JUNCTION BRANCH LINE COUPLER FOR RADAR S-BAND 3 GHZ

Abstract

Branch Line Couplers have an important role in various RF systems such as transmitters, receivers,
signal processing circuits, phase shift, coupling.This research discusses the design of the microstrip 3
dB Branch Line Coupler with π-junction that works at a frequency of 3 GHz using FR4 substrate.
The design was carried out with the help of simulation software Computer Simulation Technology
2019. Branch Line Coupler is part of a duplexer to be applied to a pulse radar operating at a
frequency of 3 GHz, while the insertion loss to be achieved is <1 dB, isolation between ports to be
achieved <- 20 dB, the amount of VSWR to be achieved is ≤ 1.5 and the coupling factor to be
achieved is -3 dB.The results of this research are the microstrip branch line coupler that is designed
to work at a frequency of 3 GHz using the EPOXY FR4 substrate, εr = 4.6 from the simulation, the
return loss value (S11) = -61.46 dB, Insertion loss (S21) = -3.29 dB, Coupling Factor (S31) = -3.66
dB, Insulation Value (S14) = -31.12 dB.