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Microwave and Wireless Components Letters, IEEE

Issue 12 • Date Dec. 2010

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Displaying Results 1 - 22 of 22
  • Table of contents

    Page(s): C1 - C4
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  • IEEE Microwave and Wireless Components Letters publication information

    Page(s): C2
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  • Transient Behavioral Modeling of Nonlinear I/O Drivers Combining Neural Networks and Equivalent Circuits

    Page(s): 645 - 647
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (268 KB) |  | HTML iconHTML  

    In this letter, a new method for nonlinear behavioral modeling of high-speed I/O drivers is presented, combining neural networks with driver specific circuit knowledge. In the proposed technique, the circuit knowledge of the driver is exploited to preserve the physical property of the driver. In addition, several neural network sub-models are incorporated into the overall model structure to effectively compensate the missing information in the existing buffer models, when dealing with analog input signals of various shapes. The validity and efficiency of the proposed technique are demonstrated through the modeling of a commercial I/O driver and the use of the resulting model for signal integrity simulations. View full abstract»

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  • Acceleration of LOD-FDTD Method Using Fundamental Scheme on Graphics Processor Units

    Page(s): 648 - 650
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (122 KB) |  | HTML iconHTML  

    This letter presents the acceleration of locally one-dimensional finite-difference time-domain (LOD-FDTD) method using fundamental scheme on graphics processor units (GPUs). Compared to the conventional scheme, the fundamental LOD-FDTD (denoted as FLOD-FDTD) scheme has its right-hand sides cast in the simplest form without involving matrix operators. This leads to a substantial reduction in floating-point operations as well as field and coefficient memory access. To reap further advantages of FLOD-FDTD, certain field updates are embedded in the implicit solutions while exploiting the reuse of field data. Using FLOD-FDTD, it is found that significant speed-up is achievable for the method on GPUs. View full abstract»

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  • A Low Dispersion Precise Integration Time Domain Method Based on Wavelet Galerkin Scheme

    Page(s): 651 - 653
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (192 KB) |  | HTML iconHTML  

    To decrease the dispersion error of the precise integration time domain (PITD) method, a new algorithm named the wavelet Galerkin scheme-based PITD (WG-PITD) method is proposed in this letter. The novel method is based on both the wavelet Galerkin scheme and the precise integration technique. The dispersion relation of the WG-PITD method is derived analytically. It is found that the dispersion error of the WG-PITD method is smaller than that of the PITD method, and can be made nearly independent of the time step size. The numerical results confirm the advantages of the WG-PITD method over the PITD method with respect to the memory requirements and the execution time. View full abstract»

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  • Extraction of the Model Parameters for the Attenuation in Printed Transmission Lines

    Page(s): 654 - 656
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (323 KB) |  | HTML iconHTML  

    A method for determining the parameters of the frequency-dependent attenuation model for transmission lines fabricated on printed circuit boards is presented in this letter. The proposed method allows the separate characterization of the conductor and dielectric losses even when the conductor losses present nonideal variation with frequency. Moreover, the steps for implementing a complete model for a transmission line, including the complex propagation constant and characteristic impedance using the extracted data, are also illustrated. Excellent model-experiment correlation for the complex propagation constant for lines fabricated on a printed circuit board technology is achieved up to 110 GHz. View full abstract»

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  • Systematic Modeling and Characterization of a Via-to-SIW Transition

    Page(s): 657 - 659
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (529 KB) |  | HTML iconHTML  

    A model and parameter extraction method for a via-to-SIW transition is presented. The model is derived from an analysis of experimental data and full-wave simulations, allowing to obtain the equivalent circuit parameters for the via including its interaction with the SIW. It is demonstrated through a careful model-experiment correlation that the application of this method allows the correct representation of the via-to-SIW transitions implemented on printed circuit board technology even when changing the structure of the SIW environment. View full abstract»

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  • A Novel Ground Resonator Technique to Reduce Common-Mode Radiation on Slot-Crossing Differential Signals

    Page(s): 660 - 662
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (400 KB) |  | HTML iconHTML  

    By symmetrically placing a pair of open-stub resonators on the slotted reference plane, the radiated emission induced by common-mode noise crossing the slot can be effectively suppressed. The ground resonators provide a shorting path below the slot-crossing differential line for common-mode return current around the resonant frequency and thus avoid the noise to excite the slot line. Based on this idea, test samples with the proposed structure are fabricated on FR4 substrate. The experimental and numerical results show that the radiated emission caused by the slot-crossing common-mode noise can be effectively reduced at least 5 dB in the frequency range from 2.16 to 3.44 GHz by the ground resonators. It is a low cost and effective solution for reducing the common-mode radiation for the slot-crossing high-speed differential signals on high density package or PCB. View full abstract»

