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In this paper, we propose a website to exhibit the traffic information for every 5 minutes at certain places of street measured by three radio frequency identification (RFID) readers for 125 tags installed on two different urban-bus companies and transmit those information via GPRS modem from testing point to control center. Each data can be used to indicate the exact point of traffic condition in...
In this paper, an overview of design requirements and novel approaches for improved performance UHF radio frequency identification (RFID) tags is presented. Two matching techniques, inductively coupled structure and serial stub structure are discussed. Different antenna configurations are proposed, focusing on low-profile, low polarization mismatch and high directivity. Paper substrates, that could...
Based on the structure of left-handed transmission line (LH-TL), a novel phase shifter with higher power capacity is designed here. In the present structure, switches of phase shifters are mounted on fingers of LH-TLs, so the electric current through a single switch is only a fraction of that through the whole phase shifter. As a result, the power capacity of present phase shifter can be greatly improved...
A new method based on artificial neural networks (ANN) for solution of the inverse problem for reconstruction of the complex Bragg gratings, precisely, is proposed. The Runge-Kutta method for calculation of spectrum of the reflection coefficient based on the Riccati equation in a fiber Bragg gratings is used and the application of the multilayer perceptron neural network (MLPNN) in inverse scattering...
A novel type of wideband self-adapting coplanar feeding network is designed and fabricated. Proposed design approach results in the large improving in structure and performance of feeding network, compared with typical design using lambda/4 impedance transformers which has narrow band characteristic. The built 8 times 8 antenna array fed by this network has a wider bandwidth with high gain, low side...
A new concept of a passive waveguide reflection attenuator and a T-junction with a variable ratio of the output powers is reported here. A conductive uniform linear polarization grid of nano thickness is inserted into the standard rectangular waveguide. Rotation of the grid results in a change of the output powers. The measured scattering matrix elements compare well with the computer simulation,...
A 16-GHz CMOS differential Colpitts VCO fabricated with the 0.18 mum 1P6M process is presented. This VCO is composed of a PMOS transistor-pair core circuit and two source follower output buffers. The VCO can operate at 16.5 GHz, and the measured phase noise at 1-MHz offset is -115 dBc/Hz. The power consumption of the VCO core is 12.6 mW. Compared with previous reported works, this VCO has a much higher...
Periodic stepped-impedance ring resonators are devised for implementing rat race couplers with a miniaturized area and arbitrary power division. Design parameters of the proposed rat race coupler include impedance and length ratios of the high-Z and low-Z segments. Realized by the standard microstrip technology, two such couplers are designed and fabricated to have power split ratios 3 dB and 6 dB,...
The experimental demonstration of the insensitivity to losses and size of the composite right/left- handed (CRLH) zeroth order resonator (ZOR) is reported for the first time. The prototypes used for this demonstration are implemented in metal-insulator-metal (MIM) technology, which exhibits simplicity of design, high compactness and immunity to spurious resonances.
A high directivity wideband planar coupler based on multi-section inductive-compensated parallel- coupled lines is proposed. The technique is simply achieved by connecting the optimum inductors at all coupler's ports of parallel-coupled lines. The inductors function as directivity compensating elements. Also, the proposed coupler is excellently matched at all ports. The technique is verified by the...
A 5 GHz Low noise amplifier (LNA) has been implemented in a standard 0.18 um 1P6M Mixed-Mode CMOS process. At 5 GHz, this LNA provides about lOdB gain. Noise figure of LNA is 2.8 dB while drawing 10 mW from a 1.5 V supply. A fully integrated low noise amplifier with technique of source inductive feed-back achieves the goal of low noise and low power dissipation for 5 GHz wireless applications. The...
Transient simulations of GaN MESFETs are performed in which a three-level compensation model is adopted for a semi-insulating buffer-layer, where a shallow donor, a deep donor and a deep acceptor are considered. Quasi-pulsed I-V curves are derived from the transient characteristics, and are compared with steady-state I-V curves. It is shown that so-called current compression is more pronounced when...
This paper describes the design and test results of a high performance low noise amplifier (LNA) for code division multiple access (CDMA) one chip transceiver integrated circuit (IC). The circuits are implemented in a standard 0.35-um Samsung Si/Ge BiCMOS process. The LNA has 4 step forward gain control of 15.8 dB, 4 dB, -7.5 dB, and -21 dB. The measured performance of the proposed LNA at the maximum...
In this paper, an active broadband integrated antenna is presented. The antenna can operate from 900 MHz to 2.3 GHz, with 87.5% bandwidth and over 12 dBi gain. This antenna can directly connect with the differential output of the IC module to provide amplification, radiation and signal combination. Since, there are no more broadband hybrids, the size and the complexity of the unit can be reduced....
We propose a novel dimensionality metric for multi-antenna systems. Being SNR- independent, the metric is suitable for multipath richness comparison of several scenarios having their channel matrices Frobenius-normalized. The metric is based on the equivalence between the given singular values distribution of the normalized channel matrix and those of equi-contribution parallel sub-channels. Under...
An investigation has been carried to get an insight of the operation of a compact ultra wideband (UWB) bandpass filter structure. A circuit model is then proposed for modeling this type of filter. The results of circuit modeling are in good agreements with full-wave electromagnetic (EM) simulations and measurements.
A tunable-filter for a 120-GHz-band receiver MMIC, which is used for a 10-Gbit/s wireless link, was designed and fabricated. The filter can change both the center frequency and bandwidth simultaneously. The filter is a Bessel-type filter and composed of three dual coplanar open stubs and variable-reactance circuits. The filter was monotonically fabricated with InP HEMTs on a single-chip, which occupies...
A novel dual-band CMOS SP4T switch with P1dB of higher than 31 dBm is designed to operate at 0.9 GHz and 1.8 GHz. In the Rx switch path, a carefully designed switched resonator is incorporated in order to block high RF signal power from the power amplifier at the Tx path as well as to maintain low insertion loss in the Rx mode simultaneously. In Tx switch devices, a body substrate tuning technique...
This paper investigates the characteristics of UHF band radio propagation over the Seto Inland Sea in order to obtain primary data to estimate interferences of the terrestrial digital TV system that will be operated in UHF band. The authors have measured UHF band TV broadcasting waves from the Matsuyama station at two observatories in Hiroshima prefecture since June in 2005. From the measurement data,...
In this work, we report, for the first time, a 3.5 V class AB GaAs HBT power amplifier for WiMax/WiBro applications. The amplifier has 3 amplification stages to meet the gain requirement. It is class AB design to achieve both high linearity and efficiency. At 2.35 GHz with Vcc=3.5 V, the amplifier deliveries 25 dBm linear power to the load with 28 dB of gain and 20% of efficiency. Driven by OFDM signal...
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