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Microwave and Wireless Components Letters, IEEE

Issue 5 • Date May 2005

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Displaying Results 1 - 25 of 35
  • Table of contents

    Publication Year: 2005 , Page(s): c1 - c4
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    Freely Available from IEEE
  • IEEE Microwave and Wireless Components Letters publication information

    Publication Year: 2005 , Page(s): c2
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  • Uni-travelling-carrier photodiode performance with X-band modulation at high optical power

    Publication Year: 2005 , Page(s): 297 - 299
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (184 KB) |  | HTML iconHTML  

    We have fabricated and characterized backside illuminated uni-travelling-carrier photodiodes (UTC-PDs) and obtained average photocurrents exceeding 140mA and very high peak-to-peak voltages of 7.4V over 50Ω at 10Gb/s with no indication of reduced bandwidth. Nonlinear distortion at 10 GHz are also measured for high photocurrents, up to 140mA, while retaining third-order intercept point above 30dBm. View full abstract»

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  • Quasi-optical 150-GHz power combining oscillator

    Publication Year: 2005 , Page(s): 300 - 302
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (416 KB) |  | HTML iconHTML  

    A quasi-optical power combiner for a five-element in-line oscillator array is experimentally investigated at 150 GHz. The combiner consists of a periodic dielectric phase grating (hologram) which transforms the near-field of a rectangular horn antenna array into a pseudo-plane wave. The horn array is excited by IMPATT oscillators operating uniformly in both amplitude and phase. A dual offset reflector set-up transforms the pseudo-plane wave to a Gaussian beam which matches the field pattern of a dual mode receiving antenna. Even though an inter-element spacing of 9.5 λ has been chosen, the passive structure gives a power combining efficiency of 74.1%. The power combining oscillator has been operated in both free-running and injection-locked mode. A CW output power of 78.0 mW and 83.5 mW was measured for the free-running and injection-locked oscillator, respectively, which is corresponding to a power combining efficiency of 66.5% and 71.2%, respectively. View full abstract»

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  • A fully integrated 10-Gb/s tapped delay Hilbert transformer for optical single sideband

    Publication Year: 2005 , Page(s): 303 - 305
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (432 KB) |  | HTML iconHTML  

    A 10-Gb/s SiGe HBT tapped delay Hilbert transformer (HT) integrated circuit (IC) is described. The four tap filter uses an integrated LC transmission line with a total delay of 180ps, and the HT has a nominal group delay of 120ps. The circuit is fabricated in a 47-GHz fT SiGe HBT process and consumes 112mW from a -3.3-V supply. Measured s-parameters and time domain waveforms are shown to agree with theory. Measurements of a 10-Gb/s optical single sideband system indicate that 7dB of broadband sideband suppression is obtainable using the IC. View full abstract»

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  • Study of electromagnetic wave propagation through dielectric slab doped randomly with thin metallic wires using finite element method

    Publication Year: 2005 , Page(s): 306 - 308
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (288 KB) |  | HTML iconHTML  

    A new numerical simulation method using the finite element methodology (FEM) is presented to study electromagnetic propagation through a dielectric material slab doped randomly with thin and short metallic wires. The FEM approach described in many standard text books and published papers, is appropriately modified to account for the presence of thin and short metallic wires. Using this modified FEM approach, the transmission and reflection characteristics of a material slab (homogeneous dielectric slab doped randomly with thin and short metallic wires) placed in an X-band rectangular waveguide are estimated. The estimated results are compared with the numerical results obtained using the CST microwave studio simulation tool. View full abstract»

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  • Wide-band RF photonic second order vector sum phase-shifter

    Publication Year: 2005 , Page(s): 309 - 311
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (288 KB) |  | HTML iconHTML  

    A novel technique to extend the phasing range of the vector sum phase shifter by exploiting its second order response is proposed and implemented. A continuously variable phase shift is demonstrated between 8 and 16 GHz with phasing range exceeding 450° measured at 16 GHz. Good agreement between the predictions and measurements has been obtained. View full abstract»

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  • Continuous phase shift of sinusoidal signals using injection locked oscillators

    Publication Year: 2005 , Page(s): 312 - 314
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB) |  | HTML iconHTML  

    This work presents an alternative to generate continuous phase shift of sinusoidal signals based on the use of super harmonic injection locked oscillators (ILO). The proposed circuit is a second harmonic ILO with varactor diodes as tuning elements. In the locking state, by changing the varactor bias, a phase shift instead of a frequency shift is observed at the oscillator output. By combining two of these circuits, relative phases up to ±90° could be achieved. Two prototypes of the circuit have been implemented and tested, a hybrid version working in the range of 200-300 MHz and a multichip module (MCM) version covering the 900-1000 MHz band. View full abstract»

