Advanced deep space communication systems study Final report

Deep space communication system requirements for period 1970 to 198

Figure of merit studies of beam power concepts for advanced space exploration

Surface to surface, millimeter wavelength beam power systems for power transmission on the lunar base were investigated. Qualitative/quantitative analyses and technology assessment of 35, 110 and 140 GHz beam power systems were conducted. System characteristics including mass, stowage volume, cost and efficiency as a function of range and power level were calculated. A simple figure of merit analysis indicates that the 35 GHz system would be the preferred choice for lunar base applications, followed closely by the 110 GHz system. System parameters of a 35 GHz beam power system appropriate for power transmission on a recent lunar base concept studied by NASA-Johnson and the necessary deployment sequence are suggested

Microwave performance characterization of large space antennas

Performance capabilities of large microwave space antenna configurations with apertures generally from 100 wavelengths upwards are discussed. Types of antennas considered include: phased arrays, lenses, reflectors, and hybrid combinations of phased arrays with reflectors or lenses. The performance characteristics of these broad classes of antennas are examined and compared in terms of applications

Massive MIMO is a Reality -- What is Next? Five Promising Research Directions for Antenna Arrays

Massive MIMO (multiple-input multiple-output) is no longer a "wild" or "promising" concept for future cellular networks - in 2018 it became a reality. Base stations (BSs) with 64 fully digital transceiver chains were commercially deployed in several countries, the key ingredients of Massive MIMO have made it into the 5G standard, the signal processing methods required to achieve unprecedented spectral efficiency have been developed, and the limitation due to pilot contamination has been resolved. Even the development of fully digital Massive MIMO arrays for mmWave frequencies - once viewed prohibitively complicated and costly - is well underway. In a few years, Massive MIMO with fully digital transceivers will be a mainstream feature at both sub-6 GHz and mmWave frequencies. In this paper, we explain how the first chapter of the Massive MIMO research saga has come to an end, while the story has just begun. The coming wide-scale deployment of BSs with massive antenna arrays opens the door to a brand new world where spatial processing capabilities are omnipresent. In addition to mobile broadband services, the antennas can be used for other communication applications, such as low-power machine-type or ultra-reliable communications, as well as non-communication applications such as radar, sensing and positioning. We outline five new Massive MIMO related research directions: Extremely large aperture arrays, Holographic Massive MIMO, Six-dimensional positioning, Large-scale MIMO radar, and Intelligent Massive MIMO.Comment: 20 pages, 9 figures, submitted to Digital Signal Processin

Phased array-fed antenna configuration study

The scope of this contract entails a configuration study for a phased array fed transmit antenna operating in the frequency band of 17.7 to 20.2 GHz. This initial contract provides a basis for understanding the design limitations and advantages of advanced phased array and cluster feeds (both utilizing intergral MMIC modules) illuminating folded reflector optics (both near field and focused types). Design parametric analyses are performed utilizing as constraints the objective secondary performance requirements of the Advanced Communications Technology Satellite (Table 1.0). The output of the study provides design information which serves as a data base for future active phased array fed antenna studies such as detailed designs required to support the development of a ground tested breadboard. In general, this study is significant because it provides the antenna community with an understanding of the basic principles which govern near field phased scanned feed effects on secondary reflector system performance. Although several articles have been written on analysis procedures and results for these systems, the authors of this report have observed phenomenon of near field antenna systems not previously documented. Because the physical justification for the exhibited performance is provided herein, the findings of this study add a new dimension to the available knowledge of the subject matter

Infrared Phased-array Antenna-coupled Tunnel Diodes

Infrared (IR) dipole antenna-coupled metal-oxide-metal (MOM) tunnel diodes provide a unique detection mechanism that allows for determination of the polarization and wavelength of an optical field. By integrating the MOM diode into a phased-array antenna, the angle of arrival and degree of coherence of received IR radiation can be determined. The angular response characteristics of IR dipole antennas are determined by boundary conditions imposed by the surrounding dielectric or conductive environment on the radiated fields. To explore the influence of the substrate configuration, single dipole antennas are fabricated on both planar and hemispherical lens substrates. Measurements demonstrate that the angular response can be tailored by the thickness of the electrical isolation stand-off layer on which the detector is fabricated and/or the inclusion of a ground plane. Directional detection of IR radiation is achieved with a pair of dipole antennas coupled to a MOM diode through a coplanar strip transmission line. The direction of maximum angular response is altered by varying the position of the diode along the transmission line connecting the antenna elements. By fabricating the devices on a quarter wave layer above a ground plane, narrow beam widths of 35° full width at half maximum and reception angles of ± 50° are achievable with minimal side-lobe contributions. Phased-array antennas can also be used to assess the degree of coherence of a partially coherent field. For a two-element array, the degree of coherence is a measure of the correlation of electric fields received by the antennas as a function of the element separation

