Acoustic microscopy acoustic microscope (CSAM), and C-mode scanning acoustic microscope (C-SAM). More recently acoustic microscopes based around picosecond ultrasonics systems have demonstrated acoustic imaging in cells using sub-optical wavelengths working with ultrasonic frequencies into the multi-GHz. Since the vast majority of acoustic microscopes in use today are C-SAM type instruments, this discussion will be limited to these instruments. Ultrasound is broadly defined as any sound having a frequency above 20 kHz, which is approximately the highest frequency that can be detected by the human ear. However, the acoustic microscopes emit ultrasound ranging from 5 MHz to beyond 400 MHz so that micrometre
Cellular frequencies in the US Cellular frequencies in the US The usage of frequencies within the United States is regulated by the Federal Communications Commission (FCC). When distributing initial spectrum licenses in a band the FCC divides the US geographically into a number of areas. A mobile operator (or other interested party) must bid on each area individually. A license owner can use any technology within the licensed area and frequency range subject only to the band rules defining various analog limits. A license owner can also partition the license (split geographically) or disaggregate it (split the whole licensed frequency range into two sub-ranges). Whole,