A novel inverse scattering approach in time domain is presented for reconstructing electrical parameters of a stratified slab. The approach based on the field equivalence principle does not need explicit information of incident fields. Considering a problem equivalent to the original scattering problem inside the region bounded by the measurement points, a cost functional of electrical parameters of the slab is introduced. The minimization of the functional is achieved by a genetic algorithm. Numerical simulations of reconstructing the relative permittivity of a stratified dielectric slab demonstrate the efficacy of the proposed method.
A simple odd number frequency divider with 50% duty cycle is presented. The odd number frequency divider consists of a general odd number counter and the proposed duty cycle trimming circuit. The duty cycle trimming circuit can output 50% duty cycle with only additional six transistors. A prototype divide-by-5 circuit with 50% duty cycle was implemented for a 500-Mb/s ∼ 5.6-Gb/s 1: 10 CDR/DEMUX IC in a 0.13µm 1P8M CMOS process.
Three-dimensional network-on-chip (3D NoC) is a promising method to overcome the bottlenecks in 3D integrated circuit (IC). Although 3D NoC can provide more efficient inter-layer communication with through-silicon vias (TSVs), the low yield and high overhead become the main challenges. To obtain a balance point between cost and performance, the cluster mesh we proposed applies a new vertical interconnects squeezing scheme which decreases the amount of TSV by sharing vertical links through vertical routers. The simulation results show that the proposed topology can improve the yield of chip, reduce the overhead and provide acceptable performance.
Marine shaft power measurement is believed to assess the working condition for marine propulsion system. The traditional equipment uses battery-powered supply but could provide only 2-4 hours continuous monitoring time. To address this issue, a new shaft power measurement technique based on magnetic resonances is proposed in this paper. It was able to transfer 70mA over distances in the range of 5 to 20 millimeters. We experimentally demonstrated efficient power transfer over the self-resonant coils in the transmitter to the receiving end in order to achieve the transfer of energy. It is shown that the strain-type measurement using the magnetic resonances technique produces superior results to those using battery-powered measurements, and thus has application importance.
This work proposes a PWM quadrature phase shifter which uses only two driven switches. The PWM control is based on DC signals asynchronous from the grid, free of PLL and trigonometric calculations, the control can be accomplished with a low-cost micro controller.
A cognitive radio antenna integrated with narrow /ultra-wide band (UWB) antenna is described in this paper. The proposed antenna consists of two port-fed wide-slot antennas sharing the same substrate. The proposed ultra-wideband (UWB) antenna which covers the entire UWB band from 3.1GHz to 10.6GHz is used for channel sensing. The integrated, narrowband wide-slot antenna, operating in the range of 8.2GHz to 11.0GHz is designed to communicate with other wireless devices. The reconfigurable function is realized by utilizing ideal switches. The isolation between the two ports is better than -10dB. The design is suitable for cognitive radio applications where the UWB antenna is required for spectrum sensing and the narrow band antenna is used for reconfigurable operation, which can be tuned over a wide bandwidth by changing the dimensions of the triangular radiation patch using ideal ON/OFF switches.
In this paper, slow wave coplanar waveguide transmission line (SWCPL) is proposed on patterned ground shields in 0.18µm CMOS technology for low-loss passive devices, components and interconnects in millimeter wave region. Patterned grounds act to produce the slow-wave effect and they are usually kept below the metallization plane to reduce dielectric loss of the lossy silicon substrates. The measured attenuation loss and phase constant of the proposed CPW are 0.619dB/mm and 2.574rad/mm, respectively which result in the Quality factor (Q-factor) to be 18 at 54GHz.