in a unit circle. The device of the invention is integrated on a masking workpiece platform and a silicon slice workpiece platform of the photoetching machine, and compared with the prior art, thedevice can calibrate the systematic measurement error introduced by a measuring device, thereby increasing the accuracy of measurement.

A semiconductor device including an AND-NOR composite gate of which AND unit is supplied with input signals IN and VDD and NOR unit is supplied with an inverted signal EB of an enable signal E, and an AND-NOR composite gate of which AND unit is supplied with an input signal INB and an enable signal E and NOR unit is supplied with VSS. These gates are inserted into a path to which the input signals IN and INB are supplied. Thereby, a symmetric property of a complimentary signal can be retained. Further, outputs of the AND-NOR composite gates are fixed irrespective of a logical level of the enable signal E. Thus, a sub-threshold current also is inhibited.

The invention discloses a method and device for generating an even-length mirror symmetric sequence. The method comprises the following step: a new even length sequence is obtained by an odd-length centrosymmetric sequence by inserting a code element which is the same as a central code element before or after the central code element, wherein the front half section of the code element and the rear half section of the code element of the new sequence have mirror symmetric property. An even length centrosymmetric sequence set can be generated by using the same method. The length of the new sequence can be selected according to actual application requirement, and the acquired sequence set has autocorrelation with an approximate impulse characteristic and lower cross-correlation. Meanwhile, a sequence group with good anti-frequency-offset property can be obtained by proper selection from the sequence set, and the sequence set can be used in synchronization of a wireless communication system.