User's Manual

LILY-W1 series - Data Sheet
UBX-15000203 - R04 Early Production Information Interfaces
Page 10 of 38
2.2 Antenna interfaces
The LILY-W1 series supports either an internal antenna (LILY-W132) or external antennas connected through an
antenna pin (LILY-W131).
2.2.1 Internal antenna
The LILY-W132 has an internal (embedded) 2.4 GHz PIFA antenna. The internal antenna is a PIFA antenna
specifically designed and optimized for the LILY form factor.
Keep a minimum clearance of 5 mm between the antenna and the casing. Keep a minimum 10 mm free space
from metal around the antenna including the area below. If a metal enclosure is required, use LILY-W131 and an
external antenna.
It is recommended to place the LILY-W132 module so that the internal antenna is in the corner of the host PCB
(the corner closest to Pin 11 should be in the corner). The antenna side (short side closest to the antenna),
positioned along one side of the host PCB ground plane is the second best option. It is beneficial to have a large
solid ground plane on the host PCB and have a good grounding on the LILY-W132 module. Minimum ground
plane size is 24x30 mm but recommended is more than 50x50 mm.
The LILY-W132 module has an integrated LTE BAW band pass filter for optimal LTE and Wi-Fi coexistence
applications.
The ANT signal is not available on the solder pins of the LILY-W132 module and no antenna diversity
functionality is available.
2.2.2 External RF antenna interface
The LILY-W131 module has an antenna signal (ANT) pin with a characteristic impedance of 50 Ω for using an
external antenna. The antenna signal supports both Tx and Rx.
The external antenna, for example, can be an SMD antenna (or PCB integrated antenna) on the host board. An
antenna connector for using an external antenna via a coaxial cable could also be implemented. A cable antenna
might be necessary to use if the module is mounted in a shielded enclosure such as a metal box or cabinet.
An external antenna connector (U.FL. connector) reference design (see LILY-W131 Antenna Connector -
Reference Design [5]) are available and must be followed to comply with the LILY-W1 FCC/IC modular approvals.
Also see and the list of approved antennas (section 7.2).
The LILY-W131 module also supports an antenna diversity solution with an external antenna switch (see Figure
2). The switch is controlled by the ANT_SEL and the inverse ANT_SEL-n control signals are controlled from
LILY-W131. See LILY-W1 series System Integration Manual [2] for more information about antenna switch
design.
Figure 2: LILY-W131 antenna diversity solution with an external antenna switch controlled by LILY-W131
The LILY-W131 can be used in coexistence with a LTE modem. An external additional LTE band pass filter may be
required depending on the location of the antennas. Refer to LILY-W1 series System Integration Manual [2] for a
list of suitable LTE filters.
The FCC/IC modular approvals are not including an additional LTE filter or an antenna switch design.