Characteristics of Focusing Behavior of Virtual Lens with Variable Diameter

The virtual confocal microscope method is used in microwave imaging to examine the biological tissues. The method depends on focusing the incoming scattered waves from a body to form an image using a virtual lens. A mathematical relationship is found that gives only the possible allowed values for the diameter of the lens for each specific wavelength, minimum required resolution and distance from lens to image. Each of the values of the diameters when used produces images with best quality. Here, we continue on previous work to study the characteristics of the efficiency of the lens in producing images as two parameters are varied. One parameter is the diameter of the virtual lens. Another parameter is the minimum resolution which is required for the calculated images. The efficiency obeys a harmonic behavior as the diameter of the virtual lens changes. Moreover for a constant wavelength, as the minimum required resolution decreases the allowed diameters for the virtual lens to obtain images with good quality become wider. Keywords— Harmonic Frequency; Virtual Confocal Microscope; Image Intensity; Resolution; Saturation Curve