Preliminary Results on a Compact Duplexer Design for K/Ka-Band SatCom on the Move User Terminals

Preliminary results on a compact duplexer design for K/Ka-Band for Satcom on the move user terminals are presented. The proposed duplexer is embedded into a package stack-up composed by five dielectric core layers and ten metal layers and it will be integrated with RF chips and antenna element to form an Antenna Front End (AFE). The duplexer functionality is that to split the TX and RX signals, making the antenna using two different paths for transmitting and receiving purpose. The target frequencies are 19.2-21.2 GHz for RX bandwidth and 28-31 GHz for TX bandwidth. The duplexer has been designed using two elliptic bandpass filters, one for TX and one for RX bandwidths. The duplexer is very compact, as its size is only 2.85 mm x 2.8 mm. The simulated Reflection losses are less than 10 dB results, from 19.2 GHz to 20.4 GHz, in RX bandwidth, and from 28.2 GHz to 30.5 GHz in TX bandwidth. The Insertion losses level is approximately 1.5 dB within the bands of interest. The rejection level is approximately -38 dB in RX bandwidth. From these preliminary results, it is possible to state that the proposed duplexer can be very suitable for Satcom systems in K/Ka-band, as its compactness will provide easy feasibility for the integration of the duplexer, with the RF chips and the antenna elements in an Antenna Front End.