spur_track_with_if()

Returns the maximum power of all signals appearing in a user-specifiable IF band, as a single RF input signal is stepped. In addition, it shows the IF frequencies and power levels of each signal that appears in the IF band, as well as the corresponding RF signal frequency

Syntax
IFspur = spur_track_with_if(vs(vout, freq), if_low, if_high, rout)

Arguments

Name	Description	Range	Type	Required
vout	IF output node name		string	yes
if_low	lowest frequency in the IF band	[0, ∞)	real	yes
if_high	highest frequency in the IF band	[0, ∞)	real	yes
rout	load resistance connected to the IF port, necessary for computing power delivered to the load	[0, ∞)	real	yes

Examples

IFspur=spur_track_with_if(vs(HB.VIF1, freq), Fiflow[0, 0], Fifhigh[0, 0], 50)
where
VIF1 is the named node at the IF output.
Fiflow is the lowest frequency in the IF band.
Fifhigh is the highest frequency in the IF band.
50 is the IF load resistance.
Fiflow and Fifhigh are passed parameters from the schematic page (although they can be defined on the data display page instead.) These parameters, although single-valued on the schematic, become matrices when passed to the dataset, where each element of the matrix has the same value. The [0, 0] syntax just selects one element from the matrix.

Defined in

$HPEESOF_DIR/expressions/ael/digital_wireless_fun.ael

See Also

spur_track()

Notes/Equations

Used in Receiver spurious response simulations.

IFspur computed above will be the power in dBm of the maximum signal appearing in the IF band, versus RF input frequency. Note that it would be easy to modify the function to compute dBV instead of dBm.

This function is meant to aid in testing the response of a receiver to RF signals at various frequencies. This function, similar to the spur_track function, shows the maximum power of all signals appearing in a user-specifiable IF band, as a single RF input signal is stepped. In addition, it shows the IF frequencies and power levels of each signal that appears in the IF band, as well as the corresponding RF signal frequency. There could be fixed, interfering tones present at the RF input also, if desired. The maximum IF signal power may be plotted or listed versus the stepped RF input signal frequency.