CVBS stands for Composite Video Broadcast Signal, also known as Composite Video Blanking and Sync. Commonly referred to as baseband video or RCA video, it is a traditional image data transmission scheme defined by the National Television System Committee (NTSC) that transmits visual data via analog waveforms.Composite video integrates chrominance (hue and saturation) and luminance (brightness) information, embeds them into blanking pulses, and delivers all data through a single signal line.

It is the format for analog television video signals before being combined with audio signals and modulated onto an RF carrier. For fast-scan NTSC television systems, composite video is amplitude-modulated onto VHF (Very High Frequency) or UHF (Ultra High Frequency) carriers, generating a signal with an approximate bandwidth of 6 MHz.Closed-circuit television systems often adopt coaxial cables for short-distance composite video transmission. Meanwhile, DVD players and video cassette recorders (VCRs) are equipped with composite video input and output ports via phono jacks, also named RCA connectors.

Interference between chrominance and luminance signals is inevitable within composite video, especially under weak signal conditions. This explains why long-distance NTSC TV reception via traditional whip antennas, "rabbit-ear" indoor antennas or outdoor aerials often suffers from false colors or color flickering.CVBS represents an older video transmission standard, specifically the 1st generation video output interface:1st Gen: CVBS2nd Gen: S-VIDEO3rd Gen: VGA4th Gen: DVI5th Gen: HDMI

In modern system integration projects, long-distance transmission of VGA signals poses a prevalent technical challenge. A transmission system covers all links between a computer signal output and display input, including distributors, matrix switches, cables, graphic controllers and related accessories.Over extended transmission distances, system parameters and surrounding electromagnetic interference will noticeably degrade signal integrity, resulting in common abnormalities such as blurry/darkened images, video trailing, ghosting, flickering screens or intermittent blackouts. These faults stem from distinct root causes and require targeted solutions, categorized into four types as follows: