This lesson covers the fundamental concepts of CMOS RF integrated circuits, focusing on transmission media and reflections. It explains the importance of characteristic impedance in different transmission mediums such as air, optic fiber, and wires. The lesson also discusses the concept of reflection coefficient and its role in the transmission of waves. It further elaborates on the significance of matching the load impedance with the characteristic impedance to conserve the shape of the waveform and avoid dispersion. The lesson also touches upon the standard characteristic impedance values used in different applications.
00:23 - Introduction
12:12 - Impact of the characteristic impedance of the transmission medium on the reflection coefficient
32:31 - Losses in transmission media
42:50 - Matching the load impedance with the characteristic impedance of the transmission medium
52:03 - Summary
- Every transmission medium, whether it's air, an optic fiber, or a wire, has a characteristic impedance.
- The reflection coefficient, which is the ratio of the wave that gets reflected back to the wave that was incident, plays a crucial role in wave transmission.
- Matching the load impedance with the characteristic impedance of the transmission medium is crucial to conserve the shape of the waveform and avoid dispersion.
- The standard characteristic impedance values used are 50 ohms for most applications and 75 ohms for cable TV and television systems.
- The concept of dispersion occurs when the load resistance is not matched to the characteristic impedance of the wire, leading to an approximation of the transmitted pulse instead of an exact pulse.