Table of Contents
Advertisement
T A K I N G
M E A S U R E M E N T S
START button was first pressed. It may be reset to 0 dBc by checking or un-
checking the Synchronous Level Detector box.
o Averaged is the average of the last ten relative power readings
AM Modulation readings are taken on the AM modulation envelope after IF and
⇒
audio filtering. The units for all AM readings are percent.
3.8 EMC Measurements
You may import CSV files for path loss (e.g. cable loss) and antenna factor, under
File Import. These files should have frequency in MHz, followed by amplitude in
dBc or dB/m. A sample Isotropic Antenna Factor file is included.
To make an EMC measurement, import your Antenna Factor (AF) table. Then click
Reference Level, and select the units you wish to use. Units such as mV/m and
2
nW/cm
, in log and linear scales, are available. If you have any difficulty using these
tools, please contact us.
3.9 Limitations of the Signal Hound
3.9.1
RBW Limitations
Although a resolution bandwidth (RBW) of 0.1 Hz is available for very narrow spans,
be aware of the limitations. The internal timebase has phase noise, limiting the
usefulness of narrow RBWs. For best results, keep your RBW in Hz larger than your
CENTER FREQ in GHz when using the internal timebase. For example, for a 1.6
GHz CF, use an RBW of 1.6 Hz or higher. Your RBW may be 10x less when using a
high quality external timebase.
The Signal Hound mostly uses digital RBWs in powers of two starting at 0.1 Hz.
3.9.2
IF Feed-Through
Intermediate frequencies of 2.9 MHz and 10.7 MHz are used for all frequencies. An
RF input signal near these frequencies may generate spurious responses and degrade
the performance of the image rejection algorithm.
3.9.3
LO Leakage
A Local Oscillator signal may be observed at the RF input port, often found 10.7 MHz
above the RF frequency being scanned. Typically, this level will not interfere with your
measurements. If you are connecting to an antenna, please use the preamplifier and set
the attenuator to 15 dB to minimize LO leakage. This will typically reduce your LO
leakage to less than 2 nanowatts for all frequencies below 1 GHz.
3.9.4
Sweep Time
Sweep Time varies based on system settings. For sweeps with a small span (typically
less than 5 MHz), the user may select slow, medium, or fast sweep speeds, depending
22
Advertisement
Table of Contents
