A novel low-cost beam-steering technique based on the extended-resonance power-dividing method
A novel phased array based on the extended-resonance power-dividing method has been presented. This method eliminates the need for separate power splitter and phase shifters in a conventional phased-array system, resulting in a substantial reduction in circuit complexity and cost. As a proof of principle, a 2-GHz extended-resonance-based phased array using varactor diodes and microstrip patch antennas has been designed, fabricated, and tested. The measured scan range is 20/spl deg/ and the measured efficiency of the extended-resonance phased-array feed is typically 80%, which corresponds to 1 dB of insertion loss.
Low-cost mechanically steered millimeter-wave lens antenna system for indoor LANs
The expected need in the near-future to increase the data rate of personal communication systems up to a few GBit/s, calls for the possibility to explore the millimeter wave part of the electromagnetic spectrum especially for very short range indoor radio links to replace for instance the current Bluetooth or other domestic Personal Area Networks (PANs). High gain antennas in the order of 20 dBi are required to favor the link budget at these frequencies, but the antenna directionality limits user mobility unless at least one antenna in the link can automatically track the other antenna. A new antenna concept that is appropriate for this objective was recently developed by the authors. The objective of this paper is to demonstrate the complete concept by integrating the developed antenna with a simplified RF front-end for data transmission, along with the tracking control system and required algorithms so that a fully operational video transmission can be accomplished with this wireless mm-wave system using low-cost solutions.
Thailand's Muslim Minorities: Assimilation, Secession, or Coexistence?
THAILAND is a predominantly Buddhist country. For most people its very name conjures up images of saffron-robed monks, temple bells, and statues of the Buddha-images that travel brochures or impressions gained during a fleeting visit do little to dispel. Yet a more careful scrutiny of the Thai scene reveals signs of a very different religious tradition existing side-by-side with the Theravada Buddhist establishment. For Thai Islam, its presence indicated equally by the halal foodstall in a crowded Bangkok market or by the silhouette of a minaret against a rural skyline, continues to flourish throughout much of the country. Today an estimated 1,750,000 people, about 4% of the total population, are Muslims, making Islam the second religion of Thailand.' This article briefly outlines the historical background and geographical distribution of Islam in Thailand, drawing particular attention to the ethnic diversity of the various Thai Muslim peoples, before analyzing the nature of contemporary political relationships between the Thai Buddhist establishment and Thailand's Muslim minority. Even though there can be no precise date for the introduction of Islam to Thailand, it is evident that Arab and Persian Muslims en route to