MAX-M5Q - Hardware Integration Manual
FTX-HW-13008
Objective Specification
Design
Page 24 of 40
4.2.4
Design with GLONASS / GPS passive antenna
In general, GPS patch antennas only receive GPS signals well. A typical return plot (S11 measurement) shows
that the GLONASS signal is highly attenuated. (See Figure 18
u-blox 7 modules supporting GLONASS have a GPS & GLONASS SAW filter (see Figure 17) that lets both GPS
and GLONASS signals pass. For best performance with passive antenna designs, use an external LNA. (See
section 4.2.1.2).
Figure 18: 25*25*4 mm GPS patch antenna on 70*70 mm GND plane
To receive GPS and GLONASS, a special antenna patch (which can receive both GPS and GLONASS) is needed.
The return plot (S11 measurement) in Figure 19 below shows the two areas of lower attenuation.
Figure 19: 25*25*4 mm GPS / GLONASS patch antenna on 70*70 mm GND plane
