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Microwave and Millimeter Wave Technology, 2004. ICMMT 4th International Conference on, Proceedings

Date 18-21 Aug. 2004

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Displaying Results 1 - 25 of 272
  • Design of the LTCC tooth-like-slot antenna

    Page(s): 23 - 26
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1942 KB) |  | HTML iconHTML  

    A new type LTCC antenna called tooth-like-slot antenna is proposed and experimentally studied in this paper. The proposed antenna is based on the LTCC technology and has both broad bandwidth and low cross polarization level. A prototype antenna is designed and measured in C band. From the measured data, the impedance bandwidth is about 20%, the cross-polarization level in E plane is about -35dB, and the one in H plane is nearly -22dB. Details of the proposed antenna and experimental results are presented and discussed. View full abstract»

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  • The analysis of cylindrical dipole array for base stations

    Page(s): 239 - 242
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1902 KB) |  | HTML iconHTML  

    A linear dipole array mounted on a finite solid conducting cylinder has potential application in mobile communications. In this paper, the radiation characteristic of this type of antenna array is analyzed using the finite-difference time-domain (FDTD) method. The key features of the FDTD implementation are discussed, with particular emphasis placed upon modeling of the source region and comparison of the convergence character of difference antenna feed models. The technique is used to predict the patterns of the cylindrical dipole array. The FDTD results agree well with the computation results from the method of moments (MOM). View full abstract»

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  • A simple equivalent circuit model CMOS multi-level spiral inductors

    Page(s): 562 - 565
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1918 KB) |  | HTML iconHTML  

    This paper presents a simple structure equivalent circuit model for multi-level spiral inductor on silicon substrates. Skin effect and proximity effect are well modeled by additional RL branch and mutual inductance. For multi-level inductors, since all metal wires couple laterally to each other through the substrate, coupling between wires and between metal layers can be modeled by a parallel combination of resistance and capacitance. Verification with measurement data from a series of multi-level spiral inductors in 2P4M Si process demonstrates accurate performance over wide band frequency range. View full abstract»

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  • Experiments of a thermionic gyro-TWA based on a helical interaction waveguide

    Page(s): 292 - 295
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1913 KB) |  | HTML iconHTML  

    Gyrotron traveling wave amplifier (gyro-TWA) experiments based on a helically corrugated waveguide have been undertaken at Strathclyde University for the last few years. In this paper we report our latest experimental results using a longer pulse electron beam of energy 185keV and current 7.5A produced by a thermionic cathode. The coupling between the second harmonic cyclotron mode of the electron beam and the radiation field occurred in the region of near infinite phase velocity over a broad bandwidth. A saturated gain of 24dB which had a 3dB instantaneous bandwidth from 8.4 to 10.4GHz (i.e. 21% relative bandwidth) was measured. The gyro-TWA had a saturated maximum output power of 220kW, corresponding an electronic efficiency of 16%. Good agreement was found between the measured power and the value predicted from nonlinear beam-wave interaction simulations carried out using the 3D particle-in-cell computer code MAGIC. View full abstract»

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  • Design and analysis of a broad band transimpedance amplifier

    Page(s): 296 - 299
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1962 KB) |  | HTML iconHTML  

    This work presented the design and analysis of a wide-band low noise transimpedance amplifier (TIA) with broader bandwidth for fiber optic communication. Related formulae for the TIA are derived. The circuit is simulated in TSMC 0.25μm process. Additional program is compiled to simulate the circuit gain and phase frequency responses. View full abstract»

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  • Temperature induced substrate effect in monolithic RF active and passive devices on silicon

    Page(s): 566 - 569
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1956 KB) |  | HTML iconHTML  

