An ultrasound beam travels through a three-layer medium: Me…

An ultrasound beam travels through a three-layer medium: Medium A, Speed = 1540 m/s Medium B, Speed = 2310 m/s Medium C, Speed = 1540 m/s. All interfaces in this layered medium run parallel to one another. The angle of incidence of the ultrasound at the interface between medium A and medium B is 30° from the interface normal. What angle will the ultrasound beam propagate in medium C?

An ultrasound beam with a frequency of 5 MHz passes through…

An ultrasound beam with a frequency of 5 MHz passes through three different tissues with the following characteristics: Tissue A: 2 cm thick with attenuation coefficient 0.5 dB/cm @ 5MHz Tissue B: 3 cm thick with attenuation coefficient 0.7 dB/cm @ 5MHz Tissue C: 1 cm thick with attenuation coefficient 1.2 dB/cm @ 5MHz If the initial intensity of the ultrasound beam is 100 mW/cm², what is the approximate intensity after passing through all three tissues? The reflection at each interface is not considered here.

Orthogonal frequency division multiplexing (OFDM) divides th…

Orthogonal frequency division multiplexing (OFDM) divides the operating spectrum into multiple subcarriers that are used to transmit data in parallel.  By using several subcarriers extended over a larger frequency spectrum, OFDM provides greater immunity from RFI compared to narrow band frequency channels (i.e., narrow band FDM).