Rf Port Interface; Overview - Analog Devices AD9361 Reference Manual

AD9361 Reference Manual

RF PORT INTERFACE

OVERVIEW

The purpose of this section is to define the expected
port impedance values and potential impedance matching
techniques.
The AD9361 has with two independent receive paths and two
independent transmit paths. Each receive path has three (A, B,
and C) LNA inputs and each transmit path has two (A and B)
Tx outputs. The LNA inputs and Tx outputs require external
impedance matching networks. The receiver LNA input ports
may be utilized in either a single-ended mode or differential
mode. The transmitter output ports may only be utilized in a
differential mode.
It is critical to have these interfaces working properly to achieve
data sheet performance levels. The main considerations are as
AD9361
follows:
•
Rx interface type: single ended or differential?
•
Device to be interfaced: such as, filter, balun, T/R switch,
external LNA, external PA: Short to ground at DC?
•
Rx LNA maximum (no damage) input power ( +2.5 dBm
Peak: single-ended: lossless match: 50 Ω source).
•
Rx LNA input port DC voltage level (~ +0.6 V
•
Tx output port bias (+1.3 V
maximum output power).
•
Board design: such as reference-planes, transmission lines,
impedance matching.
Rev. A | Page 61 of 128
UG-570
).
DC
@ 75 mA per side @
DC