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Microwave and Guided Wave Letters, IEEE

Issue 5 • Date May 1992

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Displaying Results 1 - 15 of 15
  • Full-wave analysis of guided wave structures using a novel 2-D FDTD

    Publication Year: 1992 , Page(s): 165 - 167
    Cited by:  Papers (58)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (208 KB)  

    A two-dimensional Yee's mesh with reduced grid size is proposed for the full-wave analysis of arbitrarily shaped guided wave structures. By introducing a phase shift beta Delta h along the z-direction (propagation direction), it is possible to calculate the propagation constant, of hybrid modes by using only a two-dimensional mesh. This step not only allows the frequency selective application of the finite-difference time-domain (FDTD) method, as desired in many design problems, but it also reduces the memory space and CPU time of the full-wave FDTD significantly. Furthermore, by introducing a phase shift, the space grid in the propagation direction is reduced to half its normal size.<> View full abstract»

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  • Inset dielectric guide mounting of a detector diode

    Publication Year: 1992 , Page(s): 168 - 170
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (202 KB)  

    Inset dielectric guide (IDG) is an alternative to dielectric guides such as image or insular guides for millimeter-wave and antenna applications. A simple detector diode mount is examined, and its performance in IDG is compared to that achieved when the same diode is mounted in a rectangular metal waveguide. The performance in IDG is good, although it is a little worse than in the waveguide due to some radiation from the diode mount.<> View full abstract»

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  • Measurement of a 24-GHz broad-band multilayer ceramic feedthru for microwave packaging

    Publication Year: 1992 , Page(s): 171 - 173
    Cited by:  Patents (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (261 KB)  

    A feedthrough using a microstrip to stripline to conductor backed coplanar waveguide (CBCWG) design was investigated for microwave performance. The feedthrough was manufactured using a high-temperature cofired multilayer ceramic process. The study was instigated from the need to have a field-replaceable, Ku-band transmit/receive module as part of an existing DARPA MIMIC program. The result is a feedthrough capable of transmitting microwave frequencies to 24 GHz with acceptable loss characteristics. The feedthrough performance exceeds published results.<> View full abstract»

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  • Use of self bias to improve power saturation and intermodulation distortion in CW class B HBT operation

    Publication Year: 1992 , Page(s): 174 - 176
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (198 KB)  

    It is shown that a DC base bias circuit can be used to control the RF performance of a heterojunction bipolar transistor (HBT) operating under CW conditions near class B mode. By a careful choice of base bias resistance, gain can be linearized, output power at 1-dB gain compression increased, and intermodulation distortion reduced. Measurements performed on HBTs biased near class B operation showed a 10-dB improvement in 1-dB gain compression point and a 10-dB reduction in intermodulation distortion for moderate power levels. Results for various values of DC base resistance for a typical HBT are presented.<> View full abstract»

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  • A pulsed microwave oscillator using optically controlled active feedback

    Publication Year: 1992 , Page(s): 177 - 179
    Cited by:  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (209 KB)  

    An optically controlled microwave oscillator is demonstrated using MMIC compatible design techniques. The oscillator uses an optically controlled active inductor as a tunable feedback element in a two-port common gate FET circuit configuration. Experimental results are presented for a pulsed mode of operation that is triggered by illuminating the active feedback circuit.<> View full abstract»

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  • Full-wave analysis of a lossy rectangular waveguide containing rough inner surfaces

    Publication Year: 1992 , Page(s): 180 - 181
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (172 KB)  

    The full-wave mode-matching method employing the similarity transformation is used to derive the eigenvalue equation for the periodic bumpy regions that model the surface roughness of a WR-10 (75-110-GHz) waveguide. For the case study reported, attenuation losses increased by approximately 60% (36%) at 75 GHz (110 GHz).<> View full abstract»

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  • Scattering solution of three-dimensional array of patches using the recursive T-matrix algorithms

    Publication Year: 1992 , Page(s): 182 - 184
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (206 KB)  

    The recursive T-matrix algorithms are used to solve for the vector electromagnet scattering problem of a three-dimensional array of patches. The formulation uses only the E/sub x/ and E/sub y/ components of the electromagnetic field wherein the three-dimensional scalar addition theorem can be used. The coefficients for the scalar addition theorem are calculated with an efficient recurrence relation. This results in reduced memory requirements and computation time. When the addition theorem is violated, a generalized recursive T-matrix algorithm is used to mitigate the problem caused by the violation of the addition theorem. The scattering solutions are validated by comparison with the method of moments, and the reduced computational complexity of the solution is demonstrated.<> View full abstract»

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  • Analysis of dual-frequency stacked patch antennas using subsectional bases

    Publication Year: 1992 , Page(s): 185 - 187
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (215 KB)  

