A K/Ka-Band Front-End for Dual-Beam, Dual-Polarized Tx/Rx Phased Arrays

This work proposes a front-end in printed circuit board technology (PCB) for phased array terminal antennas at K/Ka-band. The front-end enables full-duplex transmit/receive (Tx/Rx) operation for two polarizations. It supports a single Tx beam and simultaneously two independent Rx beams. The beamforming networks (BNs) are realized with commercially available active semiconductor circuits. Two separate BNs and low noise amplifiers (LNAs) are needed for Rx. Diplexers realized in substrate integrated waveguide (SIW) technology ensure a high Tx/Rx isolation. Thanks to its compactness, the circuit satisfies the half-wave element spacing requirement imposed by array physics for both, Tx and Rx. The measured Rx noise figure remains below 2 dB and the single channel Tx output power exceeds 9 dBm.