Fast Antenna Characterization Improvement by Pattern Rotation

Theoretical Analysis of Polarization Rotation angle in Dual Reflector Antenna

Because of special structure, a dual reflector antenna has beam rotation capability in azimuth and elevation directions. In this structure, the antenna beam can be placed in any point in the space by mechanical movement of twist reflector which it is the most important ability of the antenna. Due to the antenna structure, if the polarization of incident wave is linear, it is expected that the p...

Measurement of Fast Rotation by VLSI Circuits

There exist important problems that require the measurement of very fast motion. Common techniques for motion estimation based on sequences of video images usually fail to deliver the correct results for such problems due to the low video rate. We present an analog VLSI based system that determines the motion in real-time. We demonstrate the performance of that system for the case of measuring ...

Rotation-Invariant Pattern Recognition

In this paper a novel rotation-invariant neural-based pattern recognition system is proposed. The system incorporates a new image preprocessing technique to extract rotationinvariant descriptive patterns from the shapes. The proposed system applies a three phase algorithm on the shape image to extract the rotation-invariant pattern. First, the orientation angle of the shape is calculated using ...

Fast Random Rotation Matrices

In a previous gem Arvo 91] I described a method for generating random rotation matrices based on random unit quaternions. As Ken Shoemake points out in his gem Shoemake 92], that algorithm was awed in that it did not generate uniformly distributed rotation matrices. For a method based on quaternions that corrects this defect, with only slightly more computation, see his algorithm. In this gem I...

Improvement of Heating Pattern of the Coaxial-slot Antenna for Interstitial Microwave Hyperthermia