LISA-U series - System Integration Manual
UBX-13001118 - R17
Advance information
Design-In
Page 143 of 190
Figure 77 shows an example of this measurement:
Figure 77: |S
11
| sample measurement of a penta-band antenna that covers in a small form factor the 4 GSM bands (850 MHz, 900
MHz, 1800 MHz and 1900 MHz) and the UMTS Band I
Figure 78 shows comparable measurements performed on a wideband antenna. The termination is better, but
the size of the antenna is considerably larger.
Figure 78: |S
11
| sample measurement of a wideband antenna
2.4.2
Antenna radiation
An indication of the antenna’s radiated power can be approximated by measuring the |S
21
| from a target antenna
to the measurement antenna, using a network analyzer with a wideband antenna. Measurements should be
done at a fixed distance and orientation, and results compared to measurements performed on a known good
antenna. Figure 79 through Figure 80 show measurement results. A wideband log periodic-like antenna was
used, and the comparison was done with a half lambda dipole tuned at 900 MHz frequency. The measurements
show both the |S
11
| and |S
21
| for the penta-band internal antenna and for the wideband antenna.
Figure 79: |S
11
| and |S
21
| comparison between a 900 MHz tuned half wavelength dipole (green/purple) and a penta-band internal
antenna (yellow/cyan)
