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Microwave and Wireless Components Letters, IEEE

Issue 11 • Date Nov. 2009

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Displaying Results 1 - 25 of 31
  • Table of contents

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

    Page(s): C2
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  • Efficient Implementation for the Unconditionally Stable 2-D WLP-FDTD Method

    Page(s): 677 - 679
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (152 KB) |  | HTML iconHTML  

    This letter presents an efficient algorithm for the unconditionally stable two-dimensional finite-difference time-domain method with weighted Laguerre polynomials (2-D WLP-FDTD). The huge sparse matrix equation is solved with a factorization-splitting scheme. This leads to much less CPU time and memory storage than those in the conventional implementation. To verify the accuracy and efficiency of the proposed method, two numerical examples are given. View full abstract»

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  • Millimeter Wave Characterization of a Catadioptric Lens for Imaging Applications

    Page(s): 680 - 682
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (636 KB) |  | HTML iconHTML  

    Characterization of a catadioptric dielectric lens-horn configuration for short-range sensing and imaging is presented. The focusing property is investigated both numerically and experimentally at 108 GHz. The lens-horn provides a focal spot of ~ 0.9 lambda at a distance of ~ 4.5 lambda. An imaging example employing the lens in a CW imaging setup is presented. A test pattern was imaged and a marked improvement in image resolution was observed. With the aid of the lens, features close to the wavelength are resolved, which are absent or indistinguishable otherwise. View full abstract»

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  • A Novel Triple-Band Microstrip Branch-Line Coupler With Arbitrary Operating Frequencies

    Page(s): 683 - 685
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB) |  | HTML iconHTML  

    This letter presents a novel microstrip branch-line coupler operating in three frequency bands. The design methodology of the triple-band branch-line coupler is established by using a compensation technique to improve the matching property within each passband region. The proposed coupler with compact size is realized by folded microstrip open-circuited and short-circuited stubs. The measured, full-wave simulated and equivalent-circuit modeled results illustrate good agreement among them, which validates the design method and shows the advantages of deep rejection between each operating frequency, and the dc grounded input and output ports. View full abstract»

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  • Characterization of Average Power Handling Capability of Bandpass Filters Using Planar Half-Wavelength Microstrip Resonators

    Page(s): 686 - 688
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (218 KB) |  | HTML iconHTML  

    Several closed-form equations are obtained for characterizing the average power handling capability (APHC) of bandpass filters (BPFs) using planar half-wavelength open-circuited microstrip resonators. It is found that the temperature rise (TR) of the BPF is the product of two terms corresponding to the single microstrip resonator and the filter, respectively. The APHC of an eighth-order open-loop BPF is determined numerically, with good agreements obtained between its maximum TRs calculated using our model and 3-D-FEM software. View full abstract»

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  • Elliptic-Function CPW Low-Pass Filters Implemented by Means of Open Complementary Split Ring Resonators (OCSRRs)

    Page(s): 689 - 691
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (371 KB) |  | HTML iconHTML  

    In this letter, an elliptic low-pass filter (LPF) implemented in coplanar waveguide (CPW) technology by etching open complementary split ring resonators (OCSRRs) in the central strip is presented for the first time. The OCSRRs behave as series connected parallel resonant tanks, whereas metallic patches etched in the back side of the substrate provide the required shunt capacitance to achieve the elliptic function response. An order-5 elliptic LPF has been designed and fabricated to illustrate the possibilities of this new approach. The measured frequency response is in good agreement with the ideal elliptic function up to twice the cutoff frequency (fc=1& GHz). Since OCSRRs are electrically small resonators, filter dimensions are also small (device length is 2.5 cm, namely 0.13 lambda , where lambda is the guided wavelength at fc). This work is illustrative of the possibilities of OCSRRs for the design of compact planar filters and other microwave components. View full abstract»

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  • Compact UWB Bandpass Filter Based on Signal Interference Techniques

    Page(s): 692 - 694
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (183 KB) |  | HTML iconHTML  

    This letter presents a new type of compact ultra-wideband (UWB) bandpass filter (BPF) based on interference techniques. The structure is formed by a short-ended coupled line coupler connected in parallel to a transmission line. The transmission and reflection zeros of the filter can be controlled through the analytical equations and rules given. To validate the suggested filter scheme, the design, fabrication and measurement of a microstrip UWB BPF is presented. View full abstract»

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  • Harmonic-Suppressed Bandpass Filter Based on Discriminating Coupling

    Page(s): 695 - 697
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (359 KB) |  | HTML iconHTML  

