Measures the magnitude of an input signal versus frequency
Keywords
analyzer, electrical, unidirectional, bidirectional
Ports
| Name | Type |
|---|---|
| input | Electrical Signal |
Properties
General Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
name Defines the name of the element. |
Spectrum Analyzer | - | - |
|
annotate Defines whether or not to display annotations on the schematic editor. |
true | - | [true, false] |
|
enabled Defines whether or not the element is enabled. |
true | - | [true, false] |
|
type Defines the element unique type (read only). |
Spectrum Analyzer | - | - |
|
description A brief description of the elements functionality. |
Measures the magnitude of an input signal versus frequency | - | - |
|
prefix Defines the element name prefix. |
RFSA | - | - |
|
model Defines the element model name. |
- | - | - |
|
library Defines the element location or source in the library (custom or design kit). |
- | - | - |
|
local path Defines the local path or working folder $LOCAL for the element. |
- | - | - |
|
url An optional URL address pointing to the element online help. |
- | - | - |
|
icon type Defines the icon or element symbol view option. |
small | - | [small, medium |
Standard Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
limit frequency range Enables setting the frequency range of the analysis. |
false | - | [true, false] |
|
frequency range The frequency range (bandwidth) of the analysis. |
1 |
THz* *std. unit is Hz |
(0, +∞) |
|
plot format Defines the plot format for the results. |
power | - | [rectangular, power |
|
power unit Defines the power unit to plot the results. |
dBm | - | [W, dBm, W/Hz, dBm/Hz |
|
reference level Defines the analyzer reference power level. Intensity plots are set to zero at this point. |
0 |
dBm* *std. unit is W |
(-∞, +∞) |
|
remove dc Defines whether or not to display the DC component. |
false | - | [true, false] |
|
sensitivity The minimum detectable signal power level. |
-100 |
dBm* *std. unit is W |
(-∞, +∞) |
|
resolution Defines the type of filter used to simulate the analyzer resolution bandwidth |
disable | - | [disable, rectangular function, Gaussian function |
|
bandwidth Defines the resolution bandwidth. |
10 |
GHz* *std. unit is Hz |
[0, +∞) |
|
limit time range Enables setting the time range( start/stop) of the analysis. |
false | - | [true, false] |
|
start time Time instant to start the signal analysis. |
0 | s | [0, +∞) |
|
stop time Time instant to stop the signal analysis. |
1 | s | [0, +∞) |
Enhanced Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
spectrogram Defines whether to enable spectrogram plots and allows for a choice between waterfall or average plots. Waterfall spectrogram shows how the spectrum changes over time, while average spectrogram illustrates the mean power as a function of frequency or wavelength. |
disable | - | [disable, waterfall, average |
|
spectrogram window function Defines the spectrogram window function. Window functions mitigate spectral leakage by tapering the time-domain signal at the edges. |
rectangular | - | [rectangular, hamming, hanning, blackman |
|
spectrogram time window Defines the duration of the spectrogram window. Large time window provides higher frequency resolution but may result in lower time resolution. |
%time window%/20 | s | [0, +∞) |
|
spectrogram time overlap Defines the overlap between adjacent time windows. Overlapping windows help reduce artifacts at the edges of each segment. A zero overlap may result in discontinuities at window boundaries. |
%time window%/30 | s | [0, +∞) |
Simulation Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
input signal selection Input signal selection option. |
last | - | [last, index |
|
input signal index The signal index to analyzed. |
1 | - | [1, +∞) |
|
include delays Defines whether inserted delays should be included as part of the signal or not. |
false | - | [true, false] |
Display Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
refresh Defines whether or not to update display and annotations during the simulation. |
true | - | [true, false] |
|
refresh length Defines how ofter to update the element. This is the minimum number of new data values available at the element input port that will trigger the element update. |
1024 | - | [0, +∞) |
|
limit display memory Defines whether or not to limit the number of values displayed in the element display. |
true | - | [true, false] |
|
display memory length This is the number of data values used to update the display and annotations during the simulation. |
2048 | - | [2, +∞) |
Results
| Name | Description |
|---|---|
| signal | The input signal spectrum. |
| spectrogram | The input signal spectrogram. |
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Implementation Details
The spectrum analyzer measures the power spectrum of the input electrical signal versus its frequency. Please see the example file OSC_RFSA.icp for more information. The following figure shows the system in the example file.
In the system, two sinusoidal waves with different amplitudes and frequencies are added together and connected to a spectrum analyzer. The frequencies for the two sinusoidal waves are 10 GHz and 6 GHz, respectively. Hence the output of the spectrum analyzer should have one peak at 6 GHz and another one at 10 GHz.
There are two plot formats of the spectrum analyzer, rectangular and power. The power unit for the power plot can be W, dBm, W/Hz, and dBm/Hz. If W or dBm are selected and the RFSA's resolution is set to disable, the frequency resolution of the spectrum will be used as the bandwidth of the power measurement. Due to the properties of the discrete Fourier transform used to obtain the spectrum, the frequency resolution is equal to the simulation's sample rate divided by the number of samples.
The rectangular plot format plots the amplitude/linear power of the signal versus its frequency in double sidebands, while the power plot format plots the power of the signal in linear and/or dB scale versus its frequency in single sideband. The following figures are the output measured by the spectrum analyzer with different plot formats.
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