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  • A wideband low noise amplifiers design incorporating the CMRC circuitry

    Publication Year: 2005 , Page(s): 315 - 317
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB) |  | HTML iconHTML  

    An impedance bandwidth enhancement technique for tuning a low noise amplifier (LNA) is presented. With the use of the compact microstrip resonant cell (CMRC) at the emitter pins of a bipolar junction transistor (BJT), the impedance bandwidth achieved is about 95%, for a simple single stage amplifier design. The LNA attains a gain of about 15 dB; also a low noise figure of 1.16 dB at 2.1GHz and an average noise figure of about 1.5 dB across the operation bands have been achieved. View full abstract»

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  • K-band 3-D MMIC low noise amplifier and mixer using TFMS lines with ground slit

    Publication Year: 2005 , Page(s): 318 - 320
    Cited by:  Papers (3)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (256 KB) |  | HTML iconHTML  

    Three-dimensional (3-D) microwave monolithic integrated circuit (MMIC) technology, that incorporates slits in the ground metal, was applied to K-band low noise amplifier (LNA) and I/Q mixer to provide a low cost solution for various K-band receivers such as for P-to-P radio, WLAN, and UWB sensors. The LNA incorporates a quasicoplanar stub in the input-matching network, improving the noise figure by 1 dB. This low-noise amplifier (LNA) exhibits a noise figure of 2.5 dB with an associated gain of 16 dB and an area of 0.75×0.65 mm2. The I/Q resistive mixer incorporates a broadside 3-dB coupler with a 22-μm-wide slit in the ground metal beneath the coupled thin-film micro-strip (TFMS) lines (patent pending). The insertion loss of the 3 dB coupler is 0.75 dB. The I/Q mixer exhibits a conversion loss of less than 14 dB at 0.1-2.0GHz IF frequencies for 2-dBm local input power. These LNA and mixer potentially make it easier to integrate receiver functions in a die. View full abstract»

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  • A CMOS RF front-end for a multistandard WLAN receiver

    Publication Year: 2005 , Page(s): 321 - 323
    Cited by:  Papers (23)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (273 KB) |  | HTML iconHTML  

    This letter describes the design and performance of a dual band tri-mode receiver front-end compliant with the IEEE 802.11a, b, and g standards. The receiver front-end was built in a 0.18-μm CMOS process and achieves a noise figure of 4.7 dB/5.1 dB for the 2.4-GHz/5-GHz bands, respectively. The receiver front-end provides a dual gain mode of 5 dB/30 dB with an IIP3 of -1dBm for the low gain mode. The front-end draws 25 mA/27 mA from a 1.8-V supply for the 2.4-GHz/5-GHz bands, respectively. View full abstract»

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  • Analytical approach to evaluate thermal reduction effects of peripheral structures on microwave power GaAs device chips

    Publication Year: 2005 , Page(s): 324 - 326
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (176 KB) |  | HTML iconHTML  

    Thermal analysis of microwave power GaAs device chips has been presented that features analytical simplicity yet gives quantitative evaluation of thermal reduction effects of two kinds of chip peripheral structures, via-holes and bumps. To calculate Tmax (maximum temperature) and Rth (thermal resistance), the Laplace equation has been solved for a basic chip model under boundary conditions appropriate to peripheral structures. The chip model consisted of three layers features having heat sources at interface of layer 2 and 3. An approximate method for the analysis of field effect transistor (FET) unit with bumps has been newly proposed. A good agreement has been found between the calculated and measured Rth and its reduction effect, verifying the usefulness of the present analysis in the thermal design of device chips. View full abstract»

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  • A 5-GHz low phase noise differential colpitts CMOS VCO

    Publication Year: 2005 , Page(s): 327 - 329
    Cited by:  Papers (47)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (431 KB) |  | HTML iconHTML  

    A low noise 5-GHz differential Colpitts CMOS voltage-controlled oscillator (VCO) is proposed in this letter. The Colpitts VCO core adopts only PMOS in a 0.18-μm CMOS technology to achieve a better phase noise performance since PMOS has lower 1/f noise than NMOS. The VCO operates from 4.61 to 5 GHz with 8.3% tuning range. The measured phase noise at 1-MHz offset is -120.42 dBc/Hz at 5 GHz and -120.99 dBc/Hz at 4.61 GHz. The power consumption of the VCO core is only 3 mW. To the authors' knowledge, this differential Colpitts CMOS VCO achieves the best figure of merit (FOM) of 189.6 dB at 5-GHz band. View full abstract»

