Wideband Microwave Camera for Real-Time 3-D Imaging

This paper presents a microwave camera design operating in the 20-30 GHz frequency range and capable of producing 3-D images at video frame rate (i.e., real-time), using synthetic aperture radar (SAR) technique. This microwave camera has the potential to provide real-time inspection and diagnosis capabilities in the nondestructive testing, biomedical and security applications, to name a few. The camera utilizes an array composed of a novel array element with built-in dual receivers at its radiating end. The dual receiver design has two significant features particularly important for SAR imaging, namely, it provides for nonuniform spatial sampling, and allows the use of antennas whose sizes are greater than half of the operating wavelength. The camera operates in the monostatic mode where each antenna in the array is used as the transmitting and receiving antenna. A major advantage of this real-time camera design is the simplicity of the microwave circuitry, which reduces the overall size, power consumption, and, cost and renders it portable. The detail design of this wideband microwave 3-D real-time camera is provided along with several images of diverse and complex targets to demonstrate its capabilities and functionality.