| 1. |
- Gevorgian, Spartak, 1948, et al.
(author)
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Asymmetric Coplanar-Strip Transmission Lines for MMIC and Integrated Optic Applications
- 1990
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In: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 26:22, s. 16 - 1918
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Journal article (peer-reviewed)abstract
- Microwave transmission lines with coplanar electrodes on dielectric or semiconductor substrates are widely used in integrated optic travelling-wave modulators and optical control microwave attenuators/modulators. The reduction of the drive voltage in travelling-wave modulators and control power in optical control microwave attenuators is achieved by reducing the width of the gap between the coplanar strips. When reducing the gap width in these devices special care must be taken to keep the characteristic impedance, Z0, high. Although symmetric coplanar and coplanar-strip waveguides, have been used, asymmetric coplanar-strip waveguides seem to be highly flexible in practical device design. Along with small sizes, the impedance, Z0, effective dielectric constant, in e, and microwave refractive index, nm, can be adjusted by changing the width of one of the strips while keeping the width of the other strip and of the gap fixed. The basic parameters ( in e,C,Z0) of asymmetric coplanar-strip waveguides on finite thickness substrate are reported.
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| 2. |
- Gevorgian, Spartak, 1948
(author)
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Basic characteristics of two layered substrate coplanar waveguides
- 1994
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In: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 30:15, s. 1236 - 1237
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Journal article (peer-reviewed)abstract
- The conformal mapping technique is used to obtain simple CAD oriented closed form expressions for the effective dielectric permittivity, line capacitance and impedance of two layered coplanar waveguides (CPWs)
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| 3. |
- Gevorgian, Spartak, 1948
(author)
-
Microwave Conductivity of Optically Excited Gap in a Semiconductor Microstrip
- 1990
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In: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 26:22, s. 1921 - 1922
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Journal article (peer-reviewed)abstract
- A simple expression for the microwave conductance of an optically excited gap in a semiconductor microstrip is presented. For small gap widths the performance of photoconductive detectors or optical control microwave switches is limited by the contact resistance
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| 4. |
- Goobar, E., et al.
(author)
-
Broadband measurements of frequency noise spectrum in two section DBR laser
- 1991
-
In: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 27, s. 289-291
-
Journal article (peer-reviewed)abstract
- The dependence of the frequency noise on the output power, the tuning current and the current modulation has been measured in a two electrode DBR laser from 30 MHz to 8 GHz. The frequency noise spectrum was fairly flat and decreased with increased output power at a rate faster than 1/P. At certain biasing levels, the noise increased and the relaxation peak was shifted towards lower frequencies when current was injected into the passive waveguide. Furthermore, the frequency noise was not affected by the current modulation.
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| 5. |
- Gudmundson, Mikael
(author)
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Correlation Model for Shadow Fading in Mobile Radio Systems
- 1991
-
In: Electronics Letters. - : IEEE. - 0013-5194 .- 1350-911X. ; 27:23, s. 2145-2146
-
Journal article (peer-reviewed)abstract
- A simple autocorrelation model for shadow fading in mobile radio channels is proposed. The model is fitted to both large cells and microcells. Results show that the model fit is good for large to moderate cell sizes. It is however shown that the model does not provide adequate results for microcells.
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| 6. |
- HELMFRID, S, et al.
(author)
-
STIMULATED-EMISSION IN ER-TI-LINBO3 CHANNEL WAVE-GUIDES CLOSE TO 1.53-MU-M TRANSITION
- 1991
-
In: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 27, s. 913-914
-
Journal article (peer-reviewed)abstract
- Fabrication and characterisation of Er:Ti:LiNbO3 channel waveguides is reported. A lifetime of 2.4 +/- 0.2 ms has been measured for the 4I13/2 level. In a pump and probe experiment using a high power InGaAsP laser and a tunable DBR laser, a signal increase of 0.75 dB for a transmitted pump power of 4.8 mW was demonstrated.
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| 7. |
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| 8. |
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| 9. |
- Nilsson, Peter, et al.
(author)
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CMOS on-chip clock for digital signal processors
- 1993
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In: Electronics Letters. - Stevenage, UK : IET. - 0013-5194 .- 1350-911X. ; 15:8, s. 669-670
-
Journal article (peer-reviewed)abstract
- An on-chip clock for frequencies up to 190 MHz is presented. This clock generator can be used for application specific digital signal processors which are clocked faster than the off-chip system clock. It is useful for both processors with a few cycles per sample or for high frequency bit-serial processors which need a large number of cycles.
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| 10. |
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| 11. |
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| 12. |
- Zander, Jens, et al.
(author)
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Capacity allocation and channel assignment in cellular radio systems using reuse partitioning
- 1992
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In: Electronics Letters. - : IEEE. - 0013-5194 .- 1350-911X. ; 28:5, s. 438-440
-
Journal article (peer-reviewed)abstract
- Reuse partitioning is a technique for providing more efficient spectrum reuse in cellular radio systems. A cell in such a system is divided into concentric zones, each associated with an overlaid cell plan. For these schemes an optimum channel assignment strategy is proposed. Numeric examples show capacity improvements of about 50% compared to conventional systems.
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| 13. |
- Zander, Jens
(author)
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Slotted ALOHA multihop packet radio networks with directional antennas
- 1990
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In: Electronics Letters. - : IEEE. - 0013-5194 .- 1350-911X. ; 26:25, s. 2098-2100
-
Journal article (peer-reviewed)abstract
- The use of directional antennas in multihop packet radio networks using slotted ALOHA access is considered. Tractable approximations to the network performance in terms of expected forward progress are derived. Results show that packet collisions can be strongly reduced already with moderate gain antennas to allow for a substantial increase in network performance.
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| 14. |
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