Agilent Technologies E1441A Fs = 1 / 9 x 200 ∝s = 555.555 kHz, Points P = C/S / Fs =, y = mX + b

even numbers only (rounded down)

Equations:

Compute the modulation pre-scaler divider:

S =	k	(truncated to integer value ≥ 1)
	--
	F

Compute the number of points for the modulation waveform length:

P =	2 ⋅ C	(rounded down to even number)
	(------------------------1 + S) ⋅ ---F

Waveshapes are automatically expanded or compressed to match length “P” computed above and downloaded into modulation RAM.

Example: Assume that you need to phase-continuously frequency hop between the following nine frequencies every 200 ∝s.

15.0MHz, 1.001 MHz, 9.780 MHz, 12.375 MHz, 0.5695 MHz, 3.579 MHz, 0.8802 MHz, 0.6441 MHz, and 10.230 MHz.

Solution: Create a modulation arbitrary waveform that is precisely sampled in FM modulation.

Fs = 1 / (9 x 200 ∝s) = 555.555 kHz (effective point clock)

Points (P) = (C/S) / Fs = 2250

S=1. If P greater than 4096, divide C by the smallest S to bring P within range. Round down to an even P value.

Modulation Frequency (F) = (C/S) / 2 x 2250 = 555.55555 Hz

Round down in sixth digit to get modulation frequency to set.

Set the modulation frequency to 555.555 Hz.

Set the carrier frequency to (Max F + Min F) / 2 = 7.784750 MHz.

Set deviation (pk) frequency to (Max F – Min F) / 2 = 7.215250 MHz

Create and download a nine-segment arbitrary waveform with the values shown below. Each segment is 250 points long (2250/9) for a total of 2,250 points. Use the DATA VOLATILE command download to achieve 12-bit frequency resolution for each point.

y = mX + b

To Check: Enable FM by sending the following commands:

"FM:STATE ON" "FM:INT:FREQ 555.555" "DIAG:PEEK? 0,0,0"

enter results < Prescale# (S) >,< Points (P) >

162 Agilent E1441A Function Generator Tutorial Appendix C