    In this paper, we demonstrate analyses of the effects of temperature (from -50°C to 200°C) on the power gain performance of RF active devices (MOSFETs and SiGe HBTs) and on the noise figure (NF) performance of RF passive devices (inductors and transformers) for the first time. For RF active devices, it was found that the maximum stable power gain/maximum available power gain (Gms/GAmax) and the square of the short-circuit current gain, (|H21|2) decrease with increasing temperature but show a reverse behavior within a higher frequency range. This phenomenon can be explained by the negative temperature coefficient of the transconductance (gm) and the positive temperature coefficient of the substrate resistance (Rsub). For RF passive devices, it was found that the NF increases with increasing temperature but show a reverse behavior within a higher frequency range. This phenomenon can be explained by the positive temperature coefficients of the metal series resistance (Rs) and the substrate impedance (Zsub). The present analyses are helpful for RF engineers to design less temperature-sensitive RF active and passive devices, and consequently for radio- frequency integrated circuits (RF-ICs). View full abstract»

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  • Performance analysis of a Hough-based TBD algorithm using Pade approximations

    Page(s): 879 - 882
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1908 KB) |  | HTML iconHTML  

    In the background of K-clutter plus thermal noise, the performance of track-before-detect (TBD) algorithm based on Hough transform is analyzed detailed and the analytical expressions of detection probability and false-alarm probability are given. Then the Pade approximation (PA) method is used to approximately calculate these analytical expressions, which avoids complicated integral computation and conveniently finishes evaluating the detection performance. Lastly Monte Carlo simulation shows the feasibility of Pade approximations. View full abstract»

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  • Analysis of oscillator array dynamics for phase-shifterless beam-scanning

    Page(s): 196 - 199
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1959 KB) |  | HTML iconHTML  

    In this paper, set of equations for the oscillator amplitude and phase dynamics are presented by describing the coupled series-resonant oscillator array in term of Z-parameters, and they are simplified for nearest-neighbor coupling topologies. For beam-scanning using, equations of phase dynamics are analyzed under the phase model; the free-running frequencies of oscillators are controlled for certain relations. The usefulness is illustrated through simulations. View full abstract»

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  • Comparison of different calculating methods for path loss in ray-tracing method at 2GHz

    Page(s): 182 - 184
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1889 KB) |  | HTML iconHTML  

    Ray-tracing method is an effective method for wireless propagation predictions. In general there are two methods to calculate the path loss for a given receive point. One is by summing up the individual ray's power; the other is to sum up individual ray's electronic field. In this paper a ray-tracing simulation program is used and the two methods are compared at 2GHz. The simulation results show that the second method more agrees with the measurement results. Then, the properties of the K-factor in the indoor environment are analyzed using this tool. View full abstract»

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  • Performance evaluation of coded M-ary orthogonal modulation

    Page(s): 883 - 886
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1923 KB) |  | HTML iconHTML  

    In this paper, the performances of different coded M-ary orthogonal modulation are simulated and evaluated on the basis of the soft bits output of M-ary orthogonal modulation. The simulation results show that, compared with binary convolutional codes and Turbo codes, nonbinary dual-k codes can be regarded as a tradeoff among bit error rate (BER), computations and decoding time delay, and it can be applied to M-ary orthogonal modulation systems. View full abstract»

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  • Research of a test system for MMW radiometer characterization

    Page(s): 386 - 389
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1907 KB) |  | HTML iconHTML  

    Based on the basic definition of microwave radiometer characterization, a test system for small antenna MMW radiometer characterization is developed. All data acquisition and analysis are automatically realized. The system is applied to test characterizations of an 8 mm Dicke radiometer. Main characterizations (calibration equation, linearity, sensitivity, stability, integration time) of the radiometer are obtained and the results show that the system is highly reliable. View full abstract»

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  • Photonic bandgap properties in stratified media consisting of complex artificial dielectric

    Page(s): 472 - 475
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1935 KB) |  | HTML iconHTML  

    Reflection and transmission coefficients in stratified chiral media are presented for EM oblique plane-wave incidence, based on the 4×4 transfer-matrix method. The photonic band gap properties of one-dimensional layered periodical structures that include of double negative material, so-called backward-wave (BW) material are investigated. The relation between photonic bandgap and chirality admittance has been analyzed. The simulation results show that the width of the PBG in the structure composed of chiral medium and BW medium is larger than that composed of chiral medium and usual medium. Our analysis has shown that the usage of the negative material makes it possible to dramatically widen the band gap of one-dimensional photonic crystal. View full abstract»

