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Microwave Theory and Techniques, IEEE Transactions on

Issue 7 • Date July 2007

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  • Table of contents

    Publication Year: 2007 , Page(s): C1 - C4
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  • IEEE Transactions on Microwave Theory and Techniques publication information

    Publication Year: 2007 , Page(s): C2
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  • SiGe HBT's Small-Signal Pi Modeling

    Publication Year: 2007 , Page(s): 1417 - 1424
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (766 KB) |  | HTML iconHTML  

    This paper presents the derivation procedure used in determining the parameters in SiGe HBT's small-signal model where the Pi circuit configuration is employed. For both the transistor's external base-collector capacitor and its base spreading resistor, new close-form expressions have been derived. Comparisons with existing approaches vindicate the feasibility and effectiveness of our formulations. With the impact of the lossy substrate effectively modeled and the frequency dependency of the transconductance properly addressed, this proposed extraction approach demonstrates accurate results up to 30 GHz with different bias conditions. View full abstract»

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  • Wideband Nonlinear Response of High-Temperature Superconducting Thin Films From Transmission-Line Measurements

    Publication Year: 2007 , Page(s): 1425 - 1430
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (543 KB) |  | HTML iconHTML  

    We report on a technique for extracting an accurate value of the nonlinear inductance in superconducting transmission lines. This novel technique assesses the frequency dependence of the transmission line's nonlinear response. A wideband nonlinear measurement system was used to simultaneously measure the third-order spurious signals at 2f1 - f2, 2f2 - f1 + f2, 2f2 + f1, 3f1, and 3f2 frequencies. Measurements for different values of the fundamental frequencies f1 and f2 allow us to study the spurious signal generation from 1 to 21 GHz. We demonstrate this technique by measuring several superconducting YBa2Cu3O7-x coplanar waveguide transmission line geometries patterned in a single chip at 80 K. The results show a linear frequency dependence of the nonlinear response, indicating a dominant contribution of the nonlinear inductance over the nonlinear resistance omegaDeltaL(i) Gt DeltaR(i). The experimentally obtained nonlinear inductances are then used to determine device-independent measures of the linearity of the thin-film material in order to provide the foundation for modeling the nonlinear response of specific devices. View full abstract»

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  • Ultra-Wideband Multifunctional Communications/Radar System

    Publication Year: 2007 , Page(s): 1431 - 1437
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (501 KB) |  | HTML iconHTML  

    We have designed, simulated, fabricated, and tested an ultra-wideband (UWB) multifunctional communication and radar system utilizing a single shared transmitting antenna aperture. Two surface acoustic wave bandpass chirp filters were used to modulate the radar and communications pulses, generating linear frequency modulation waveforms with opposite slope factors. The system operates at a center frequency of 750 MHz with 500 MHz of instantaneous bandwidth. The measured range resolution is 63 cm (25 in) using targets with a radar cross section of 2.7 m2. The probability of detection was measured to be 99%, and the probability of false alarm was 7% with the communication and radar systems operating simultaneously. The bit error rate for simultaneous communication at 1 Mb/s, and radar at 150 kHz pulse repetition frequency and 1.5-ns pulsewidth is 2e - 3. Our UWB multifunctional system demonstrates the ability to simultaneously interrogate the environment and communicate through a shared transmitting antenna aperture, while realizing a simple system architecture with low output power and not employing time-division multiplexing. View full abstract»

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  • A Quadrature Radar Topology With Tx Leakage Canceller for 24-GHz Radar Applications

    Publication Year: 2007 , Page(s): 1438 - 1444
    Cited by:  Papers (8)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1618 KB) |  | HTML iconHTML  

    A quadrature radar topology with a Tx leakage canceller is presented. The canceller is composed of four branch-line hybrid couplers, a 90deg delay line, and a Wilkinson combiner. It has high Tx-to-Rx isolation and wide bandwidth characteristics. The isolation is 35.27 dB at 24 GHz and does not drop below 30 dB over a 2-GHz bandwidth. Given that the isolation of the branch-line hybrid coupler is 21.5 dB, the enhancement of the isolation is expected to be 13.77 dB. A quadrature Doppler radar front-end with the canceller was implemented. The noise level in the mixer output is lower by 9 dB compared with that of a conventional quadrature radar. This radar can measure speed as low as 0.76 mm/s, which correspond to a 0.12-Hz Doppler shift. It is also able to detect signs of the Doppler shift from a moving target due to its quadrature topology. View full abstract»