Breaking FOV-Aperture Trade-Off with Multi-Mode Nano-Photonic Antennas

Nano-photonic antennas are one of the key components in integrated photonic transmitter and receiver systems. Conventionally, grating couplers, designed to couple into an optical fiber, suffering from limitations such as large footprint and small field-of-view (FOV) have been used as on-chip antennas. The challenge of the antenna design is more pronounced for the receiver systems, where both the collected power by the antenna and its FOV often need to be maximized. While some novel solutions have been demonstrated recently, identifying fundamental limits and trade-offs in nano-photonic antenna design is essential for devising compact antenna structures with improved performance. In this paper, the fundamental electromagnetic limits, as well as fabrication imposed constraints on improving antenna effective aperture and FOV are studied, and approximated performance upper limits are derived and quantified. By deviating from the conventional assumptions leading to these limits, high-performance multi-mode antenna structures with performance characteristics beyond the conventional perceived limits are demonstrated. Finally, the application of a pillar multi-mode antenna in a dense array is discussed, an antenna array with more than 95% collection efficiency and 170∘ FOV is demonstrated, and a coherent receiving system utilizing such an aperture is presented

Adaptive multibeam antennas for spacelab. Phase A: Feasibility study

The feasibility was studied of using adaptive multibeam multi-frequency antennas on the spacelab, and to define the experiment configuration and program plan needed for a demonstration to prove the concept. Three applications missions were selected, and requirements were defined for an L band communications experiment, an L band radiometer experiment, and a Ku band communications experiment. Reflector, passive lens, and phased array antenna systems were considered, and the Adaptive Multibeam Phased Array (AMPA) was chosen. Array configuration and beamforming network tradeoffs resulted in a single 3m x 3m L band array with 576 elements for high radiometer beam efficiency. Separate 0.4m x 0.4 m arrays are used to transmit and receive at Ku band with either 576 elements or thinned apertures. Each array has two independently steerable 5 deg beams, which are adaptively controlled

Refraction interference elimination employing smart arrays at VHF

Radio interference from the Middle East is one of the most significant problems plaguing the local radio services in Cyprus today. The issue is particularly noticeable on the highway, where it affects in-car tuners in all coastal areas of the island when the weather is hot and humid. In this work, the problem of interference from the Middle East was explored in the context of field strength variations versus the type of propagation mechanism favouring the radio waves in Band II, allowing them to travel from the Middle East to beyond the horizon in Cyprus. This problem was significant, since no line of sight exists between the two regions. After in-depth analysis adhering to the ITU (International Telecommunications Union) Recommendations, it was demonstrated that interference is caused by “Tropospheric Ducting”, i.e., trapping of the overseas transmitted signals between two layers of the troposphere at different heights. The upper air data were obtained using the Weather Research Forecasting (WRF-ARW version 3.4) model. The results yielded by the present study confirm that this model provides accurate prediction of interference for up to five days in advance. The interference problem is widely recognized, and therefore many attempts have been made to explicate its causes and provide solutions. The aim of the present study was to present a robust solution based on an innovative receiving antenna design. The antenna is a receiver’s component that collects electromagnetic waves from various directions. The rationale behind focusing on a circular array topology is that its tuning ensures that the receiver processes the desired signal only, while rejecting the unwanted interference. This can presently only be achieved by a large directional external antenna that must be steered mechanically in the desired direction. As this arrangement is not practical, an innovative smart antenna was proposed as an alternative. A circular phased array is a very compact antenna that produces a predicted radiation pattern, whereby it receives maximum energy from the desired direction without the need for mechanical control. Circular arrays exhibit high gain as well as immunity to interference, making them ideal for use in high interference environments. This combination allows the antenna to be incorporated into a commercial deck receiver or installed on vehicles

Breaking FOV-Aperture Trade-Off with Multi-Mode Nano-Photonic Antennas

Nano-photonic antennas are one of the key components in integrated photonic transmitter and receiver systems. Conventionally, grating couplers, designed to couple into an optical fiber, suffering from limitations such as large footprint and small field-of-view (FOV) have been used as on-chip antennas. The challenge of the antenna design is more pronounced for the receiver systems, where both the collected power by the antenna and its FOV often need to be maximized. While some novel solutions have been demonstrated recently, identifying fundamental limits and trade-offs in nano-photonic antenna design is essential for devising compact antenna structures with improved performance. In this paper, the fundamental electromagnetic limits, as well as fabrication imposed constraints on improving antenna effective aperture and FOV are studied, and approximated performance upper limits are derived and quantified. By deviating from the conventional assumptions leading to these limits, high-performance multi-mode antenna structures with performance characteristics beyond the conventional perceived limits are demonstrated. Finally, the application of a pillar multi-mode antenna in a dense array is discussed, an antenna array with more than 95% collection efficiency and 170∘ FOV is demonstrated, and a coherent receiving system utilizing such an aperture is presented