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  • A Miniaturized Microstrip Balun Constructed With Two \lambda /8 Coupled Lines and a Redundant Line

    Page(s): 663 - 665
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (696 KB) |  | HTML iconHTML  

    This work presents a miniaturized balun consisting of two re-entrant coupled line sections with ~ λ/8 length connected by a redundant line with ~ 0.04λ length fabricated by planar PCB technology. The structure of the balun was analyzed to obtain the appropriate lengths of couplers and redundant line for the balun realization. An experimental balun operated at -band was designed and fabricated to verify the proposed structure of balun. The prototype demonstrates a miniaturized dimension of ~ 0.29 λ x 0.05 λ and less than 0.36 dB amplitude imbalance associated with 1.6° phase difference in the frequency range of 2.09 3.06 GHz (37.7%). The return loss in the operation band is less than 10 dB. The length of the prototype is almost shrunk to nearly half of the traditional balun. View full abstract»

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  • A Novel Tri-Band Branch-Line Coupler With Three Controllable Operating Frequencies

    Page(s): 666 - 668
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (270 KB) |  | HTML iconHTML  

    A novel branch-line coupler with three controllable operating frequencies is presented for tri-band operation. The tri-band operation is achieved by attaching a matching circuit to each port of the conventional branch-line coupler. Closed-form design equations are derived. For verification, a microstrip 3 dB branch-line coupler operating at 0.9/2/2.45 GHz is designed, fabricated and measured. The measured results are in good agreement with the simulated results. When the return loss and isolation are better than 15 dB and 20 dB simultaneously, the measured bandwidths of three operating bands are all almost 40 MHz, while the amplitude imbalance is below 0.8 dB and the phase difference is within . View full abstract»

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  • Frequency Response Control in Frequency-Tunable Bandstop Filters

    Page(s): 669 - 671
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (197 KB) |  | HTML iconHTML  

    This letter presents a tunable bandstop filter with the capability of controlling the shape of the frequency response. The proposed filter structure can be tuned to have either a Butterworth or a Chebyshev response. The filter can also be tuned to have different center frequencies. Both the frequency response and the center frequency of the filter can be tuned by only adjusting the resonant frequency of each resonator without controlling inter-resonator coupling. Since the proposed filter structure has non-zero inter-resonator coupling, it can find its future application in reconfigurable filters which can be tuned to exhibit either a bandstop or a bandpass response. View full abstract»

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  • A Ka-Band Low Noise Amplifier Using Forward Combining Technique

    Page(s): 672 - 674
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (338 KB) |  | HTML iconHTML  

    This letter presents a wideband low noise amplifier (LNA) implemented in 0.15 μm InGaAs pHEMT technology. The forward combining technique is proposed to boost the amplifier gain at Ka band. Through gain enhancement, the noise characteristic of the amplifier can also be reduced. The Ka-band LNA exhibits a very wide 3 dB bandwidth from 29 to 44 GHz with the power gain of 14.2 dB. The measured noise figure varies between 2.0 and 3.3 dB from 26.5 to 40 GHz. The supply voltage of the circuit is 1.2 V and the power consumption is 38 mW. The overall chip size is 650 μm×720 μm. View full abstract»

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  • LC-VCO Design With Dual- {\rm G} _{\rm m} , Boosted for RF Oscillation and Attenuated for LF Noise

    Page(s): 675 - 677
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (355 KB) |  | HTML iconHTML  

    A VCO topology with a high at RF and low gm at low frequencies (LF) is presented. A high gm(RF) improves start-up conditions, and a low gm(LF) enables a significant improvement of the phase noise and the power supply rejection. The VCO with a modified prescaler was implemented in 0.25 μm CMOS technology. The measured phase is at 1 MH offset, when the VCO works at 3 GHz and consumes 7.5 mW. The corresponding figure of merit is 189.2 dBc/Hz/mW. View full abstract»

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  • A Low Power 77 GHz Low Noise Amplifier With an Area Efficient RF-ESD Protection in 65 nm CMOS

    Page(s): 678 - 680
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (463 KB) |  | HTML iconHTML  

    An area efficient electrostatic discharge (ESD) protection structure is presented to protect the RF input PAD of a 77 GHz low noise amplifier in a 65 nm CMOS process. The results show a measured small signal gain of 10.5 dB at 77 GHz with 37 mW dc power consumption. The measured noise figure at 77 GHz is 7.8 dB. The proposed RF-ESD protection co-design using an inductive cancellation method can handle transmission line pulse ESD currents up to more than 2.7 A without RF performance degradation, which corresponds to an equivalent 4.05 kV voltage level of the human body model. The occupied area by the ESD device is only 0.01 , reducing cost and making it suitable for highly integrated mmW receivers. View full abstract»

