ML13146
LANSDALE Semiconductor, Inc.
The linear gain of the Mixer/Buf when used as a buffer is
approximately –5.0 to –8.0 dB.
Mixer/Buffer Outputs
The mixer outputs (Mixer/Buf Out + and Mixer/Buf Out –)
are balanced, open collector. A shunt resistor of 200 Ω mini-
mum to V
is recommended for stability.
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The outputs can be used as a single–ended driver or con-
nected in a balanced–to–unbalanced configuration. If the sin-
gle–ended driver configuration is used, the unused output must
be tied directly to V . For the balanced–to–unbalanced con-
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figuration, an additional 3.0 to 6.0 dB of power gain can be
achieved. Conjugate matching is easily accomplished to the
desired load by the addition of a shunt and series element (see
Table 2, S22 parameters).
Mixer/Buffer Input
Low Power Amplifier (LPA)
The Mixer/Buf In pin is a broadband, 50 Ω input used to
drive the IF port of the mixer (see Table 2, S11parameters).
The Mixer/Buf In pin can be used in one of three modes:
1. A IF signal can be applied to this pin and up–converted
to the desired RF frequency.
2. A resistor can be connected to ground, controlling the
RF output power.
The LPA is internally biased at low supply current (approxi-
mately 2.0 mA emitter current) for optimal low power opera-
tion, yielding a 10 dBm 1.0 dB output power compression
point. Input and output matching may be achieved at various
frequencies using few external components (see Table 3
S–parameters). Typical power gain is 16 dB with the input/out-
put conjugately matched to the source/load impedance. A mini-
3. A resistor can be connected to V , disabling the entire
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mum 200 Ω shunt resistor from the output to V
is recom-
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mixer.
mended for stability.
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