NXP Semiconductors FREESCALE MC13192, Reference Manual, Page: 27 / 34

RF Front End
MC13192EVB Reference Manual, Rev. 1.2
Freescale Semiconductor 3-9
3.8.2 Output Filter
L103 and C112 can be left out in many applications, but spurious performance should be tested. If the
antenna does not have a DC connection to ground, C104 can be left out.
3.8.3 Switch
In the case of a dual antenna approach, C103, C104, and the switch can be left out. However, when using
chip antennas, it is often less expensive to use the switch and one antenna.
3.8.4 TX Match
L102 can be left out which results in a power loss of approximately 2dB. However, if the layout is
optimized for low capacitance, the power loss may even be less. C130 can usually be replaced with a 100
nF capacitor without any performance loss. Then C106 can be left out because C130 will provide adequate
decoupling.
Z102 can be replaced by a discrete balun, but a discrete balun is sensitive to load impedance and PCB
spread, and it takes up more board space than the ceramic types. As the total cost is often the same (or even
more) than the ceramic balun, it is not recommended to use a discrete balun.
3.8.5 RX Match
R109 can be left out in most cases which results in better sensitivity. L101 can be left out, but it will result
in a 4.5-5 dB sensitivity loss. A PCB hairpin can replace L101. C102 can be left out with little performance
loss in many applications. Z101 is the same as in the TX chain.
Refer to AN2731 for more information on balanced antenna designs which interface directly to the
MC13192.
3.8.6 Built in Antenna
The built in F-antenna is a simple PCB antenna which provides good performance at low cost. It is also
reasonably small in size. The antenna exhibits adequate broadband matching and good efficiency. The
radiation pattern is relatively omni-directional.