ML7404 Family LSIs
Hardware Design Manual
FEXL7404DG-03
11
Thick line is Zo=50 ohm
ANTENNA
PA_OUT(#20)
LNA_P(#24)
REG_PA(#21)
Inductor
(L3)
LPF, suppress harmonics
5. RF matching component values
Table 5.1 shows the measured impedance of the PA_OUT (#20) pin and the LNA_P (#24) pin at operationg
frequency.These impedances are presented as a reference.
Table 5.1 Measured RF impedance
R + jX [Ω]
Tx
（
PA_OUT(#20) pin
）
Rx
（
LNA_P(#24) pin
）
Target
Measurement
frequency
13dBm
10dBm
0dBm
ML7404
426MHz
6.5 + j9.8
4.9 + j10.1
2.0 + j11.0
11.5 - j204.3
868MHz
43.6 - j7.6
63.2 - j3.4
204.3 + j92.1
10.2 - j132.2
920MHz
48.2 - j8.8
73.0 – j14.1
259.3 – j130.3
10.6 - j130.3
[Note] These component values appropriate for use on the LAPIS Semiconductor’s RF board. It is not
guaranteed to obtain same result on your specific board.
5.1. ANTENNA Tx and Rx direct tie matching circuit
Figure 5.1.1 shows the Antenna maching circuit configuraltions. The REG_PA (#21) pin provides the DC bias to
the PA_OUT(#20) pin. This DC bias should be provided through the inductor (L3). Chebyshev lowpass filter is
consist of components L5~L8 and LPF1, C47~C50,to suppress harmonics.
Figure 5.1.1 Transmission matching circuit configurations