    The analysis of stacked, microstrip patches for dual-frequency antenna applications is performed by the method of moments applied in the spatial domain and using simple, subsectional basis functions. The moment matrix is filled, and solved, quickly by exploiting symmetries and performing all computations in four-byte, single precision. The use of subsectional bases allows applications to microstrip structures of arbitrary shapes. Resonant frequencies and reflection coefficients of two stacked patches are predicted well by linear systems of surprisingly low order.<> View full abstract»

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  • Novel symmetrical three-branch optical waveguide with equal power division

    Publication Year: 1992 , Page(s): 188 - 190
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (175 KB)  

    Symmetrical three-branch optical waveguide structures, which can divide power equally at each branch, are proposed from calculations by the beam propagation method. The structures are constructed with a triangular spacing area in the central branch to control the transmission coefficient between each branch and the main waveguide. The proposed three-branch waveguides can be easily designed due to their simple configuration.<> View full abstract»

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  • Characterization of picosecond pulse propagation in a microstrip line divider

    Publication Year: 1992 , Page(s): 191 - 193
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (188 KB)  

    Many extremely broad bandwidth circuit components have to be newly developed for practical applications of ultrashort electrical pulses. Theoretical and experimental investigations of the transmission properties of picosecond pulses through a microstrip line divider are reported. Full-wave analysis results in the frequency domain are incorporated into a Fourier transform algorithm for computer simulations of pulse propagation through a 3-dB microstrip line divider with a curved-line branching circuit pattern. Excellent agreement has been found between the theoretical predictions and the results of experimental measurements.<> View full abstract»

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  • Ultra low-noise performance of 0.15-micron gate GaAs MESFET's made by direct ion implantation for low-cost MMIC's applications

    Publication Year: 1992 , Page(s): 194 - 195
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (157 KB)  

    The high-speed and noise performance of 0.15- mu m gate GaAs MESFETs for microwave and millimeter-wave IC applications is reported. The best extrinsic f/sub t/ is 109 GHz without correction for pad parasitics, which is equivalent to an intrinsic f/sub t/ of 134 GHz. The 0.15- mu m*200- mu gate GaAs MESFET achieved a 0.6-dB noise figure with a 17-dB associated gain at 10 GHz and a 0.9-dB noise figure with a 13-dB associated gain at 18 GHz. The measured noise figure and associated gain are the best reported for GaAs MESFETs and are comparable to the best noise/gain performance of HEMTs and P-HEMTs.<> View full abstract»

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  • RCS reduction for a microstrip antenna using a normally biased ferrite substrate

    Publication Year: 1992 , Page(s): 196 - 198
    Cited by:  Papers (10)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (163 KB)  

    It is shown that the radar cross section (RCS) of a microstrip antenna can be significantly reduced over a broad frequency range by using a ferrite substrate biased to a cutoff state. When unbiased, the antenna operates in its usual fashion, with relatively large RCS peaks at frequencies corresponding to the resonances of the patch element. When the ferrite substrate is properly biased, the antenna element becomes effectively short-circuited, resulting in the elimination of the resonant behavior of the scattering response of the patch and in a reduction of 20-40 dB in its RCS. This mechanism allows the implementation of a microstrip antenna or array system that can be switched to an 'off' state, where it will be much less visible to an interrogating radar. Calculated results are obtained from a full-wave moment method solution for the RCS of a microstrip antenna on a normally biased ferrite substrate.<> View full abstract»

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  • Comments on 'Rapid pulsed microwave propagation' (and reply)

    Publication Year: 1992 , Page(s): 199 - 200
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (218 KB)  

    For the original article see ibid., vol.1, no.12, p.374-5 (1991). The commenter attempts to refute the claim by the authors of the above-titled paper that their measurements reveal microwaves propagating faster than the velocity of light. The authors defend their observations.<> View full abstract»

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  • Comments on 'Rapid pulsed microwave propagation' (and reply)

    Publication Year: 1992 , Page(s): 200 - 204
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (448 KB)  

    For the original article see ibid., vol.1, no.12, p.374-5 (1991). The commenters point out several errors in a paper by G.C. Giakos and T.K. Ishii in which they claim to have developed conclusive laboratory evidence that demonstrates microwave pulse propagation in waveguides, and in air, at velocities exceeding that of light. The authors defend their observations.<> View full abstract»

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  • Comments on 'Rapid pulsed microwave propagation' (and reply)

    Publication Year: 1992 , Page(s): 204 - 206
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (228 KB)  

    For the original article see ibid., vol.1, no.12, p.374-5 (1991). The commenter argues that the results reported by G.C. Giakos and T.K. Ishii in the above-titled paper of microwave propagation exceeding the speed of light contradict Maxwell's equations. Limitations of the experiment are examined. The authors defend their results.<> View full abstract»

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Aims & Scope

This Periodical ceased production in 2000. The current retitled publication is IEEE Microwaves and Wireless Component Letters.

Full Aims & Scope