Agilent Technologies E7402A, E7405A, E7404A, E7403A Third-Order Intermodulation Equipment Setup

Making Basic Measurements

Identifying Distortion Products

Figure 1-38 Third-Order Intermodulation Equipment Setup

NOTE	The combiner should have a high degree of isolation between the two
	input ports so the sources do not intermodulate.
	2.	Set one source (signal generator) to 300 MHz and the other source to
		301 MHz, for a frequency separation of 1 MHz. Set the sources equal
		in amplitude as measured by the analyzer (in this example, they are
		set to − 5 dBm).
	3.	On the analyzer, perform a factory preset by pressing Preset,
		Factory Preset (if present).
	4.	Set the Y-Axis Units to dBm by pressing AMPLITUDE, More,
		Y-Axis Units, dBm.
	5.	Set the resolution bandwidth to spectrum analyzer coupling by
		pressing BW/Avg, Res BW (SA).
	6.	Set the span to 5 MHz by pressing SPAN, Span, 5, MHz. This is wide
		enough to include the distortion products on the screen.
	7.	Tune both test signals onto the screen by setting the center
		frequency 300.5 MHz, press FREQUENCY, Center Freq, 300.5, MHz.
		If necessary, use the front-panel knob to center the two test signals
		on the display.
	8.	To be sure the distortion products are resolved, reduce the resolution
		bandwidth until the distortion products are visible by pressing
		BW/Avg, Res BW, and then use the step-down key (↓ ) to reduce the
		resolution bandwidth until the distortion products are visible.
	9.	For best dynamic range, set the maximum mixer input level to
		− 30 dBm and move the signal to the reference level: press

AMPLITUDE, More, Max Mixer Lvl, –30,dBm.

46 Chapter 1