    This letter presents a novel method to suppress harmonic responses of parallel-coupled bandpass filters. The harmonic suppression is based on discriminating coupling. The coupling coefficient at fundamental resonant frequency can be tuned to desirable values whereas it is zero at the second harmonic. Hence, the coupling region blocks the second harmonic but still allows the transmission of signals at passband frequency. Benefiting from this feature, the second harmonic can be suppressed without degrading the passband performance. Furthermore, no additional circuit is needed. For demonstration purpose, two example filters are implemented. The experimental results are presented to verify the proposed method. View full abstract»

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  • Compact Dual-Mode Open Loop Microstrip Resonators and Filters

    Page(s): 698 - 700
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    A novel compact microstrip dual-mode resonator and filter are proposed. The characteristics of the dual mode resonator are investigated. It is found that the filter response exhibits a desirable stopband response where the first spurious passband naturally occurs at 3f0. Finally, methods of miniaturizing such resonators and filters are discussed. The proposed structure was able to achieve 60% size reduction. View full abstract»

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  • Novel Substrate Integrated Waveguide Filters With Mixed Cross Coupling (MCC)

    Page(s): 701 - 703
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    A new type of substrate integrated waveguide filter with mixed cross coupling (MCC) is proposed, with its mechanism of generating extra transmission zeros using MCC investigated. Less mixed coupling is needed to obtain the same number of transmission zeros in comparison with inline filters, with good agreements obtained between the measured and the simulated S-parameters of the developed filters. View full abstract»

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  • An HTS Wideband Filter Using Interdigital-Like Resonators at UHF Band

    Page(s): 704 - 706
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (125 KB) |  | HTML iconHTML  

    A wideband superconducting interdigital-like filter at UHF band has been successfully designed and fabricated. An interdigital-like resonator is proposed to realize both strong coupling and compact size. A ten-pole demonstration high temperature superconducting filter is developed with a center frequency of approximately 340 MHz and a fractional bandwidth of 26%. The measurements show that the insertion loss of the filter is less than 0.2 dB, the return loss is better than 17 dB, and the out-of-band rejection is better than 70 dB. View full abstract»

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  • UHF Band Ultra-Narrowband Superconducting Filter With Double U-Type Secondary Coupling Structure

    Page(s): 707 - 709
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (115 KB) |  | HTML iconHTML  

    A double U-type secondary coupling structure (DUSCS) is used for a compact ultra-narrowband filter in the ultra-high frequency (UHF) band. It can effectively reduce the coupling and thus spacing between coupled twin-spiral resonators. A six-pole superconducting filter at 600 MHz with a fractional bandwidth of 0.083% is designed and fabricated to validate this technique. The filter size is reduced by 15% compared with the filter designed without DUSCSs. View full abstract»

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  • MEMS-Based Tunable LC Bandstop Filter With an Ultra-Wide Continuous Tuning Range

    Page(s): 710 - 712
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (849 KB) |  | HTML iconHTML  

    This letter presents a new microelectromechanical system-based tunable LC filter that utilizes a tunable capacitor and a tunable inductor in a single device. An electrically floating metal plate is located between the tunable capacitor and the tunable inductor. As the floating metal plate is thermally moved and used commonly for both the capacitor and inductor, the device provides an ultra-wide continuous frequency tuning range by a simultaneous increase or decrease of the capacitance and inductance. The fabricated tunable LC filter showed a continuous frequency tuning ratio in excess of 127% in a range of 8.8 GHz to more than 20 GHz. View full abstract»

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  • Deembedding Accuracy for Device Scale and Interconnection Line Parasitics

    Page(s): 713 - 715
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    In this letter, we investigate the deembedding accuracy of open-short (OS) and pad-open-short (POS) deembedding for transistor measurement and modeling. It is found that all of the transistor intrinsic element values except for the gate-resistance, Rg , are independent of the deembedding procedure. Furthermore, the difference in Rg is dependent on the device size. To analyze the origin of the deembedding difference, the equivalent circuits of the PADs and interconnection lines are constructed from the measured data by varying the values of parasitic parameters. View full abstract»

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  • A 2.45/5.2 GHz Image Rejection Mixer With New Dual-Band Active Notch Filter

    Page(s): 716 - 718
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (232 KB) |  | HTML iconHTML  

