APPLICATION NOTES
The ZAMP002 is a wideband RFIC amplifier designed
for use primarily in DBS applications. The amplifier is
designed to provide a 50 Ohm input and 75 Ohm output
and thus requires no additional matching components.
The input and output signal connections each require a
DC blocking capacitor (C1 and C2). A suitable value for
these capacitors is 100pF for the 950MHz to 2150MHz
frequency range. For other frequency ranges the value
of the capacitor should be such that its reactance at the
lowest operating frequency is small when compared to
50 ohms (or 75 Ohms for the output). Supply
de-coupling is also recommended and should take the
form of a suitable 100pF capacitor, C3, for the 950MHz
to 2150MHz frequency range. The 100pF capacitor
should be mounted as close to the Vcc pin of the
amplifier as is physically possible. An additional low
frequency de-coupling capacitor, C4, with a value of
100nF is also advised. The ZAMP002 requires a RF
choke inductor, L1, providing DC bias to the output
line. A value of 100nH is recommended for the 950 MHz
to 2150MHz frequency range.
An example layout for a test board for the ZAMP series
can be seen above. This was designed for an FR4 board
1 x 1 inch, 0.016 inch thick with a copper thickness of 35
microns. Edge mounted SMA connectors were used
for the RF signals.
ZAMP002
SEMICONDUCTORS
ISSUE 2 - MARCH 2003
6
TEST CIRCUIT LAYOUT