A coupled-line balun for ultra-wideband single-balanced diode mixer

M. Y. Algumaei (Universiti Teknikal Malaysia Melaka (UTeM))
N. A. Shairi (Universiti Teknikal Malaysia Melaka (UTeM))
Z. Zakaria (Universiti Teknikal Malaysia Melaka (UTeM))
A. M. Zobilah (Universiti Teknikal Malaysia Melaka (UTeM))
N. Edward (Universiti Teknikal Malaysia Melaka (UTeM))

TELKOMNIKA (Telecommunication Computing Electronics and Control)
Vol 17, No 1: February 2019

A multi-section coupled-line balun design for an ultra-wideband diode mixer is presented in this paper. The multi-section coupled-line balun was used to interface with the diode mixer in which it can deliver a good impedance matching between the diode mixer and input/output ports. The mixer design operates with a Local Oscillator (LO) power level of 10 dBm, Radio Frequency (RF) power level of -20 dBm and Intermediate Frequency (IF) of 100 MHz with the balun characteristic of 180° phase shift over UWB frequency (3.1 to 10.6 GHz), the mixer design demonstrated a good conversion loss of -8 to -16 dB over the frequency range from 3.1 to 10.6 GHz. Therefore, the proposed multi-section coupled-line balun for application of UWB mixer showed a good isolation between the mixer’s ports.