    A 2.45/5.2 GHz dual-band Gilbert downconversion mixer with image rejection function is presented, which is implemented using the 0.18 mum CMOS technology. The proposed differential dual-band image rejection circuitry is employed for the 2.45/5.2 GHz WLAN application to effectively diminish the DC power consumption and complexity of circuit design compared to the traditional Hartley or Weaver architectures. Moreover, the cross-connected pair consisted of NMOS and PMOS transistors in the proposed notch filter will further ameliorate the image rejection capability. The IC prototype achieves conversion gain of 10.5/11 dB, IIP3 of -4.9/-5.2 dBm for RF = 2.45/5.2 GHz and IF = 500 MHz while the image rejection ratio is better than 36/45 dB in the whole operation bandwidth. View full abstract»

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  • A Weak-Inversion Low-Power Active Mixer for 2.4 GHz ISM Band Applications

    Page(s): 719 - 721
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (532 KB) |  | HTML iconHTML  

    This work describes a fully integrated active mixer designed in 0.18 mum CMOS technology for 2.4 GHz industrial, scientific and medical (ISM) band applications. The mixer uses a source driven local oscillator (LO) to integrate the RF-LO buffering with the active mixer, and weakly inverted input MOSFETs to improve the gain and noise performance. The double-balanced quadrature mixer has a measured conversion gain of 32 dB with a double sideband (DSB) noise figure (NF) of 8.5 dB at 30 MHz intermediate frequency (IF) while consuming only 0.56 mA of current from a 1.8 V supply. View full abstract»

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  • A Low Voltage and Low Power Bottom-Series Coupled Quadrature VCO

    Page(s): 722 - 724
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (820 KB) |  | HTML iconHTML  

    This letter presents a new low power quadrature voltage-controlled oscillator (QVCO), which consists of two complementary cross-coupled voltage-controlled oscillators (VCOs) with split-source tail inductors. The bottom-series coupling transistors are in parallel with the tail inductors and require no DC voltage headroom. The proposed CMOS QVCO has been implemented with the TSMC 0.18 mum CMOS technology and the die area is 0.512 times 1.065 mm2. At the supply voltage of 1.1 V, the total power consumption is 2.545 mW. The free-running frequency of the QVCO is tunable from 4.38 to 4.71 GHz as the tuning voltage is varied from 0.0 V to 0.6 V. The measured phase noise at 1 MHz frequency offset is -120.8 dBc/Hz at the oscillation frequency of 4.4 GHz and the figure of merit (FOM) of the proposed QVCO is -189.61 dBc/Hz. View full abstract»

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  • A 40 GHz Differential Push-Push VCO in 0.18 \mu{\rm m} CMOS for Serial Communication

    Page(s): 725 - 727
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    A 40 GHz differential CMOS push-push VCO is proposed for high-frequency applications. It is shown analytically that the phase noise of the VCO output at the full-rate frequency is close to 6 dB higher than that of the half-rate frequency. The result of the phase noise analysis is verified by simulations and measurements. A phase noise of - 101 dBc/Hz was achieved at 1 MHz offset frequency. The proposed push-push VCO design enables higher VCO frequency operation with differential output, which is suitable for millimeter wave frequency synthesizers. View full abstract»

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  • A DC-21 GHz Low Imbalance Active Balun Using Darlington Cell Technique for High Speed Data Communications

    Page(s): 728 - 730
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (380 KB) |  | HTML iconHTML  

    A DC-21 GHz low imbalance active balun using a 2 mum InGaP/GaAs HBT process is presented in this letter for high speed data communications. A Darlington cell is adopted to enhance 3 dB bandwidth of the proposed active balun. A feedback capacitor is designed to compensate the phase error between differential output ports caused by the different number of stages. The proposed active balun achieves a broad bandwidth of 21 GHz, an average small signal gain of 2.5 dB, a maximum amplitude imbalance of 1.2 dB, and a phase error of less than 5deg. The measured group delays of the balun are lower than 30 ps with low variation. Moreover, an eye diagram with a pseudorandom bit stream of up to 12.5 Gbps is presented. The active balun is appropriate for high speed data communications due to its low imbalance and group delay. View full abstract»

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  • IF Amplifier Section in 90 nm CMOS Technology for SoC Microwave Radiometers

    Page(s): 731 - 733
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (233 KB) |  | HTML iconHTML  

