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  • 1
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-18
    Description: The SPS transmitting array requires an architecture which will provide a low weight, high efficiency and high structural rigidity. As noted above, waveguide slot arrays constitute the most desirable option. Consequently, such an array has been chosen for the SPS. Waveguide slot arrays offer high efficiency, uniform illumination, are are fairly lighweight. Bandwidths of such arrays are narrow, typically 1/2-2%. Although this does not directly impact the SPS, which transmits power at a single frequency of 2.45 GHz, the narrow bandwidth does constrain the thermal and mechanical tolerances of the antenna. The purpose of this program is to better define the electronic aspects of an SPS specific waveguide slot array. The specific aims of the program are as follows: (1) To build a full-scale half-module, 10 stick, array, the design parameters for which are to be determined by analytical considerations tempered by experimental data on a single slotted radiating stick, (2) To experimentally evaluate the completed array with respect to antenna pattern, impedance and return loss, and (3) To measure swept transmission amplitude and phase to provide a data base for design of a receiving antenna.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA. Johnson Space Center Workshop on Microwave Power Transmission and Reception; p 180-187
    Format: text
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  • 2
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-18
    Description: The SPS transmitting array requires an architecture which will provide a low weight, high efficiency and high structural rigidity. Waveguide slot arrays constitute the most desirable option. Consequently, such an array was chosen for the SPS. Waveguide slot arrays offer high efficiency, uniform illumination, and are fairly lightweight. Bandwidths of such arrays are narrow, typically 1/2-2%. Although this does not directly impact the SPS, which transmits power at a single frequency of 2.45 GHz, the narrow bandwidth does constrain the thermal and mechanical tolerances of the antenna. The purpose of this program is to better define the electronic aspects of an SPS specific waveguide slot array. The specific aims of the program are as follows: (1) To build a full-scale half-module, 10 stick, array, the design parameters for which are to be determined analytical considerations tempered by experimental data on a single slotted radiating stick, (2) To experimentally evaluate the completed array with respect to antenna pattern, impedance and return loss; and (3) To measure swept transmission amplitude and phase to provide a data base for design of a receiving antenna.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA. Johnson Space Center Workshop on Microwave Power Transmission and Reception 158-165 (SEE N82-12538 03-44)
    Format: text
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  • 3
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-18
    Description: The most likely compact configuration to realize both high efficiency and high gain is a 5-6 cavity design focused by an electromagnet. An outline of a potential klystron configuration is given. The selected power output of 70 kW CW resulted from a maximum assumed operating voltage of 40 kV. The basic klystron efficiency cannot be expected to exceed 70-75% without collector depression. Although impressive gains were achieved in raising the basic efficiency from 50% to 70% or so with a multi-stage collector, the estimated efficiency improvement due to 5-stage collector at the 75% level is only about 8% resulting in an overall efficiency of about 83%.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA. Johnson Space Center Workshop on Microwave Power Transmission and Reception; p 127-136
    Format: text
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  • 4
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-18
    Description: Fiber optic technology was selected in the SPS baseline design to transmit a stable phase reference throughout the microwave array. Over a hundred thousand microwave modules are electronically steered by the phase reference signal to form the power beam at the ground receiving station. The initially selected IF distribution frequency of the phase reference signal was set at 980 MHz or a submultiple of it. Fiber optics offers some significant advantages in view of the SPS application. Optical transmission is highly immume to EMI/RFI, which is expected to be severe when considering the low distribution power. In addition, there will be savings in both mass, physical size, and potentially in cost.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA. Johnson Space Center Workshop on Microwave Power Transmission and Reception; p 110-114
    Format: text
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  • 5
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-18
    Description: The computer programming efforts were directed primarily to beam pattern analysis. The computer programs used for simulation provide: verification of the reference design; definition of feasible departures such as quantized distributions; the study of far-out sidelobe roll-off characteristics; the analysis of errors and failures; illumination function analysis to develop beam patterns for efficient collection; and beam shaping synthesis to meet environmental constraints.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA. Johnson Space Center Workshop on Microwave Power Transmission and Reception; p 14-23
    Format: text
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  • 6
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: The most likely compact configuration to realize both high efficiency and high gain (approx. 40 dB) is a 5-6 cavity design focused by an electromagnet. The basic klystron efficiency cannot be expected to exceed 70-75% without collector depression. It was estimated that the net benefit of a 5 stage collector over a 2 stage collector is between 1.5 and 3.5 kW per tube. A modulating anode is incorporated in the design to enable rapid shutoff of the beam current in case the r.f. drive should be removed.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA. Johnson Space Center Solar Power Satellite Microwave Transmission and Reception; p 175-184
    Format: application/pdf
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  • 7
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: Three types of computer simulations were developed to study the SPS microwave power transmission system (MPTS). The radially symmetric array simulation is low cost and is utilized to investigate general overall characteristics of the spacetenna at the array level only. "Tiltmain", a subarray level simulation program, is used to study the effects of system errors which modify the far-field pattern. The most recently designed program, "Modmain," takes the detail of simulation down to the RF module level and so to date is the closest numerical model of the reference design.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA. Johnson Space Center Solar Power Satellite Microwave Transmission and Reception; p 33-42
    Format: application/pdf
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  • 8
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: Fiber optic technology was tentatively selected in the SPS baseline design to transmit a stable phase reference throughout microwave array. Over a hundred thousand microwave modules are electronically steered by the phase reference signal to form the power beam at the ground receiving station. The initially selected IF distribution frequency of the phase reference signal was at 980 MHz or a submultiple of it. Fiber optics offers some significant advantages in view of the SPS application. Optical transmission is highly immune to EMI/RFI, which is expected to be severe when considering the low distribution power. In addition, there are savings in both mass, physical size, and potentially in cost.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA. Johnson Space Center Solar Power Satellite Microwave Transmission and Reception; p 154-158
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  • 9
    Publication Date: 2016-06-07
    Description: Several candidate antenna configurations are evaluated in terms of weight, efficiency, and structural rigidity. Particular emphasis is given to the waveguide slot array and its application to solar power satellites SPS. The electronic aspects of an SPS specific waveguide slot array are defined.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA. Johnson Space Center Solar Power Satellite Microwave Transmission and Reception; p 227-234
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  • 10
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: The design of the microwave system for the solar power satellite is described. Design modifications recommended include changes in phase control to the power module level, a reduction in allowable amplitude jitter, the use of metal matrix waveguides, and sequences for startup/shutdown procedures. Investigations into reshaping the beam pattern to improve overall rectenna collection efficiency and improve sidelobe control are surveyed.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA, Washington The Final Proc. of the Solar Power Satellite Program Rev.; p 277-280
    Format: application/pdf
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