Large-scale W-band focal plane array developments for passive millimeter-wave imaging

A state-of-the-art W-Band passive millimeter wave focal plane array (FPA) consisting of 1040 highly integrated direct detection pixel has been designed, developed, assembled and tested. The FPA has been integrated into a passive millimeter wave video camera and has generated real time images. Each pixel is a highly integrated MMIC chip receiver. The MMIC chip is a wide band, high gain, low noise, 0.1 micrometer InGaAs HEMT amplifier with an integrated switch and Schottky barrier diode detector. The FPA uses a brick architecture. Each brick or module consists of 4 MMIC chips or pixels and lay side-by- side on the card. Many cards are stacked to create the array of pixels. In the next generation FPA, the 1 X 4 modules and cards have been dramatically simplified with 50% less assembly time. In addition, the module and card still require no tuning and minimal test time. Thus a significant cost reduction in the FPA is expected over the first generation FPA without sacrificing performance. To further reduce cost and improve performance, new MMIC chips are being designed.