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  • Design of Ultra-Low-Voltage RF Frontends With Complementary Current-Reused Architectures

    Publication Year: 2007 , Page(s): 1445 - 1458
    Cited by:  Papers (43)  |  Patents (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1681 KB) |  | HTML iconHTML  

    In this paper, ultra-low-voltage circuit techniques are presented for CMOS RF frontends. By employing a complementary current-reused architecture, the RF building blocks including a low-noise amplifier (LNA) and a single-balanced down-conversion mixer can operate at a reduced supply voltage with microwatt power consumption while maintaining reasonable circuit performance at multigigahertz frequencies. Based on the MOSFET model in moderate and weak inversion, theoretical analysis and design considerations of the proposed circuit techniques are described in detail. Using a standard 0.18-mum CMOS process, prototype frontend circuits are implemented at the 5-GHz frequency band for demonstration. From the measurement results, the fully integrated LNA exhibits a gain of 9.2 dB and a noise figure of 4.5 dB at 5 GHz, while the mixer has a conversion gain of 3.2 dB and an IIP3 of -8 dBm. Operated at a supply voltage of 0.6 V, the power consumptions of the LNA and the mixer are 900 and 792 muW, respectively. View full abstract»

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  • Electrical Backplane Equalization Using Programmable Analog Zeros and Folded Active Inductors

    Publication Year: 2007 , Page(s): 1459 - 1466
    Cited by:  Papers (3)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (663 KB) |  | HTML iconHTML  

    In this paper, we present a low-power small-area electrical backplane equalizer using programmable analog zeros and folded active inductors. We also present a dc-offset cancellation circuit, which occupies less chip area than the traditional offset cancellation schemes. The equalizer circuit was fabricated in a 1.0-V 90-nm CMOS process. With one zero stage, the equalizer occupies 0.015-mm2 chip area and dissipates 12 mW of power. At 4.25-Gb/s data rate, the equalizer provides 7.8-dB gain boost at the Nyquist frequency. Without the use of any transmitter equalization, the analog zero equalizer demonstrated error-free transmission for pseudorandom-bit-sequence-31 data patterns over 34-in lossy FR4 backplanes. View full abstract»

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  • Monolithic Integration of a Folded Dipole Antenna With a 24-GHz Receiver in SiGe HBT Technology

    Publication Year: 2007 , Page(s): 1467 - 1475
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1002 KB) |  | HTML iconHTML  

    The integration of an on-chip folded dipole antenna with a monolithic 24-GHz receiver manufactured in a 0.8-mum SiGe HBT process is presented. A high-resistivity silicon substrate (1000 Omega ldr cm) is used for the implemented circuit to improve the efficiency of the integrated antenna. Crosstalk between the antenna and spiral inductors is analyzed and isolation techniques are described. The receiver, including the receive and an optional transmit antenna, requires a chip area of 4.5 mm2 and provides 30-dB conversion gain at 24 GHz with a power consumption of 960 mW. View full abstract»

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  • A 4-bit CMOS Phase Shifter Using Distributed Active Switches

    Publication Year: 2007 , Page(s): 1476 - 1483
    Cited by:  Papers (20)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1849 KB) |  | HTML iconHTML  

    This paper presents a novel 4-bit phase shifter using distributed active switches in 0.18-mum RF CMOS technology. The relative phase shift, which varies from 0deg to 360deg in steps of 22.5deg, is achieved with a 3-bit distributed phase shifter and a 180deg high-pass/low-pass phase shifter. The distributed phase shifter is implemented using distributed active switches that consist of a periodic placement of series inductors and cascode transistors, thereby obtaining linear phase shift versus frequency with a digital control. The design guideline of the distributed phase shifter is presented. The 4-bit phase shifter achieves 3.5 plusmn 0.5 dB of gain, with an rms phase error of 2.6deg at a center frequency of 12.1 GHz. The input and output return losses are less than -15 dB at all conditions. The chip size is 1880 mum times 915 mum including the probing pads. View full abstract»

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  • A New Brillouin Dispersion Diagram for 1-D Periodic Printed Structures

    Publication Year: 2007 , Page(s): 1484 - 1495
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1354 KB) |  | HTML iconHTML  

