ISSN:0895-2477    

DOI:10.1002/mop.4650040102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractTechnology is now becoming available to develop submillimeter‐wavelength heterodyne radiometric experiments for remote sensing the upper atmosphere from space. Such experiments can provide many essential measurements for assessing and critically monitoring the depletion of stratospheric ozone by pollution from industrial products. A millimeter‐wavelength experiment for this purpose is now ready for launch on the NASA Upper Atmosphere Research Satellite (UARS). An enhanced version of the UARS experiment, which operates at submillimeter wavelengths, is under investigation for the future NASA Earth Observing Sys

ISSN:0895-2477    

DOI:10.1002/mop.4650040103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractWe have improved the aperture efficiency of silicon integrated‐circuit horn antennas by optimizing the length of the dipole probes and by coating the entire horn walls with gold. To make these measurements, we developed a new thin‐film power‐density meter for measuring power density with accuracies better than 5%. The measured aperture efficiency improved from 44% to 72% at 93 GHz. This is sufficient for use in many applications which now use machined waveguide

ISSN:0895-2477    

DOI:10.1002/mop.4650040104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractWe describe a planar antenna structure consisting of two half‐wave dipoles, which are backed by a metallic reflector to create an image of two more elements. The array produces rather a wide main beam, and is therefore used with a dielectric lens. The far‐field pattern of the dipole liens antenna has cross‐pol better than −20 dB, and side lobes below −13 dB over an octave band. The impedance at the feedpoint of the antenna is approximately 70 ‐ j10 Ω at the center

ISSN:0895-2477    

DOI:10.1002/mop.4650040105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractA high‐gain monolithic millimeter‐wave antenna has been designed, fabricated and tested at 222 GHz. The structure consists of a traveling‐wave antenna integrated on a 1.2‐μm dielectric membrane and suspended in a longitudinal cavity etched in a silicon wafer. A new traveling‐wave antenna design yields a wideband input impedance and a low cross‐polarization component in the E‐ and quasi‐H‐plane patterns. A directivity of 17.7 dB and a main‐beam efficiency of 88.5% are calculated from the 222‐GHz pattern measurements. The integrated corner‐reflector antenna is well suited for millimeter‐and submillimeter‐wave imaging applicatio

ISSN:0895-2477    

DOI:10.1002/mop.4650040106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe twin slot antenna on a dielectric stack should find application in the far‐infrared spectral region. We present measurements at 94 GHz which show that this antenna will be useful as an imaging element.Based on these results, in combination with a new detector element, a two‐dimensional FIR imaging array is propo

ISSN:0895-2477    

DOI:10.1002/mop.4650040107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractAdvances in high‐frequency resonant‐tunneling‐diode (RTD) oscillators are described. Oscillations up to a frequency of 420 GHz have been achieved in the GaAs/AlAs system. Recent results obtained with In0.53Ga0.47As/AlAs and InAs/AlSb RTDs show a greatly increased power density and indicate the potential for fundamental oscillations up to about 1 THz. These results are consistent with a lumped‐element equivalent circuit model of the RTD. The model shows that the maximum oscillation frequency of the GaAs/AlAs RTDs is limited primarily by series resistance, and that the power density is limited by low peak‐to‐valley cu

ISSN:0895-2477    

DOI:10.1002/mop.4650040108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe potential and capabilities of tunnel transit‐time (TUNNETT) devices for power generation in the 100‐1000 GHz range are presented. The basic properties of these devices and the important material parameters which determine their properties are discussed and criteria for designing such devices are presented. It is shown from a first‐order model that significant amounts of power can be obtained from these devices in the terahertz frequency

ISSN:0895-2477    

DOI:10.1002/mop.4650040109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractExtensive studies on the theoretical performance of Schonky‐varactors and varistors as multipliers of a frequency around 100 GHz to the submillimeter region (400‐1200 GHz) in various direct and cascaded configurations have been carried out using harmonic balance analysis. Because of high circuit losses (≥10 dB) in a multiplier chain producing 1 THz, the output power seems to stay at or below 100 μW even in the best multiplier configurations when the available input power at 100 GHz is

ISSN:0895-2477    

DOI:10.1002/mop.4650040110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractQuantum‐well diodes have been used for generating power at millimeter and submillimeter waves, both in negative resistance oscillators and in multipliers. In this article, we will first discuss the power versus frequency and the maximum frequency of oscillation of “ordinary” quantum‐well oscillators. Possible methods of improving the power output and the maximum frequency of oscillation will be suggested. Quantum‐well diode multipliers will also be discussed. Realizing the importance of the nonlinear capacitance for the quantumwell diode multiplier efficiency, we have investigated a quantum‐barrier diode in multiplier a

ISSN:0895-2477    

DOI:10.1002/mop.4650040111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY