A Compact RF Front-End SiP With Improved Harmonic Suppression for Dual Polarization Phased Array Radar

This letter presents a compact
${C}$
-band front-end module for dual polarization (DP) radar. The module is integrated in the form of system in package (SiP) using high-temperature co- fired ceramic (HTCC) process, which integrates a limiter-low-noise amplifier (L-LNA), a power amplifier (PA), a single pole double throw (SPDT) switch, a switch driver, a circulator, a power management circuit, and so on. The proposed DP SiP uses a cascaded switch and circulator topology to provide a horizontal polarization (HP) channel and a vertical polarization (VP) channel with one transmit/receive (T/R). Moreover, it integrates a compact HTCC filter to improve the second harmonic suppression (SHS) caused by the nonlinearity of SPDT switch at high output power. The measurement results show that the output power of the SiP is over 40.5 dBm with more than 40% power added efficiency (PAE), the noise figure (NF) is less than 3.1 dB, and the SHS is less than −50 dBc for both polarization channels. The transmit and receive characteristics of both polarization channels have high consistency. The dimension of the SiP is
$19.0\times 13.0\times4.3$
mm3.