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  • A microwave frequency divider using an inverter ring and transmission gates

    Publication Year: 2005 , Page(s): 330 - 332
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (463 KB) |  | HTML iconHTML  

    A divide-by-four frequency divider is presented that uses a CMOS inverter ring interspersed with transmission gates. The presence of the transmission gates prevents the inverter ring from oscillating. The signal to be divided is applied to the control voltage to the transmission gates. The integrated circuit operates at an input frequency of 2.2 GHz and yields an output signal at 0.55 GHz. The power dissipation is 14.4 mW. The IC was fabricated using 0.18 μm CMOS technology. View full abstract»

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  • A highly-integrated Doherty amplifier for CDMA handset applications using an active phase splitter

    Publication Year: 2005 , Page(s): 333 - 335
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (280 KB) |  | HTML iconHTML  

    A highly-integrated "extended" Doherty-type amplifier has been developed for code-division multiple access (CDMA) applications. In order to overcome the size limit of the Doherty amplifiers for reduced form-factor applications such as handsets, bulky input quadrature coupler and output λ/4-line transformers have been replaced with an active phase splitter and lumped-element networks, respectively. The active phase splitter provides inherent gain and isolation. All the components except for the output circuits have been integrated on a single chip with a size of 1.1 mm×1.4 mm. The measured data of the proposed Doherty amplifier showed better than -45 dBc adjacent channel power ratio (ACPR) over the entire power range, and 16% and 38% efficiencies at 16 and 28 dBm, respectively. The average current consumption calculated using urban compact disk game (CDG) usage profile was reduced from 76 mA (conventional class-AB amplifier) to 31 mA using our approach. This concept can be applied to a variety of wireless TX applications requiring small form factors and enhanced efficiencies. View full abstract»

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  • 5-GHz CMOS LC VCOs with wide tuning ranges

    Publication Year: 2005 , Page(s): 336 - 338
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (459 KB) |  | HTML iconHTML  

    A 4.8-GHz LC voltage-controlled oscillator (VCO) optimized for maximum tuning range was designed and fabricated using 0.25-μm 1P5M CMOS process. The optimized design used an inverse proportionality between the two parasitic capacitances of the inductor and the MOS transistors for minimizing the parasitic capacitance at the oscillation node. The fabricated LC VCO has a wide tuning range of 20.3% from 4.32 GHz to 5.3 GHz with a power dissipation of 7.3 mW. This tuning range performance is comparable to, or better than, those of the reported CMOS LC VCOs in 5-GHz band. The measured phase noise is -82 dBc/Hz and -114.6 dBc/Hz at 100 KHz and 1-MHz offset, respectively. View full abstract»

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  • A 60-GHz multilayer parasitic microstrip array antenna on LTCC substrate for system-on-package

    Publication Year: 2005 , Page(s): 339 - 341
    Cited by:  Papers (29)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (224 KB) |  | HTML iconHTML  

    This letter describes a compact and high-gain multilayer parasitic microstrip array antenna (MPMAA). The design and performance of the proposed array antenna are presented. The antenna employs three layers with a 2×2 parasitic array on each layer. The developed prototype MPMAA employs a multilayer low-temperature co-fired ceramic (LTCC) substrate that is well suited to the assembly of MMIC chips. The fabricated MPMAA achieves a 7.17 dBi absolute gain at 60 GHz including the loss derived from the feeding parts and RF probe to measure its antenna performance. The spacing of the top layer of the parasitic array constructed by 2×2 elements has a free-space wavelength of 0.36 and the chip size is 10 mm2. The fabricated MPMAA achieves both compact and high directional gain and satisfies the requirements for a millimeter-wave system-on-package (SOP). View full abstract»

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  • Millimeter-wave twin tapered-slot antenna

    Publication Year: 2005 , Page(s): 342 - 344
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (264 KB) |  | HTML iconHTML  

    A millimeter-wave twin tapered-slot antenna on standard substrate is presented. The twin antenna is constructed by single tapered slot antennas (TSA), printed on opposite sides of a low dielectric constant (εr=2.2) substrate. The structure is fed by a rectangular waveguide followed by a broadband finline-to-slotline power splitter. The radiation pattern of the single TSAs is improved by corrugating the taper contour by a series of short-circuited stubs. With this method, antennas three times thicker compared with conventional TSA designs can be realized with an almost unchanged performance. Experimental radiation patterns of a 65-GHz twin TSA in comparison to both simulation results and corresponding single TSA measurements are presented. A measured twin antenna gain of 17.5 dB indicates efficient radiation. View full abstract»

