An Electrical Balance Duplexer for FDD Radios that Isolates TX from RX Independently in Two Bands

An Electrical Balance Duplexer (EBD) supports dual-band TX-RX isolation enabling FDD operation at 5–7 GHz for Wi-Fi 6/6E. A programmable network in the EBD can balance the antenna impedance (
$Z$
ANT) in the TX channel and RX channel independently. The EBD provides > 40 dB isolation in an 80 MHz channel bandwidth in the TX band (5–6 GHz), for any
$Z_{\text{ANT}}(f_{\text{TX}})$
within
$\text{VSWR} =2$
, and independently in the RX band (6–7 GHz) when
$Q_{\text{ANT}}< 4.3$
. The EBD is designed for < 4 dB RX IL and < 3.8 dB TX IL, and it supports +29 dBm TX output.