Engineering topics
Publications and source records attributed to Mehdi, I..
This talk will focus on the technology that is being developed to enhance and extend planar integrated Schottky devices and circuits to meet mission local oscillator requirements.
Low-noise broad IF band 240 GHz subharmonically pumped planar Schottky diode mixers for space-borne radiometers have been developed and characterized.
This paper reports on the first all solid-state two-diode subharmonically pumped (SHP) mixer operating at 640 GHz.
The design and performance of a 640 GHz solid-state receiver using a fundamental planar-Schottky-diode mixer, InP Gunn diode oscillator, whisker-contacted Schottky-varactor-diode sextupler and folded-Fabry-Perot diplexer are reported.
We report on the performance of power amplifiers as local oscillator drivers for millimeter and submillimeter-wave receivers.
Planar submillimeter circuits are slowly replacing whisker-contacted devices at frequencies above 100 GHz, but in many cases the size constraints brought on by the short wavelengths associated with high frequency operation have not been adequeately addressed. Also, reproducibility becomes more important as we make the transition from tunable, whisker-based circuits to more monolithic designs. We are continuing to develop new circuites with more reproducible characteristics.
We report on a subharmonic mixer with a broad IF bandwidth that has been developed for the Microwave Instrument for the Rosetta Orbiter (MIRO) to study water transition lines occurring near 557 GHz.
Accelerated lifetime tests have been performed on intergrated planar GaAs Schottky diodes that were bonded to quartz substrates up-side-down with a heat-cured epoxy.
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The design and analysis of varactor diode doubler, quadrupler and cascaded doubler circuits for 320 and 640 GHz have been completed. A new approach has been employed to produce a tunerless waveguide mount with a very flexible, frequency scaleable, MMIC style multiplier circuit. The concept, design, predicted performance and measurements on some of the constituent mount elements are presented.
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We report on the first planar two-diode subharmonic mixer operating at 600MGHz.
A 210 MHz waveguide subharmonically-pumped mixer with integrated antiparallel-pair planar.
A T-gate-like structure has been developed, fabricated and tested as the anode for millimeter and submillimeter-wave Schottky diodes. The low parasitics of the T-anode diodes yield extremely high cutoff frequencies, making the diodes useable at frequencies well beyond 1 THz. The diodes were tested as an antiparallel-pair, integrated monolithically with microstrip circuitry on a quartz substrate, in a subharmonically pumped waveguide mixer. A double sideband noise temperature of 600 K with a conversion loss of 4.7 dB were measured at 200 GHz. This is believed to be the lowest noise temperature ever reported for a room temperature subharmonically-pumped Schottky diode mixer at this frequency.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.