An assessment of technology alternatives for telecommunications and information management for the space exploration initiative

On the 20th anniversary of the Apollo 11 lunar landing, President Bush set forth ambitious goals for expanding human presence in the solar system. The Space Exploration Initiative (SEI) addresses these goals beginning with Space Station Freedom, followed by a permanent return to the Moon, and a manned mission to Mars. A well designed, adaptive Telecommunications, Navigation, and Information Management (TNIM) infrastructure is vital to the success of these missions. Utilizing initial projections of user requirements, a team under the direction of NASA's Office of Space Operations developed overall architectures and point designs to implement the TNIM functions for the Lunar and Mars mission scenarios. Based on these designs, an assessment of technology alternatives for the telecommunications and information management functions was performed. This technology assessment identifies technology developments necessary to meet the telecommunications and information management system requirements for SEI. Technology requirements, technology needs and alternatives, the present level of technology readiness in each area, and a schedule for development are presented

A compact ka-band active integrated antenna with a GaAs amplifier in a ceramic package

This letter presents the design of a Ka-band active integrated antenna in package (AIAiP). A monolithic microwave integrated circuit amplifier based on the GaAs process and a compact patch antenna based on the printed circuit board process are implemented, respectively. Then, the amplifier and antenna are assembled together in a specified package using the wire-bond process. Thus, compared to the traditional solutions, the transmission loss and the size of the proposed AIAiP are significantly reduced. Furthermore, the influence of the bonding wire and the package is taken into account in the design of the amplifier and the antenna, respectively. A good agreement between the simulation and measurement results can be observed. The proposed AIAiP occupies a compact size of 7 × 7 mm2. Meanwhile, it achieves -10-dB impedance bandwidth from 33.4 to 37.2 GHz and a peak gain of 18.9 dBi at 35 GHz. Additionally, the impact of the package size on the antenna performance has been demonstrated for future AIA designers

Antennas for mobile satellite communications

A NASA sponsored program, called the Mobile Satellite (MSAT) system, has prompted the development of several innovative antennas at L-band frequencies. In the space segment of the MSAT system, an efficient, light weight, circularly polarized microstrip array that uses linearly polarized elements was developed as a multiple beam reflector feed system. In the ground segment, a low-cost, low-profile, and very efficient microstrip Yagi array was developed as a medium-gain mechanically steered vehicle antenna. Circularly shaped microstrip patches excited at higher-order modes were also developed as low-gain vehicle antennas. A more recent effort called for the development of a 20/30 GHz mobile terminal antenna for future-generation mobile satellite communications. To combat the high insertion loss encountered at 20/30 GHz, series-fed Monolithic Microwave Integrated Circuit (MMIC) microstrip array antennas are currently being developed. These MMIC arrays may lead to the development of several small but high-gain Ka-band antennas for the Personal Access Satellite Service planned for the 2000s

Radar cross section studies

The ultimate goal is to generate experimental techniques and computer codes of rather general capability that would enable the aerospace industry to evaluate the scattering properties of aerodynamic shapes. Another goal involves developing an understanding of scattering mechanisms so that modification of the vehicular structure could be introduced within constraints set by aerodynamics. The development of indoor scattering measurement systems with special attention given to the compact range is another goal. There has been considerable progress in advancing state-of-the-art scattering measurements and control and analysis of the electromagnetic scattering from general targets

Radiometer-on-a-chip: a path toward super-compact submillimeter-wave imaging arrays

A novel approach for submillimeter-wave heterodyne imaging arrays is presented in this paper. By utilizing diverse technologies such as GaAs membrane based terahertz diodes, wafer bonding, bulk Si micromachining, micro-lens optics, and CMOS 3-D chip architectures, a super-compact low-mass submillimeter-wave imaging array is envisioned. A fourwafer based silicon block for a working W-band power amplifier MMIC is demonstrated. This module drastically reduces mass and volume associated with metal block implementations without sacrificing performance. A path towards super compact array receivers in the 500-600 GHz range is described in detail

System-Level Integrated Circuit (SLIC) development for phased array antenna applications

A microwave/millimeter wave system-level integrated circuit (SLIC) being developed for use in phased array antenna applications is described. The program goal is to design, fabricate, test, and deliver an advanced integrated circuit that merges radio frequency (RF) monolithic microwave integrated circuit (MMIC) technologies with digital, photonic, and analog circuitry that provide control, support, and interface functions. As a whole, the SLIC will offer improvements in RF device performance, uniformity, and stability while enabling accurate, rapid, repeatable control of the RF signal. Furthermore, the SLIC program addresses issues relating to insertion of solid state devices into antenna systems, such as the reduction in number of bias, control, and signal lines. Program goals, approach, and status are discussed

Advanced automotive radar front-end based on gapwaveguide technology

The pursuit of higher levels of autonomous driving necessitates the utilization of advanced radar sensors that possess improved environmental perception capabilities. Consequently, next-generation automotive radars require sophisticated antenna systems with high efficiency, thereby making waveguide antennas a more viable choice. In this context, it has been observed that gapwaveguides exhibit superior performance in comparison to traditional waveguides, particularly in terms of assembly reliability, when employed in the development of multi-layer waveguide antennas. Within the scope of this thesis, the primary objective is to comprehensively explore the design of front-ends for cutting-edge automotive radar sensors by leveraging the potential of gapwaveguide technology. The initial aspect of this thesis involves an exploration of integration techniques capable of achieving high performance in waveguide-based RF front-ends. In particular, the thesis introduces novel vertical gapwaveguide-to-microstrip transitions that facilitate the integration of RF front-ends featuring multi-layer configurations. Furthermore, this thesis introduces radar transceivers equipped with built-in waveguide-to-microstrip transitions, known as launcher-in-package, along with an imaging radar antenna featuring customized interconnections explicitly designed utilizing gapwaveguide technology to interface with the transceivers.Secondly, in light of the utilization of radar sensors incorporating orthogonal dual polarizations on the transmitting and/or receiving ends, an opportunity arises to acquire polarimetric information from the surrounding environment, thereby representing a promising advancement in the realm of autonomous driving. This thesis presents novel antenna designs based on gapwaveguide technology for polarimetric radar sensors. An 8$\times$8 planar array utilizing double grooved circular waveguide polarizers is introduced, specifically designed for fixed beam, high gain polarimetric sensing applications. In addition, this thesis presents a polarimetric radar sensor that utilizes a MIMO configuration featuring single-CP transmitting antennas and dual-CP receiving antennas. The antenna design incorporates series-fed septum polarizers, which offer low-profile characteristics.In summary, this thesis undertakes a comprehensive investigation into the designs of advanced automotive radar front-ends utilizing gapwaveguide technology. The study explores the advancements in terms of integration techniques and polarimetric capability, demonstrating the potential of gapwaveguide technology for the practical implementation of waveguide-based RF front-ends. The utilization of such front-ends can significantly enhance the capabilities of autonomous driving systems