By Topic

Microwave and Wireless Components Letters, IEEE

Issue 1 • Date Jan. 2002

Filter Results

Displaying Results 1 - 11 of 11
  • Determination of receiver selectivity and transmit frequency using a common resonator

    Page(s): 1 - 2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (39 KB) |  | HTML iconHTML  

    In this work, the determination of receiver selectivity and transmit frequency using a common resonator is presented for a 5.3 GHz transceiver employing a time division duplex, on-off keyed modulation format. The microstrip circuit is fabricated on Rogers RO4003/sup (R)/, a high frequency laminate. In receive mode, a 3 dB passband of 35 MHz and a small-signal gain of 26 dB has been achieved. In transmit mode, an output power of +7 dBm for the fundamental, -15.0 dBm for the second harmonic, -18.0 dBm for the third harmonic, and -35.0 dBm for the fourth harmonic has been achieved. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Tunable barium strontium titanate thin film capacitors for RF and microwave applications

    Page(s): 3 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (66 KB) |  | HTML iconHTML  

    The measurement results for thin film barium strontium titanate (BST) based voltage tunable capacitors intended for RF applications are reported. At 9 V DC, BST capacitors fabricated using MOCVD (metalorganic chemical vapor deposition) method achieved 71% (3.4:1) tunability. The measured device quality factor (Q) for BST varactors is comparable with the device Q for commercially available varactor diodes of similar capacitance. The typical dielectric loss tangent was in the range 0.003-0.009 at VHF. Large signal measurement and modeling results for BST thin film capacitors are also presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Miniaturized Wilkinson power dividers utilizing capacitive loading

    Page(s): 6 - 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (60 KB) |  | HTML iconHTML  

    The authors report the miniaturization of a planar Wilkinson power divider by capacitive loading of the quarter wave transmission lines employed in conventional Wilkinson power dividers. Reduction of the transmission line segments from /spl lambda//4 to between /spl lambda//5 and /spl lambda//12 are reported here. The input and output lines at the three ports and the lines comprising the divider itself are coplanar waveguide (CPW) and asymmetric coplanar stripline (ACPS), respectively. The 10 GHz power dividers are fabricated on high resistivity silicon (HRS) and alumina wafers. These miniaturized dividers are 74% smaller than conventional Wilkinson power dividers, and have a return loss better than +30 dB and an insertion loss less than 0.55 dB. Design equations and a discussion about the effect of parasitic reactance on the isolation are presented for the first time. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Spatial power splitting and combining based on the Talbot effect

    Page(s): 9 - 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (64 KB) |  | HTML iconHTML  

    The Talbot effect, a multimode interference phenomenon, is investigated as a technique for combining power from solid-state devices in order to generate higher levels of microwave and millimeter-wave power in a process referred to as quasioptical or spatial power combining. We explore the feasibility of using the Talbot effect to implement a 1 /spl times/ 8 power splitter and an 8 /spl times/ 1 power combiner at 94 GHz. We report the first demonstration of the multimode interface phenomenon in a planar waveguide at 8 GHz. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Quasi-static finite-element analysis of a skewed microstrip crossover

    Page(s): 12 - 14
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (68 KB) |  | HTML iconHTML  

    In this work, we present a quasistatic analysis of a microstrip crossover on a dielectric substrate. The microstrips are located at different planes and may cross at an arbitrary angle. Capacitances and inductances are calculated from scalar potentials. For magnetostatic formulation, the boundary conditions for scalar potential are introduced by means of partitioning surfaces. The use of the adaptive finite element method provides the required flexibility with respect to the analyzed geometry, optimal discretization and good efficiency. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A compact single layer injection-locked linear scanning array

    Page(s): 15 - 17
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (89 KB) |  | HTML iconHTML  

    A compact, single layer, CPW-fed, patch scanning array architecture using injection locking at 9.83 GHz is presented. The patch antennas are printed on the front side of the substrate while the electronics are situated at the back side leading to a simple and compact design. The unit element for the array is a self oscillating active patch antenna with a GaAs FET centered behind the patch for tight packing. The feedback for the oscillator is provided through electromagnetic coupling using a twin-slot arrangement behind the patch. A low power control signal is injected through parasitic coupling at the CPW side of the circuit. Phase shifting of the elements is achieved by electronically adjusting the gate voltage of the GaAs FETs. A scan range of -12/spl deg/- +9.5/spl deg/ is obtained for a four element prototype array. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A compact circularly polarized subdivided microstrip patch antenna

    Page(s): 18 - 19
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (68 KB) |  | HTML iconHTML  

    A compact circularly polarized subdivided microstrip patch antenna is proposed. The antenna is composed of the interconnection of four corner patches alternating with four strips and a fifth central patch. It presents the very small size of 0.28/spl lambda//sub g/ by 0.28/spl lambda//sub g/ at resonance (5.85 GHz), which represents a surface reduction of 60% compared with a conventional microstrip square patch antenna. The proposed antenna exhibits a gain of 4.3 dBi to 5 dBi and an axial ratio lower than 1.8 dB in the range of its bandwidth, which is of 30 MHz. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Ultra-wide band corrugated gaussian profiled horn antenna design

    Page(s): 20 - 21
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (65 KB) |  | HTML iconHTML  

    Nowadays, an increasing number of applications need stable radiation patterns with low sidelobes and low crosspolar levels in a very wide bandwidth. Gaussian profiled horn antennas (GPRAs) have demonstrated their feasibility as one of the best solutions. A corrugated Gaussian horn antenna design with more than 40% bandwidth is proposed. The measured radiated far field patterns are in good agreement with the simulated ones. The measured results show a Gaussian antenna with extremely wide bandwidth, low sidelobes, and low crosspolar levels. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A transformer of one-third wavelength in two sections - for a frequency and its first harmonic

    Page(s): 22 - 23
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (61 KB) |  | HTML iconHTML  

    The quarter-wave transformer transforms in one frequency f/sub 0/, but not its first harmonic 2f/sub 0/. The transform in 2f/sub 0/ is needed in a dual-band operation of GSM and PCS. This requirement can be fulfilled in a two line-sections of 1/6 wavelengths each, adding to 1/3 wavelengths for the total transformer length in the lower band centering at f/sub 0/ (fundamental), or 2/3 wavelengths in the upper band centering at 2f/sub 0/ (1st harmonic). The 1/3-wave transformer is analytically inexact but effectively exact for engineering applications. For example, for impedance transforms of K = 4, the inexactness gives a reflection of |/spl Gamma/| = 0.013. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Parallel implementation of the steepest descent fast multipole method (SDFMM) on a Beowulf cluster for subsurface sensing applications

    Page(s): 24 - 26
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (43 KB)  

    We present the parallel, MPI-based implementation of the SDFMM computer code using a thirty-two node Intel Pentium-based Beowulf cluster. The SDFMM is a fast algorithm that is a hybridization of the method of moments (MoMs), the fast multipole method (FMM), and the steepest descent integration path (SDP), which is used to solve large-scale linear systems of equations produced in electromagnetic scattering problems. An overall speedup of 7.2 has been achieved on the 32-processor Beowulf cluster and a significant reduced runtime is achieved on the 4-processor 667 MHz Alpha workstation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Patent abstracts

    Page(s): 27 - 33
    Save to Project icon | Request Permissions | PDF file iconPDF (181 KB)  
    Freely Available from IEEE

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