Figure 4

SEM image of the fabricated device prototype. (a) The detector and bias lines are at the center of this image, and connected to four large bias pads, which were wirebonded and connected to DC bias source during the measurement. (b) Bias pads are connected to bias lines. The length of each bias lines with its inline filter is 50 μm. (c) The magnified image of the two Yagi-Uda arrays and part of the bias lines with short stub filters is shown in the inset. The whole antenna part is fabricated in a single lithography step, while the bias lines are formed using a separate step.