Receiver Circuit Testing Test setup Eye diagrams BER measurement Eye - BER relationship

Circuit Test Setup Pattern Generator Attenuator Oscilloscope

Signal Monitoring Terminated 50  coax for > 1 Mbps capacitance (NRZ data, 50 ohms): –1/2piRC > data rate

RF Oscillation Prevention Grounded coax for all inputs Single ground point for bias

RF Circuit Test 50  transmission line to chip: –Stripline printed circuit boards –or short lines 50  output drivers

BER Measurement PRBS source Attenuation Error measurement

PRBS source Pseudo random data is severe test of receiver Length of zero or one string is critical (ISI) Eye diagram is “open” for low ISI

Attenuation Sensitivity of receiver: –BER at fixed p in and data rate Noise floor due to dynamic range limits –Need to vary p in

Error Measurement Correlate PRBS and output data BER = number of errors / data bits sent BER = or typical i.e., 1 error per Gbit of data = 10 -9