MAX2406EVKIT View Datasheet(PDF) - Maxim Integrated
Part Name
Description
MFG CO.
'MAX2406EVKIT' PDF : 4 Pages View PDF
MAX2406 Evaluation Kit
Low-Noise Amplifier
1) Set the RXEN jumper (JU1) on the EV kit to the
“logic 1” position. This enables the MAX2406.
2) Connect a DC supply set to 3V (through an amme-
ter, if desired) to the VCC and GND terminals on the
EV kit. Do not turn on the supply.
3) Connect one RF signal generator to the LNAIN SMA
connector. Do not turn on the generator’s output.
Set the generator for an output frequency of 1.9GHz
and a power level of -40dBm.
4) Connect a spectrum analyzer to the LNAOUT SMA
connector on the EV kit. Set the spectrum analyzer
to a center frequency of 1.9GHz, a total span of
200MHz, and a reference level of 0dBm.
5) Turn on the DC supply; the supply current should
read approximately 20mA (if using an ammeter).
6) Activate the RF generator’s output. A 1.9GHz signal
shown on the spectrum analyzer’s display should
indicate a typical gain of 16dB after accounting for
cable losses.
7) If desired, the shutdown feature can be tested by
moving the RXEN jumper (JU1) into the “logic 0”
position. This disables the part and reduces the
supply current to typically 0.1µA.
Receive Downconverter Mixer
1) Remove the RF signal generator and spectrum ana-
lyzer from the LNAIN and LNAOUT connections, if
necessary. The DC supply connections needed for
testing the downconverter mixer are the same as in
the LNA section.
2) Connect one RF signal generator (with the output
disabled) to the LO SMA connector. Set the fre-
quency to 1.5GHz and the output power to -10dBm.
This is the LO signal.
3) Connect the other RF signal generator (with the out-
put disabled) to the RXMXIN SMA connector. Set
the frequency to 1.9GHz and the amplitude to
-30dBm.
4) Connect the spectrum analyzer to the IF SMA con-
nector. Set the spectrum analyzer to a 400MHz cen-
ter frequency, a 200MHz total span, and a 0dBm
reference level.
5) Turn on the LO signal generator and the RF signal
generator.
6) The downconverted output signal at 400MHz is visi-
ble on the spectrum analyzer, indicating a mixer
conversion gain of 8.4dB after accounting for cable
and balun losses. The balun loss is typically 1dB at
400MHz.
_______________Detailed Description
This section describes the MAX2406 EV kit circuitry.
For more detailed information about the operation of the
device itself, please consult the MAX2406 data sheet.
Low-Noise Amplifier
The LNA circuitry consists of two DC-blocking capacitors:
one at the input (C13) and one at the output (C8). A shunt
capacitor (C15) provides a simple matching network to
improve the input return loss.
Local Oscillator
The MAX2406 EV kit’s LO input requires only a DC block-
ing capacitor (C3). No other circuitry is needed. For more
information on the LO port, including the optional use of a
differential LO source, consult the MAX2406 data sheet.
Mixer Input
The receiver mixer’s input (RXMXIN) requires a simple
matching network. Capacitor C6 and inductor L5 are
used to match the input pin to 50Ω, while C7 provides
DC blocking.
IF Output
The MAX2406 has a differential IF output port (IF and IF)
that can be used either in a differential or single-ended
configuration. The EV kit uses a differential configuration.
The balun (L3) converts the MAX2406’s differential output
signal into a single-ended signal compatible with 50Ω test
equipment. The balun is not required in a typical applica-
tion. Inductors L1, L2, L6, and L7 provide DC bias and an
impedance-matching network. Please note that the match-
ing network is frequency selective and must be changed
for operation at other IF frequencies. Consult the MAX2406
data sheet for a plot of IF output impedance versus fre-
quency. Capacitors C4 and C5 provide DC blocking. The
balun (L3) provides the differential to single-ended conver-
sion with about 1dB of loss at 400MHz. The IF output sig-
nal is then connected to the IF SMA connector. Resistors
R2 and R3 (0Ω) and inductor L4 (not installed) are provid-
ed as pads on the EV kit’s PC board layout for experimen-
tation, if desired.
______________________________Layout
A good PC board layout is an essential part of an RF
circuit design. The EV kit’s PC board can serve as a
guide for laying out a board using the MAX2406.
Each VCC node on the PC board has its own decou-
pling capacitor. This minimizes supply coupling from
one section of the MAX2406 to another. A star topology
for the supply layout, in which each VCC node on the
MAX2406 circuit has a separate connection to a central
VCC node, can further minimize coupling between the
LNA and mixer sections of the MAX2406.
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