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 suburban areas. Detailed lists: Other articles: 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