    In this letter a novel design solution in 90 nm CMOS technology is proposed for the IF amplifier, low-pass filter and square-law power detector of a system-on-chip (SoC) microwave radiometer. To minimize the number of off-chip components (just a single capacitor) the IF filter is based on an active gmC configuration, whereas the power detector exploits the MOS transistor non-linearity, i.e., avoiding the need for Schottky diodes. The fabricated IF chip features a sensitivity of 3 mV/nW, a linearity range of about 25 dB around the -60 dBm level, a noise equivalent bandwidth of 58 MHz and a current consumption of only 1.8 mA at 1.2 V supply. The core area is within a rectangle of 220 mum times 540 mum. The proposed design solution is also compatible with SiGe BiCMOS processes and can be regarded as a further step toward the realization of microwave radiometric sensors fully integrated on silicon. View full abstract»

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  • A Wideband Low Noise Amplifier With 4 kV HBM ESD Protection in 65 nm RF CMOS

    Page(s): 734 - 736
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (249 KB) |  | HTML iconHTML  

    This study presents a wideband low noise amplifier (LNA) including electrostatic discharge (ESD) protection circuits using 65 nm CMOS with a gate oxide thickness of only ~ 2 nm. By co-designing the ESD blocks with the core circuit, the LNA shows almost no performance degradation compared to the reference design without ESD. Under a power consumption of only 6.8 mW, the silicon results show that the LNA can achieve a peak power gain of 13.8 dB. Within the 3 dB bandwidth from 2.6 GHz to 6.6 GHz, the noise figure (NF) is in a range of 4.0 dB to 6.5 dB and the input reflection coefficient S 11 is below -13.0 dB. Using the miniaturized Shallow-Trench-Isolation (STI) diode of ~ 40 fF capacitance and a robust gate-driven power clamp configuration, the proposed LNA demonstrates an excellent 4 kV human body mode (HBM) ESD performance, which has the highest voltage/capacitance ratio ( ~ 100 V/fF) among the published results for RF LNA applications. View full abstract»

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  • A 3–10 GHz CMOS UWB Low-Noise Amplifier With ESD Protection Circuits

    Page(s): 737 - 739
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (475 KB) |  | HTML iconHTML  

    A low-power fully integrated low-noise amplifier (LNA) with an on-chip electrostatic-static discharge (ESD) protection circuit for ultra-wide band (UWB) applications is presented. With the use of a common-gate scheme with a gm-boosted technique, a simple input matching network, low noise figure (NF), and low power consumption can be achieved. Through the combination of an input matching network, an ESD clamp circuit has been designed for the proposed LNA circuit to enhance system robustness. The measured results show that the fabricated LNA can be operated over the full UWB bandwidth of 3.0 to 10.35 GHz. The input return loss (S11) and output return loss (S22) are less than -8.3 dB and -9 dB, respectively. The measured power gain (S21) is 11 plusmn1.5 dB, and the measured minimum NF is 3.3 dB at 4 GHz. The dc power dissipation is 7.2 mW from a 1.2 V supply. The chip area, including testing pads, is 1.05 mm times 0.73 mm. View full abstract»

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  • Dedicated Large-Signal GaN HEMT Model for Switching-Mode Circuit Analysis and Design

    Page(s): 740 - 742
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (314 KB) |  | HTML iconHTML  

    A novel large-signal gallium nitride (GaN) high electron mobility transistor (HEMT) model that focuses on and improves analysis and design of switching-mode power amplifiers (PAs) is presented in this letter. The proposed model can be constructed using standard DC and AC characterization measurements and easily implemented in any computer-aided design (CAD) software to simulate and design switching-mode amplifiers. The model can predict the behavior of a switching-mode PA accurately at saturation and, due to the proposed approach, also well in the weak compression region. Using the developed model, an inverse class-F PA is designed and fabricated for validation purposes. The prototype developed using the proposed model achieved power-added efficiency (PAE) of 67% for an output power of 36.7 dBm at 2.35 GHz. Comparison between simulation and measured results of the manufactured PA proves the validity and accuracy of the proposed model. View full abstract»

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  • A Transistor-Based Analog Predistorter With Unequal Delays for Memory Compensation

    Page(s): 743 - 745
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (712 KB) |  | HTML iconHTML  

    A transistor-based analog predistorter (APD) with memory effect compensation is represented. The nonlinearity of a gain amplifier generated by a low supply voltage is used as an error generator. The predistorted signal by the unequal-delayed nonlinear paths improves the linearity by compensating for memory effects of the power amplifier (PA). For verification, the proposed APD with three-branch nonlinear paths is implemented with a 30-W class-AB PA and tested using two-tone and various wideband code division multiple access (WCDMA) signals at 2.14 GHz. From the measured results, the proposed APD significantly improves the linearity of the PA with memory effects. View full abstract»

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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.

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