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An inflatable Ka-band three-meter reflectarray is being developed to achieve low mass and small launch-vehicle stowage volume for future deep-space spacecraft telecommunication antenna applications.
Inflatable antenna technology is being developed by JPL/NASA to enable the capabilities of low-mass, high packaging efficiency, and low-cost deployment for future spacecraft high-gain antennas. One of the technologies being studied is the inflatable microstrip reflectarray.
The microstrip reflectarray has been identified as one of the enabling technologies to achieve low mass, conformal mounting, wide-angle beam scanning, etc. for NASA's future speceborne high-gain antennas.
ct given. Paper discusses antennas in general, and a new microstrip reflectarray antenna, and its better performance than parabolic, or other types.
This paper presents the structural and mechanical development of a 7-meter inflatable/self-rigidizable reflectarray antenna that is intended for space communication applications.
This paper describes a large dual-beam, dual polarized Ka-Band reflectarray antenna prototype which was developed to demonstrate that key requirements of a space borne interferometric radar altimeter are achievable. The antenna consists of a 2.5 x 0.26 m aperture comprised of a rectangular grid of square patch printed circuit elements. The 2.6 m focal length offset-fed reflector is illuminated by a waveguide slot array feed focused in the nearfield. Measured results show good agreement with gain and radiation pattern predictions and demonstrates >50% aperture efficiency.
A printed reflectarray is an antenna similar to a parabolic reflector, but with its reflecting surface capable of being designed either flat or slightly curved for conformal mounting onto an existing structure without adding significant amount of mass and volume to the structure.
This article presents an advanced antenna technology, namely the printed reflectarray, that has the potential for providing an enhanced communication capability with relatively low cost, small size and small mass. It has applicaiton in the commercial and military arenas as well as in space exploration.
Proposed microstrip reflectarray antenna provides two or more beams in different directions, without power-dividing circuitry. Because antenna flat, mass and cost of fabrication less than paraboloidal reflector with aperture of equal size, and mounted easier with less supporting structure. Designed to be mounted on ground or surfaces of ships, land vehicles, and buildings.
The present invention provides a High Resolution Scanning Reflectarray Antenna (HRSRA) for the purpose of tracking ground terminals and space craft communication applications. The present invention provides an alternative to using gimbaled parabolic dish antennas and direct radiating phased arrays. When compared to a gimbaled parabolic dish, the HRSRA offers the advantages of vibration free steering without incurring appreciable cost or prime power penalties. In addition, it offers full beam steering at a fraction of the cost of direct radiating arrays and is more efficient.
The Applied RF Technology Branch of the NASA Glenn Research Center, Cleveland, Ohio, has an on-going effort in the area of thin film ferroelectric technology for microwave applications. Particular attention has been given to developing ferroelectric phase shifters for the implementation and experimental demonstration of an electronically steerable reflectarray antenna. In the process of optimizing these material to fit the implementation requirements of the aforementioned antenna, we have accumulated a great deal of information and knowledge in areas such as the effect of the composition of the ferroelectric thin films on phase shifter performance, self assembled monolayers (SAMs) in the metallic/ferroelectric interface and their impact on phase shifter performance, correlation between microstructure and microwave properties, and the effect of selective etching on the overall performance of a thin film-ferroelectric based microwave component, amongst others. We will discuss these issues and will provide an up-dade of the current development status of the reflect-array antenna.
This paper will start from the reviewing of previous developments of the inflatable reflectarray antenna. Details of the current model will then be presented.
Gossamer space structures are relatively large, flimsy, and lightweight. As a result, they are more easily affected or degraded by space thermal environments compared to other space structures. This study examines the structural integrity of a three-meeter Ka-band inltable/self-rigidizable reflectarray antenna under space thermal environments.
The purpose of this paper is to investigate potential reflectarray elements by taking into consideration the eventual implementation of MEMS technology for this particular application and detailed characterization of one of the potential element designs.
We have developed relatively broadband K- and Ka-band phase shifters using synthetic (slow-wave) transmission lines employing coupled microstripline "varactors". The tunable coupled microstripline circuits are based on laser ablated BaSrTiO films on lanthanum aluminate substrates. A model and design criteria for these novel circuits will be presented, along with measured performance including anomalous phase delay characteristics. The critical role of phase shifter loss and transient response in reflectarray antennas will be emphasized.
While the capabilities of CubeSats have greatly increased in the past years, large, deployable high frequency apertures remain a limitation. The goal of this work is to develop a large 1 meter antenna operating at 35.75 GHz for RADAR applications. A reflectarray design was selected, as the flat panels are compatible with the CubeSat form factor. A center-fed, Cassegrain configuration was selected for the feed, to minimize deployed height. The flat panel configuration and Cassegrain feed allowed the entire 1 meter antenna to be compatible with a 6U bus, leaving a little under 4U of volume for remaining instrument and spacecraft components. Several iterations of the design have been built and tested, with an RF test of a fully deployed assembly being completed most recently. Prior to constructing the flight model, another iteration will need to be built and tested. The goal is to have the antenna flight ready before 2020.
While the capabilities of CubeSats have greatly increased in the past years, large, deployable high frequency apertures remain a limitation. The goal of this work was to develop a large 1 meter antenna operating at 35.75 Ghz for RADAR applications. A reflectarray design was selected, as the flat panels were compatible with the CubeSat form factor. A center-fed, Cassegrain configuration was selected for the feed, to minimize deployed height. The flat panel configuration and Cassegrain feed allowed the entire 1 meter antenna to be compatible with a 6U bus, leaving a little under 4U of volume for remaining instrument and spacecraft components. Several iterations of the design have been built and tested, with an RF test of a fully deployed assembly being completed most recently. The goal is to have the antenna flight ready before 2020.
This paper presents a novel flexure design for small scale refelectarrays, specifically CubeSats, that requires high level of deployment precision. Advantages of using a HSC flexure includes additional thermal stability, lesser part count and passive deployment mechanism using the stored strain energy. The proposed design is to use two flat HSC strips of thickness ℎ, length 2𝐿ℎ, width 𝑊ℎ that attach to the core-reflector panel interface. The flexure satisfies two main requirements: ability to fold to a specific compaction 𝑑 without material failure and sufficient stiffness in the deployed configuration. The elastica analysis was implemented to identify the maximum strains in the flexure when folded and provide relations that combine Δ, ℎ, 𝐿ℎ with the maximum allowable strain. A simplified analysis was performed of the vibration of a panel-flexure combination using a two degree of freedom system. The vibration analysis reveals a dimensionless length parameter 𝛽 = (𝐿ℎ/𝐿𝑃) (Δ/ℎ) that determines the transition between bending and shear modes. A non-dimensional relationship was obtained between the natural frequency and 𝛽 that captures the impact of each parameter on the response of the structure. Our current work involves fabricating and testing of the proposed flexures using High Strain Composite materials, with plans to build a prototype for a deployable reflectarray.