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  • An Ultra-Low-Power 24 GHz Low-Noise Amplifier Using 0.13 \mu{\rm m} CMOS Technology

    Page(s): 681 - 683
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (209 KB) |  | HTML iconHTML  

    This study presents an ultra-low-power 24 GHz low-noise amplifier (LNA) using 0.13 μm CMOS technology. We propose of using the minimum noise measure (MMIN) as the guideline to determine the optimal bias and geometry of the transistors in the circuit. The power-constrained simultaneous noise and input matching (PCSNIM) technique is also employed for this design. With the proposed design approach, the LNA achieves a peak gain of 9.2 dB and a minimum NF of 3.7 dB under a supply voltage of 1 V. The associated power consumption is only 2.78 mW. View full abstract»

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  • An Efficiency-Improved Outphasing Power Amplifier Using RF Pulse Modulation

    Page(s): 684 - 686
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (375 KB) |  | HTML iconHTML  

    This letter presents a method for improving the efficiency of an outphasing amplifier by pulse modulating the input signals. By pulse modulating the two input signals to the outphasing amplifier, the outphasing angle can be kept small and hence attain higher efficiency. Whereas, compared to a pulse modulated polar transmitter, the need for high resolution pulsewidth modulation is reduced. To validate the proposed technique, a prototype transmitter system is constructed using commercially available components. Using a CDMA2000 1X signal at 836.5 MHz, the proposed technique achieved a 26% improvement in power-added efficiency compared to a conventional outphasing amplifier at 25.2 dBm output power level while passing the adjacent and alternate channel power ratios for the CDMA2000 standard. View full abstract»

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  • The Layout Geometry Dependence of the Power Cells on Performances and Reliability

    Page(s): 687 - 689
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (474 KB) |  | HTML iconHTML  

    The performances and reliability of the NMOS power cells for power amplifiers (PA) were proposed. The performances of power cells with different layout geometries have been compared. The drain current degradation of the NMOS transistors due to hot-carrier effect and high RF power stresses induced by the load impedance mismatches was also present in this work. The load mismatch factors at fundamental, second-order, and third-order frequencies were analyzed to quantify the power mismatch. The cells were fabricated by a 0.18 μm CMOS process. All of the characteristics of the devices were measured at 5.2 GHz. View full abstract»

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  • 100 GHz Parametric CMOS Frequency Doubler

    Page(s): 690 - 692
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (165 KB) |  | HTML iconHTML  

    A parametric MOS varactor-based integrated frequency doubler is reported. The circuit is implemented in 130 nm CMOS but uses a conservative 0.35 μm gate length and produces an output between 94 and 108 GHz with a minimum measured conversion loss of 14.5 dB and a maximum output power of -7.5 dBm. Slow-wave transmission line filters are employed to reduce circuit loss and the area required by the chip. View full abstract»

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  • A 30 GHz Active Quasi-Circulator With Current-Reuse Technique in 0.18~\mu{\rm m} CMOS Technology

    Page(s): 693 - 695
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (315 KB) |  | HTML iconHTML  

    An active quasi-circulator at 30 GHz is designed and fabricated in TSMC RF mixed signal CMOS technology. The current-reuse technique is integrated with a common-source stage to form the quasi-circulator core while reducing the power consumption at the same time. The transmitter-to-receiver leakage is alleviated by the out-of-phase cancellation of signals from two paths. The isolation and insertion loss between other pairs of ports are improved with buffer stages. All the measured isolations are higher than 12 dB, all the insertion losses are lower than 7.9 dB, and the total power consumption is 15 mW. View full abstract»

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  • A Microwave Method for Accurate and Stable Retrieval of Constitutive Parameters of Low- and Medium-Loss Materials

    Page(s): 696 - 698
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (135 KB) |  | HTML iconHTML  

    A promising microwave non-resonant method has been proposed for accurate constitutive parameter measurement of magnetic materials. The method eliminates the undesired ripples in the extracted parameters by using a medium-loss reference sample and employing one reflection and one transmission measurements. In addition, it is non-iterative and based on point-by-point (frequency-by-frequency) extraction, which is useful for fast constitutive parameter measurement of dispersive materials. It is validated by measurements of a low-loss sample at X-band. View full abstract»

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  • 2010 Index IEEE Microwave and Wireless Components Letters Vol. 20

    Page(s): 699 - 728
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  • IEEE Microwave and Wireless Components Letters information for authors

    Page(s): C3
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Aims & Scope

The IEEE Microwave and Wireless Components Letters (MWCL) publishes three page papers that focus on microwave theory, techniques and applications as they relate to components, devices, circuits, biological effects, and systems involving the generation, modulation, demodulation, control, transmission, and detection of microwave signals.

Full Aims & Scope