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  • Biologic physics character of radio-frequency and its application on tumour therapy

    Page(s): 970 - 973
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1963 KB) |  | HTML iconHTML  

    In this paper, based on the biologic physics characters of radio-frequency, we design a hyperthermia instrument, which uses FPGA to serve as controller and signal generator, utilizes three-electrode capacitive RF hyperthermia to adjust heating field distribution, and realizes multipoint temperature measure by a decaying fluorescence type fiber optical sensor. The therapy result on brain glioma is also presented. View full abstract»

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  • Phase characteristic design of sub-harmonic mixer in a RF direct digital modulation

    Page(s): 300 - 303
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1896 KB) |  | HTML iconHTML  

    A common fourth-harmonic mixer used in RF direct digital modulation is presented in this paper. An important phenomenon has been observed in the mixer that a gentle variance in the LO power or IF power can result in sharp change of the RF signal phase. The effect has not been mentioned before, as well as theoretical explanation. The phase characteristic of an even-harmonic mixer is analyzed and design technique to control the phase characteristic of the mixer is presented. The test results demonstrate the feasibility of the design technique and good performances of the improved circuit. View full abstract»

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  • Effects of RF oscillator phase noise on performance of communication system

    Page(s): 429 - 432
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1943 KB) |  | HTML iconHTML  

    This paper investigates the effects of RF oscillator phase noise on the performance of both single carrier and OFDM system where M-QAM is employed. Phase noise of frequency synthesizer is analyzed by using the classical oscillator phase noise model. This paper analyzes the bit error rate (BER) of both OFDM system and single carrier system. The simulation results of relationship between phase noise bandwidth and BER performance is also presented. View full abstract»

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  • An algorithm on high resolution DOA estimation with unknown number of signal sources

    Page(s): 227 - 230
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1947 KB) |  | HTML iconHTML  

    A new algorithm to estimate the DOAs without knowing the number of signal sources is proposed in this paper. The new algorithm, using the linear prediction (LP) or Pisarenko method in conjunction with adaptive signal parameter, estimation and classification technique (ASPECT) to estimate the DOAs, is with high resolution and no need knowing the number of signal sources. The ASPECT is used to identify the spurious peaks in DOAs and the number of signal sources can be determined at the same time. Through the algorithm, computational complexity can be reduced and the spectrum resolution can be improved also. Computer simulation results approve the correctness and validity of the new algorithm. View full abstract»

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  • Design a reliable LDMOS module for avionic application

    Page(s): 761 - 764
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1973 KB) |  | HTML iconHTML  

    This paper describes a design technique of LDMOS module for avionics and military application. These techniques are particularly oriented in theories and computer aided design. We introduce a practical external matching network design topology to achieve a smaller physical size using microstrip line. The circuit analysis used both transmission line and electromagnetic method (EM) to avoid cover sensitivity effects and achieve equivalently current distribution. A practical LDMOS module was proposed to demonstrate the design module. As the result, the experimental data were in good agreement with the computer simulation data using AWR professional simulation tool. View full abstract»

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  • Adaptive impedance matching in power line communication

    Page(s): 887 - 890
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1914 KB) |  | HTML iconHTML  

    Power line communication is a promising communication method. Yet it is not widely used for the reason of relative high BER (bit error rate) and instability during communication. A primary cause of this poor performance is the time varying characteristics of power line. It leads to the variation in line impedance, and thus the impedance on the interface of communication equipment cannot match with it. So there are heavy attenuation and distortion during signal transfer, and the power cannot be sent out or received completely. In this paper, a new method that performs impedance matching using auto adaptation is presented. It measures the current line impedance, compares it with a typical value, and then selects the proper parameters of matching components to make a good matching. Since it makes a continuous adaptation between power line and communication equipment, the power sent out to the line and received by the receiver is maximized. View full abstract»

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  • The harmonic-balance algorithm to the unified noise analysis of nonlinear microwave circuits

    Page(s): 372 - 376
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1961 KB) |  | HTML iconHTML  

