2008 NOV 10 - (VerticalNews.com) -- According to recent research published in the journal IEEE Microwave and Wireless Components Letters, "A new 3-D microwave imaging technique is proposed for the detection of a position and size of a spherical object in a dielectric sample located in a waveguide system."

  "The reconstruction is based on a radial basis function neural network inversion, backed by finite difference time domain analysis and requires only elementary measurements of complex reflection and transmission coefficients. Functionality of the technique is illustrated by computational experiments in reconstructing the parameters of a glass sphere and an air bubble in a rectangular Teflon block," wrote A.V. Brovko and colleagues, Technical University ...read more

  2008 NOV 3 - (VerticalNews.com) -- According to recent research from the United States, "An analog RF microelectromechanical systems (MEMS) slotline true-time-delay (TTD) phase shifter is presented for use in conjunction with tapered slot antennas, such as the Vivaldi aerial and the double exponentially tapered slot antenna. The design is a scalable distributed loaded-line cascade of 62 novel differential slow-wave unit cells."

  "Each differential slow-wave unit cell comprises an electrically short slotline section, which is loaded with a shunt impedance consisting of two center-pulled contactless fixed-fixed beam RF MEMS varactors in series, sharing a common electrode. The analog RF MEMS slotline TTD phase shifter is demonstrated on a borosilicate glass wafer using a microfabrication process requiring six masks. It is designed for transistor-transistor logic bias voltage levels and exhibits a measured phase shift of 28.2 degrees/dB (7.8 ps/dB) and 59.2 degrees/cm at 10 GHz, maintaining a 75-Omega differential impedance match (S-11dd < -15.8 dB). The input third-order intercept point is 5 dBm at 10 GHz for a Delta f of 50 kHz, measured in a 100-Omega differential transmission line system," wrote K. Vancaekenberghe and colleagues, University of Michigan ...read more

  2008 NOV 3 - (VerticalNews.com) -- According to recent research from Ankara, Turkey, "This paper presents modeling and analysis of the realization of high-power broadband RF power amplifiers (PAs) and power combiners. In the scope of the study, a model is proposed for a transmission line with a ferrite core, which is the basic building block for the transmission line transformers (TLTs) used in broadband high-power amplifiers and power combiner/divider networks as a building block. ...read more