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  • Radiation from a ferrite-filled rectangular waveguide with multiple slits

    Publication Year: 2005 , Page(s): 345 - 347
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB) |  | HTML iconHTML  

    Radiation from a ferrite-filled waveguide with multiple thick slits is investigated. The Fourier transform and mode matching are utilized to obtain a rigorous solution. The effect of the ferrite linewidth is included to account for the magnetic loss of ferrite. The maximum beam steering ratio 4.33°/100 oe is achieved with the magnetic bias field ranging from 1000 to 1400 oe. The ferrite-filled rectangular waveguide with nine slits is fabricated and its radiation patterns are measured at X-band. Our computational results agree with measurement data. View full abstract»

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  • Dielectric slab Rotman lens

    Publication Year: 2005 , Page(s): 348 - 350
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (352 KB) |  | HTML iconHTML  

    A new form of a Rotman lens has been proposed for applications above 10 GHz, such as a collision avoidance radar. The proposed lens can be described as a dielectric slab fed by slot lines. The new form is expected to show lower loss and lower mutual coupling than the conventional Rotman lenses at higher frequency than 10 GHz. The prototype was implemented with nine beam ports and nine array ports. The measurements show that the mutual coupling can be lowered at higher frequency, and that the efficiency of the dielectric slab lens of about 30% can be obtained. We conclude that the dielectric lens is comparable to the conducting plate lens even though a spillover loss is presumed at frequency of the implementation. View full abstract»

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  • Partial H-plane filters with partially inserted H-plane metal vane

    Publication Year: 2005 , Page(s): 351 - 353
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB) |  | HTML iconHTML  

    A partial H-plane filter, which can be compared with a conventional E-plane filter, is proposed as a new type of compact direct-coupled resonator filter. The partial H-plane filter has the same frequency response as that of the E-plane filter while its cross section is one quarter. Measured results are in good agreement with computed results. View full abstract»

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  • A high-Q quasi-planar filtering solution for 60-GHz applications

    Publication Year: 2005 , Page(s): 354 - 356
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (442 KB) |  | HTML iconHTML  

    A low insertion loss 2.2% bandwidth two-pole cavity filter was fabricated at 60 GHz by bonding metallized lids on each side of a 250-μm silicon substrate. The lids are made by dry etching of a 500-μm silicon substrate. The same process is used to etch via holes on the intermediate substrate. The position of these via holes fixes the external coupling and the coupling between the resonators. The measured unloaded quality factor is lied on the height of the cavity (1.05 mm) and is around 1100. View full abstract»

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  • An interdigital bandpass filter embedded in LTCC for 5-GHz wireless LAN applications

    Publication Year: 2005 , Page(s): 357 - 359
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB)  

    This letter presents a compact interdigital stripline bandpass filter embedded in low temperature cofired ceramic for 5-GHz wireless LAN applications, including design, simulation, fabrication, and measurements. The filter measures 8 mm×7 mm×1.1 mm and exhibits an insertion loss of 3.6 dB, a return loss of 20 dB, and a 212-MHz passband with the midband frequency at 5.28 GHz. The filter is highly reproducible with good tolerance. A low noise amplifier (LNA) built on the top of the LTCC substrate with an embedded filter has the same bandwidth and midband frequency as those of the filter. Using this filter and an integrated chip, a small RF front-end receiver has been achieved. View full abstract»

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  • Filtering functions with reduced fabrication sensitivity

    Publication Year: 2005 , Page(s): 360 - 362
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (144 KB) |  | HTML iconHTML  

    A new category of filtering functions is proposed. Reflection zeros are redistributed to provide higher attenuation lobes near the band edge compared to the lobes near the center frequency. The ripple in the passband is smallest near the band edges mitigating the sensitivity of return and insertion loss within the passband while providing better selectivity compared to chained function filters. View full abstract»

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  • Tunable notch filter of ferrite-filled grooves in parallel plates

    Publication Year: 2005 , Page(s): 363 - 365
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (408 KB) |  | HTML iconHTML  

    The characteristics of tunable notch filter of ferrite-filled grooves in parallel plates are investigated. The Fourier transform and mode matching is used to obtain a simple, rigorous solution. The 8.6 to 11.3 GHz tuning has been achieved with the dc magnetic field varying from 0 to 5830oe. The comparison between our theory and measurement data using a rectangular waveguide shows a good agreement. 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.

Full Aims & Scope