    This paper presented a unified frequency-domain formulation and algorithm for computing noise in the nonlinear microwave circuits. The method uses stationary components and harmonic power spectral density in its formulation to capture time-varying noise statistics. A description of noise spectrum for the interesting ports in the nonlinear microwave circuits is the central results enabling fast and accurate computation. The method is efficient for large circuits with CAD and can generate information useful for noise macromodels. Finally, the experimental results verify its practicability in the application. View full abstract»

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  • Directive metamaterial antenna using high impedance surface

    Page(s): 480 - 482
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1876 KB) |  | HTML iconHTML  

    λ/2 is the minimum length along the propagating direction to support a cavity mode. Here we show experimentally that metamaterial cavity formed by a high impedance surface (HIS) and an electrically responded surface can make a dipole highly directive. 3dB angular width is less than 30°. Thickness of the cavity is much less than λ/4 at working wavelength with return loss up to -40dB. This study is of great potential in realizing subwavelength antenna with high directivity in the future. View full abstract»

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  • Application of Bluetooth technology in ambulatory wireless medical monitoring

    Page(s): 974 - 977
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1918 KB) |  | HTML iconHTML  

    Traditional cable medical monitoring has many shortcomings. Bluetooth is a good solution to resolve those problems is discussed. Then a Bluetooth holter is taken as an example, some important design considerations and experiences are introduced. This example can easily be transplanted to other monitoring and recording fields. View full abstract»

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  • Adaptive radio frequency interference mitigation for HF surface wave radar

    Page(s): 627 - 630
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1944 KB) |  | HTML iconHTML  

    The paper analyses the characteristics of radio frequency interference (RFI) in HF surface wave radar (HFSWR) which adopt the linear frequency modulated interrupted continuous wave (FMICW). RFI will influence all the range cells including all the positive and negative frequency, and that the negative frequency range cells contain only the interference information. Based on the above characteristics, we introduce and analyze a new adaptive interference mitigation beamforming algorithm which using the negative frequency range cells samples to estimate the interference covariance matrix. Experimental results confirm this general and robust algorithm can achieve effective RFI suppression using the data recorded by the HFSWR, located near Zhoushan in Zhejiang China. View full abstract»

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  • An adaptive beamformer in the presence of coherent interference

    Page(s): 185 - 188
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1908 KB) |  | HTML iconHTML  

    Based on eigenspace-based (ESB) method, the paper presents a beamforming algorithm for the uniform linear array which constructs a special matrix instead of the covariance matrix. The algorithm can overcome the problem that ESB method cannot work in the environment of coherent signals. Compared, with the ESB using Toeplitz (TESB) technique, the new algorithm can work well in low SNR and small sample size. Computer simulation results are presented and demonstrate the effectiveness of the proposed method. View full abstract»

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  • A new design method for swept-frequency interferometers

    Page(s): 708 - 710
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1888 KB) |  | HTML iconHTML  

    In this paper a new design method is described for a swept frequency interferometer. A system of diagnosis for plasma electron density has been designed based on the condition Δf · τ = 1. A simulation has been made for the RF circuit. The simulation results validate the analysis of the theory of swept-frequency interferometer system. View full abstract»

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  • Frequency-controllable image rejection down CMOS mixer

    Page(s): 308 - 311
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1974 KB) |  | HTML iconHTML  

    This paper presents a low noise frequency controllable image rejection mixer in heterodyne architecture for 2 GHz applications based on 0.18 μm CMOS technology. The designed mixer uses an inductor and capacitors as a notch filter to suppress the image signal and parasitic capacitance to improve the noise figure (NF) and conversion gain. Two small value capacitors in parallel with an inductor are used for precise tuning the desired image frequency. An image rejection of 20-70 dB is obtained in a 200MHz of bandwidth around 2GHz with IF varying from 100 to 300MHz. The simulation results show single-side band (SSB) NF improved 3.7 dB, the voltage conversion gain of 14.7 dB, unproved by more than 4 dB. The circuit operates at the supply voltage of 1.8V, and dissipates 11.34 mW. View full abstract»

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