    Dispersion and radiation properties for bound and leaky modes supported by 1-D printed periodic structures are investigated. A new type of Brillouin diagram is presented that accounts for different types of physical leakage, namely, leakage into one or more surface waves or also simultaneously into space. This new Brillouin diagram not only provides a physical insight into the dispersive behavior of such periodic structures, but it also provides a simple and convenient way to correctly choose the integration paths that arise from a spectral-domain moment-method analysis. Numerical results illustrate the usefulness of this new Brillouin diagram in explaining the leakage and stopband behavior for these types of periodic structures. View full abstract»

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  • A Nonlinear Finite-Element Leaky-Waveguide Solver

    Publication Year: 2007 , Page(s): 1496 - 1510
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1073 KB) |  | HTML iconHTML  

    A novel hybrid finite-element method for the analysis of leaky-waveguide structures is presented. The possibly radiating structure is enclosed within a fictitious circular contour-C in order to truncate the infinite solution domain. The field in the unbounded domain, outside contour-C, is expressed as a superposition of transverse electric and magnetic modes. Their radial dependence is expressed in terms of Hankel functions, which satisfy the radiation condition at infinity. The bounded area is discretized using hybrid node/edge elements for an accurate and efficient handling of the electric field vector wave equation. The transparency of the fictitious contour is ensured by enforcing the field continuity conditions according to the principles of a vector Dirichlet-to-Neumann mapping. The whole procedure yields a nonlinear eigenvalue problem for the complex axial propagation constant (beta). The nonlinearity is due to the appearance of beta within the argument of the Hankel functions. The final nonlinear problem is solved by employing a matrix Regula-Falsi algorithm. Initial guesses for the Regula-Falsi algorithm and a fast estimation of the eigenvalues spectrum are provided by a linear formulation based on a second-order approximation (beta/ko)2 Lt 1. The proposed method is validated against published numerical and experimental results for both leaky and surface wave modes. View full abstract»

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  • Effects of Losses on the Current Spectrum of a Printed-Circuit Line

    Publication Year: 2007 , Page(s): 1511 - 1519
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1309 KB) |  | HTML iconHTML  

    This paper studies the effects of practical conductor and dielectric losses on the high-frequency current excited on a microstrip line by a gap voltage source. The analysis shows that whereas losses cause an exponential decay in the propagating bound mode (as expected), the continuous-spectrum current is much less influenced by the presence of material losses. As a consequence, the nature of the strip current far away from the source is dramatically affected by the presence of losses, and will be dominated by the continuous spectrum. This results in unusual behavior that is observed for the strip current far away from the source. View full abstract»

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  • Microwave Circuit Design by Means of Direct Decomposition in the Finite-Element Method

    Publication Year: 2007 , Page(s): 1520 - 1530
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1176 KB) |  | HTML iconHTML  

    In this paper, a domain decomposition approach for design purposes is proposed. The analysis domain is divided into subdomains according to the arbitrarily shaped parts that should be modified in the synthesis process. A full-wave matrix-valued transfer function describes each decomposition subdomain, namely, an admittance-type matrix. Field continuity between subdomains is directly enforced by an admittance matrix connection. This methodology makes it possible to analyze only those parts of the analysis domain that are supposed to evolve in order to satisfy the design specifications. Furthermore, several modifications in the shape of the components are allowed as a consequence of the easy matrix connection process, where the consideration of different admittance-type matrices or absence of them gives rise to distinct geometric structures. A model order reduction technique is also considered for fast frequency sweeping. Finally, several numerical examples illustrate the capabilities of the proposed procedure, as well as its accuracy. View full abstract»

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  • Bandwidth-Compensation Method for Miniaturized Parallel Coupled-Line Filters

    Publication Year: 2007 , Page(s): 1531 - 1538
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (596 KB) |  | HTML iconHTML  

    This paper proposes a bandwidth-compensation method for miniaturized filters based on short-ended parallel coupled lines. Capacitive loading of such coupled lines is a relatively simple means of reducing the line lengths. In this study, a method is developed that predicts exactly the degree of reduction in the fractional bandwidth due to miniaturization. Using this method, the fractional bandwidth of the prototype coupled line filter can be adjusted, enabling miniaturized filters to maintain the targeted fractional bandwidth. The proposed bandwidth-compensation method applies for any type of filters with coupled lines realized with various transmission lines, with uniform or nonuniform line lengths. Experimental results are also presented that verify the validity of the method. View full abstract»

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  • Miniaturized Dual-Mode Ring Bandpass Filters With Patterned Ground Plane

    Publication Year: 2007 , Page(s): 1539 - 1547
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1111 KB) |  | HTML iconHTML  

