Distributed antenna network (DAN) system has been proposed and various transceiver designs have been proposed to effectively use the distributed antennas. A synchronous assumption was generally used in the previous studies for simplicity. However, the timing offset between users and antennas must be estimated in order to perform coherent detection. In our previous study, we proposed frequency d...

In this study, a hybrid iteration force density method (HIFDM) was proposed to ensure both tension uniformity and accuracy of an antenna mesh reflector. Based on genetic algorithm (GA), the boundary cable reflector net optimized, which further improved precision The static model large deployable structure established using finite element (FEM), thus, iterative strategy for form-finding proposed...

The trend in the conception of future spaceborne radar remote sensing is clearly toward the use of digital beamforming techniques. These systems will comprise multiple digital channels, where the analog-to-digital converter is moved closer to the antenna. This dispenses the need for analog beam steering and by this the used of transmit/receive modules for phase and amplitude control. Digital be...

In this paper, a printed wideband Yagi-Uda antenna with a novel folded dipole driver is proposed. The folded dipole driver is comprised of a folded dipole and a microstrip feedline which functions as an internal balun to mainly determine its wide impedance bandwidth. With the optimized parameters, an operating band of 1.69 GHz ∼ 2.72 GHz can be obtained. Besides the folded dipole driver, the br...

A high performance feed for 11 meters dual shaped reflector system is designed, developed and tested. It is a dual circularly polarized monopulse tracking feed with a measured axial ratio of 0.5dB over the required frequency band of 2GHz to 2.3GHz (Uplink: 2.02GHz -2.12GHz, Downlink: 2.2GHz-2.3GHz). This feed consists of four high performance Teflon dielectric radiating elements. Each dielectri...

Angle-gather migration creates seismic images for different reflection angles at the reflector. We formulate an angle-gather time migration algorithm and study its properties. The algorithm serves as an educational introduction to the angle gather concept. It also looks attractive as a practical alternative to conventional common-offset time migration both for velocity analysis and for AVO/AVA ...