Noise immunity evaluation of information and communication equipment

The correlation between noise level and transmission speed are verified.

Application

In this paper, the evaluation of a mobile phone module is mentioned as an example.

This system intends to evaluate how the EUT (mobile phone module) put in anechoic box is affected after the signal output from signal generator (SG) is radiated in it. This system has the frequency range from 800MHz to 2.5GHz and is a tool for detecting the EMC problem in the early stage of design or measuring a communication effective throughput by the program of EUT or control equipment.

Solution

System configuration example

Transmission section (1)(2)
Evaluation stage
Measurement & display section

System specification example

Transmission section *Insert an isolator if necessary.

The signal to be applied to EUT is generated. The power is roughly +30 dBm but depending on the measurement band. Transmission section (1) and (2) are installed in one case.

Signal generator	Frequency range	9kHz to 3GHz(CW)
	Output level	-127 to ＋13dBm
Power amplifier	Frequency range	800MHz to 2.5GHz
	Output power	5W以上
LPF*	Cutoff frequency is 1GHz at the measurement from 800MHz to 1GHz, and 2GHz at the measurement from 1.5GHz to 2GHz.
HPF*	Cutoff frequency is 1.6GHz at the measurement from 800MHz to 1GHz, and 3GHz at the measurement from 1.5GHz to 2GHz.
DC block	Parts for cutting DC

Evaluation stage

The signal generated at ① is radiated in anechoic box through an antenna coupler.

Anechoic box	Shielding effectiveness	800MHz to 3GHz(more than 50dB)
	Outside dimensions	approx. 260(W) x 260(H) x 360(D)mm
	Inside dimensions	approx. 200(W) x 100(H) x 300(D)mm
	Table for put EUT	200(W) x 280(D)mm
	I/F	SMA connector *2pcs
Antenna coupler	Frequency range	800MHz to 2.5GHz
	VSWR	2.5以下(800MHz to 2.2GHz)
	Maximum output level	＋38dBm

Measurement & display section

The report will be drawn up after measured in the circumstance of ②.

Spectrum Analyzer	Frequency range	50kHz to 8.5GHz
PC software	The result obtained by spectrum analyzer is displayed and the report is drawn up.
PC	The communication status such as the effective throughput is made sure using the program of control equipment and EUT.