    Miniaturized dual-mode ring bandpass filters with a patterned ground plane are proposed. By loading the resonator periodically with the butterfly radial slot cells on the ground plane, the size of a ring filter is reduced along with an extended upper stopband. Based on the equivalent circuits, the mode-splitting characteristics and impact of the patterned ground plane on the electrical performances of the filter are investigated. A slotline ring filter with a patterned ground plane is also proposed. The miniaturization is achieved by loading the periphery of the slotline ring with the butterfly radial stubs at the backside. The filter has a higher first spurious response and deeper stopband rejection than a conventional microstrip ring filter. Measured results validate the analysis and theoretical prediction with good agreement. View full abstract»

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  • Design and High Performance of a Micromachined K -Band Rectangular Coaxial Cable

    Publication Year: 2007 , Page(s): 1548 - 1553
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (675 KB) |  | HTML iconHTML  

    This paper presents the design and performance of a low-loss rectangular air-filled coaxial cable. A high-precision micromachining technique is used to fabricate the cable. It is assembled by bonding together five layers of gold-coated SU-8 photoresist fabricated using the ultraviolet photolithographic technique. As the cable is air filled, both the dielectric and radiation losses are negligible. The cross coupling is also very weak between the cable and other parts of the circuit in a system. These advantages make the proposed cable a very good candidate for low-cost high-performance miniaturized transmission lines. The cable is designed to work in the frequency range of 14-36 GHz, which covers the whole JC-band. The size of the cable is only 8.9 mm times 8.6 mm times 1.5 mm and the measured minimum insertion loss of the as-made cable is approximately 0.6 dB. The return loss is better than 15 dB in the passband. View full abstract»

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  • A Swept-Frequency Measurement of Complex Permittivity and Complex Permeability of a Columnar Specimen Inserted in a Rectangular Waveguide

    Publication Year: 2007 , Page(s): 1554 - 1567
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1526 KB) |  | HTML iconHTML  

    This paper proposes a new method for the swept-frequency measurement of a solid material's complex permittivity and complex permeability. The proposed method utilizes a columnar specimen inserted in a rectangular waveguide, and the two-port S-parameters of the specimen are measured. In the analysis, the S-parameters are rigorously formulated in which the waveguide's fundamental mode, as well as the higher order modes are taken into account. Measurement was performed by using a standard waveguide and three types of materials as specimens. Results were compared with the conventional transmission-line method using the same rectangular waveguide. It is confirmed that the complex permittivity and complex permeability measured by the proposed method agrees very well with those measured by the conventional transmission-line method. View full abstract»

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  • Phase and Amplitude Noise Analysis in Microwave Oscillators Using Nodal Harmonic Balance

    Publication Year: 2007 , Page(s): 1568 - 1583
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1065 KB) |  | HTML iconHTML  

    In this paper, a nodal harmonic balance (HB) formulation is presented for the phase and amplitude noise analysis of free-running oscillators. The implications of using different constraints in the resolution of the perturbed-oscillator equations are studied. The obtained formulation allows the prediction of the possible spectrum resonances without ill conditioning at low frequency offset from the carrier. The noise spectrum is meaningfully expressed in terms of the eigenvalues of a newly defined matrix, obtained from the linearization of the nodal HB system about the steady-state solution. The cases of real or complex-conjugate dominant eigenvalues are distinguished. The developed phase-noise formulation is extended to a system of two coupled oscillators. The phase and amplitude noise analyses have been applied to a push-push oscillator at 18 GHz, a bipolar oscillator at 1 GHz, and a coupled system of two field-effect transistor oscillators at 6 GHz. View full abstract»

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  • IEEE Transactions on Microwave Theory and Techniques information for authors

    Publication Year: 2007 , Page(s): 1584
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    Freely Available from IEEE
  • IEEE Microwave Theory and Techniques Society Information

    Publication Year: 2007 , Page(s): C3
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The IEEE Transactions on Microwave Theory and Techniques focuses on that part of engineering and theory associated with microwave/millimeter-wave components, devices, circuits, and systems involving the generation, modulation, demodulation, control, transmission, and detection of microwave signals. This includes scientific, technical, and industrial, activities. Microwave theory and techniques relates to electromagnetic waves usually in the frequency region between a few MHz and a THz; other spectral regions and wave types are included within the scope of the Society whenever basic microwave theory and techniques can yield useful results. Generally, this occurs in the theory of wave propagation in structures with dimensions comparable to a wavelength, and in the related techniques for analysis and design..

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