Akiko Kohmura

76.5 GHz millimeter-wave radar for foreign objects debris detection on airport runways

The paper is a joint work between the LEAT (France) and the ENRI (Japan) in the framework of a Sakura project supported by the JSPS and the French Ministry of Foreign Affairs. The purpose is the study of a FOD (Foreign Object Debris) detection system on airport runways. A FM-CW mm-Wave radar working between 76.25 and 76.75 GHz is used together with a high directivity printed reflectarray. Measurement results show detection capabilities of a -20 tlBsm cylinder up to 35 m which is 10 m less than the FAA recommendations. Antenna improvements are discussed for reaching the requirements and system performance as well as the use of calibration objects.

Design and Field Feasibility Evaluation of Distributed-Type 96 GHz FMCW Millimeter-Wave Radar Based on Radio-Over-Fiber and Optical Frequency Multiplier

Foreign object debris (FOD) on airport runways must be removed immediately. To detect small debris, we proposed and developed an optically-connected distributed-type 96 GHz millimeter-wave radar system based on radio-over-fiber (RoF) technology and an optical fiber network. The proposed distributed-type radar system offers both improved FOD detection characteristics and cost performance. This paper details the design and field feasibility evaluation of the 96 GHz frequency-modulated continuous wave radar system that uses RoF and an optical frequency multiplier. Firstly, the problem of long distance RoF transmission, which limits the practical use of the RoF networked radar system in the airport environment, is discussed. Secondly, the concept and architecture of the millimeter-wave radar system are discussed and demonstrated focusing on its use in actual airports. Then, the results of a field experiment are shown to confirm the feasibility of the radar system. Finally, the effectiveness of the high-speed signal processing and generation circuits inside the central unit is evaluated at an actual airport based on the results of non-coherent and coherent signal integration.

Microwave shielding and polarization characteristics of carbon fiber reinforced plastic laminates with unidirectional materials

The electromagnetic shielding and polarization characteristics of carbon fiber reinforce plastics (CFRP) based on unidirectional (UD) materials are determined by experiments. The UD CFRP laminates have single direction carbon fibers, which behave the same as wire-grid structures. The measured transmission coefficient for the 1 ply UD CFRP laminate is about -2dB, when the direction of the carbon fiber is perpendicular to the incident wave. The polarization ratio is more than 20dB for most frequency points. In addition, it is confirmed that the transmission coefficient can be controlled by rotating the UD CFRP laminates.

Design and construction methodology of 96 GHz FMCW millimeter-wave radar based on radio-over-fiber and optical frequency doubler

To detect small debris on the airport surface, the optically-connected distributed-type 96 GHz millimeter-wave radar system, which is based on radio-over-fiber (RoF) technology and an optical fiber network, has been proposed and developed. Such foreign object debris (FOD) is required to be removed immediately. The distributed-type radar system enables the improvement of both the FOD detection and cost performance. In this paper, design and construction methodology of the 96 GHz frequency-modulated continuous wave radar system based on the RoF and optical frequency doubler is discussed. The architecture of the millimeter-wave radar system, which is designed to enable a long distance RoF transmission, is demonstrated. In addition, the effectiveness of the high-speed signal processing circuit inside the central unit is evaluated at an actual airport.

Experimental feasibility study of 96 GHz FMCW millimeter-wave radar based upon radio-over-fiber technology-fundamental radar reflector detection test on the Sendai airport surface-

Based on radio-over-fiber (RoF) technology, we have proposed a novel architecture foreign object debris (FOD) detection system. The FODs on the airport surface may cause damage to aircraft and must be immediately removed. The optically-connected millimeter-wave radar with separated front-ends enables both low-cost and high-detection performance. In this paper, the feasibility and effectiveness of the 96 GHz optically-connected millimeter-wave radar is experimentally confirmed through the target detection test on the airport surface. The distributed millimeter-wave radar system, which is connected by the RoF converter, is fabricated. In addition, the radar reflectors, which are located on the apron of the Sendai airport, are successfully detected by the radar system.

Evaluation of microwave shielding characteristics of quasi-isotropic carbon fiber reinforced plastic laminates based on unidirectional materials

The microwave shielding characteristics of quasi-isotropic carbon fiber reinforced plastics (CFRP) based on unidirectional (UD) materials are experimentally evaluated. First, fundamental characteristics of a UD CFRP laminate and a quasi-isotropic CFRP laminate are discussed. Second, shielding and polarization characteristics of a simple UD CFRP laminate are measured between 400 MHz and 6 GHz. The UD CFRP laminate, which has a same fiber direction, operates as a wire-grid and has more than 30 dB polarization ratio. Then, the dielectric constants of the fabricated CFRP laminate are measured by using the impedance analyzer. However, it was not suitable to describe whole wire-grid characteristics of the UD CFRP laminates. Finally, the measurement result of the quasi-isotropic CFRP laminate shows more than 40 dB shielding characteristics, which is almost the same as the dynamic range of the measurement system.

Basic characteristic evaluation of aeromacs prototype system in send AI airport

A new aeronautical airport communication system called Aeronautical Mobile Airport Communications System (AeroMACS) is under standardizing. This paper reports performance evaluation of an AeroMACS prototype system on airport environment. First, we show that RSSI is the most important factor for airport condition. Second, we estimate coverage of the system. Finally, we compared the results of field test with those of laboratory test.

W-band phase measurement of reflected wave from diode grid for reflectarrays

Foreign Objects and Debris (FODs) must be removed from runways. Under the necessity of automatic continuous survey, we are investigating a new FOD detection system based on MilliMeter Wave (MMW) radar system connected by Radio-over-Fiber (RoF) lines. This RoF radar project is also interested in beam steering antennas such as phased array antennas. This paper describes a concept of a diode grid reflector antenna. We also introduce a phase evaluation system to measure the phase of reflected wave from the circuit boards in W band. The validity of the system is confirmed to compare between simulation and measurement. Moreover, we measured diode test boards to change the phase of reflected wave. As a result, we find that it is possible to change the reflection phase using switching diodes.

Painted styrene radome for foreign objects and debris detection radar in W-band

In this paper a new radome structure made from styrene foam coated with Efrethan® is described together with experiments on its performance. Sufficient strength to endure environmental stress is obtained from the Efrethan layer. Optimal losses are obtained from 1mm or 2mm coating at three frequencies in W-band. The developed radome performed with − .18 dB loss at 76 GHz without any disturbance of antenna pattern.

Design and measurement of W-band offset stepped parabolic reflector antennas for airport surface foreign object debris detection radar systems

Debris on the airport surface may cause severe damage to aircraft. To detect these obstacles, foreign object debris (FOD) detection systems have been developed recently. By utilizing high-sensibility and weather robustness characteristics, the millimeter-wave radar is an essential sensor device for these systems. This paper discusses an offset parabolic reflector antenna for airport surface FOD detection radar systems. Firstly, the overview of the FOD detection radar systems, which employs a band of between 92 GHz and 100 GHz, is shown. For the azimuth beam scanning antenna, the antenna is required to achieve both a narrow azimuth beamwidth and a wide elevation beamwidth. Secondly, the stepped parabolic reflector is newly designed to obtain an 8 degree elevation -20 dB down power beamwidth. Finally, the designed reflector is fabricated based on chemical wood materials. The measured result shows the 38 dBi gain and the 8.4 degree beamwidth for the elevation plane.