Manchester Encoding Bandwidth

Formula

Description

Manchester encoding represents each bit as a transition: a rising edge for one logic level and a falling edge for the other. This guarantees a transition in every bit period, providing embedded clock recovery at the cost of doubling the required bandwidth compared to NRZ encoding. It is used in 10BASE-T Ethernet, RFID, and various industrial protocols where self-clocking is more important than bandwidth efficiency. The minimum bandwidth required is twice the data rate because each bit period contains a full cycle of the clock frequency.

Variables

• BW — Required bandwidth in hertz (Hz)
• bitrate — Data rate in bits per second (bps)

Practical Notes

Manchester encoding is DC-balanced, meaning the average voltage is always at the midpoint, which allows AC coupling of the signal. This is why 10BASE-T Ethernet uses Manchester encoding with transformer coupling. For higher-speed Ethernet (100BASE-TX and above), more bandwidth-efficient encoding schemes like MLT-3 and PAM-5 are used instead.