Paul Shu Chung Lee

W-band MMIC direct detection receiver for passive imaging system

W-band MMIC (monolithic microwave integrated circuit) direct-detection receivers for passive millimeter-wave imaging applications have been demonstrated. These receivers were developed using InGaAs HEMT (high electron mobility transistor)-based W-based LNA (low-noise amplifier) and preamplified detector MMICs. The first receiver uses a 50-dB-gain, 6-dB-noise-figure amplifier and a Schottky-barrier-diode waveguide detector. The amplifier uses four W-band MMIC LNAs. The second receiver consists of two three-stage MMIC LNAs and an MMIC preamplified detector chip. Individual receivers were integrated with a millimeter-wave camera system. Field imaging acquisition runs were performed using the camera in stepping pushbroom image acquisition mode, and excellent results were obtained.<<ETX>>

Large scale W-band focal plane array for passive radiometric imaging

This paper discusses the development of a large scale W-band focal plane array (FPA) for passive radiometric imaging application. The goal is to develop a 40/spl times/26 (1040-pixels) FPA to cover 15/spl deg//spl times/10/spl deg/ instantaneous field-of-view. Each receiver consists of a single direct detection MMIC which is a W-band high gain, wide bandwidth switched LNA with integrated Schottky barrier diode detector. A 1/spl times/4 FPA module, employing linearly tapered slot antenna, is used as the basic building block for the FPA. Typical receiver temperature sensitivity is 0.4 K with 10 ms integration time. For the first time, an automated assembly process is used to produce W-band MMIC modules in large volume.

Millimeter-wave imaging using preamplified diode detector

A 2-pixel imaging array was developed to demonstrate millimeter-wave imaging. Each pixel consists of a Q-band Vivaldi antenna and a preamplified diode detector, using InGaAs pseudomorphic HEMT MMIC low-noise amplifiers (LNAs) and a beam-lead Schottky-diode detector. The approach does not require local oscillator (LO) power, is compatible with MMIC technology, and can reduce the complexity and manufacturing cost of millimeter-wave imaging arrays. The preamplified diode detector exhibited 17-V/ mu W responsivity at 44 GHz and -75-dBm tangential sensitivity at 1-MHz video bandwidth. The array demonstrated millimeter-wave imaging of three vehicles in a parking lot. >

A passive millimeter wave camera for aircraft landing in low visibility conditions

Fog and low visibility conditions have hampered aviation since its inception. Fog-related accidents are numerous, and canceled take-offs and landings due to fog and low visibility conditions (Cat III) have significant economic impact on airlines, parcel carriers and general aviation. Millimeter waves have good propagation properties in weather and give adequate spatial resolution when used to image the forward scene. Passive millimeter wave focal plane array cameras are new sensors which, integrated into future guidance and landing systems, promise to be an effective aid, or alternative, to existing technology for aircraft landings and take-offs under Cat III conditions. They can produce visual-like radiometric images at real time frame rates (up to 30 Hz), and are directly amenable to image fusion with infrared and visible images. TRW has been actively involved in developing and productizing this technology both at the hardware and the system levels. >

A passive millimeter wave camera for landing in low visibility conditions

Fog and low visibility conditions have hampered aviation since its inception. Fog-related accidents are numerous, and canceled take-offs and landings due to fog and low visibility conditions (Cat III) have significant economic impact on airlines, parcel carriers and general aviation. Millimeter waves have good propagation properties in weather and give adequate spatial resolution when used to image the forward scene. Passive millimeter wave focal plane array cameras are new sensors which, integrated into future guidance and landing systems, promise to be an effective aid, or alternative, to existing technology for aircraft landings and take-offs under Cat III conditions. They can produce visual-like radiometric images at real time frame rates (30 Hz), which can be directly fused with infrared and visible images. TRW has been actively involved in developing and manufacturing this technology both at the hardware and the system levels.<<ETX>>

A passive millimeter wave camera for landing under low visibility conditions

Passive millimeter wave (PMMW) focal plane array cameras are new sensors capable of imaging the forward scene under fog and low-visibility conditions at video frame rates. PMMW imaging sensors measure the blackbody radiation naturally emitted from the imaged scene. These cameras promise to be an effective aid, or an alternative, to existing technology for aircraft landing and surface operations under Category Ill weather conditions. The impact of this technology on air traffic can be significant in terms of reducing weather-related accidents and delays as well as affecting the economics of airlines, parcel carriers and general aviation. The authors discuss the system engineering necessary to validate the missions operational requirements. The associated hardware development work is outlined. The suitability of PMMW cameras to future enhanced and synthetic vision systems is considered.<<ETX>>

183 GHz InP MMIC Based Radiometer

This paper describes the design and development of a state-of-the-art dual-channel 183 GHz InP based Monolithic Microwave Integrated Circuit (MMIC) radiometer. This is the worlds first reported monolithic radiometer that operates at 183 GHz enabling high precision micro-miniature sensing of atmospheric chemistry components in this band. The radiometer features the following key components: a plug-in front end low noise amplifier module utilizing a broadband InP MMIC that sets the system noise figure, a low loss waveguide diplexer module, waveguide-to-microstrip transitions fabricated on Z-cut quartz, a mechanical design that can be easily modified to be hermetic, dual-channel output allowing double sideband detection, and a combination of HEMT and HBT InP and GaAs MMIC active components.

Passive Millimeter Wave Camera for Vehicle Guidance in Low Visibility Conditions

Passive millimeter wave (PMMW) imaging sensor technology has made significant advances in recent years to permit the development of manufacturable cameras which can be economically produced. In addition to its operation in adverse weather, the PMMW camera is non-emitting which makes it suitable for both military and civilian applications. For example, aircraft executing autonomous landing using GPS, need an all weather, real time, true image of the forward scene during the touch-down, roll-out, turn-off and taxi maneuvers. The PMMW camera not only provides such an image, but is easily implementable as a sensor for the pilot, and as a system which operates in an airport environment. We shall address these issues and discuss other applications of this new sensor technology.