Microstrip Ring Hybrid Coupler

I. Theory

1) Structure [Naver blog, Kseo]

II. Application

1. Tx-Rx isolation (송수신 분리)

Park, "UHF-band RFID reader front-end architecture using ring-hybrid for near-field applications, 41st EuMC,

https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6101774

2. Monopulse comparator (모노펄스 비교기)

Microwave 101, Monopulse Comparator Netowrks, https://www.microwaves101.com/encyclopedias/monopulse-comparator-networks

3. Single-balanced mixer (단일평형 혼합기)

Lai, "Implementation of a quadrature hybrid for miniature mixer application", MOTL, 51(8), 1843-1845, 2009

III. Laboratory

Pavithra, "Design of compact 180 degree hybrid coupler using T-shape structure", PETEAM 2018

ㅇ 기판: FR-4, h = 1.6 mm, ε_r = 4.4, tanδ, t = 0.034 mm

1. Make the structure

2. Simulate for the scattering parameters [S]

3. Plot the magnitude of scattering parameters

Reflection in dB: S11, S22

Transmission in dB for summation: S21, S31

Transmission in dB for subtraction: S34, S42

Isolation in dB: S41

4. Plot the phase of scattering parameters.

Transmission phase in degrees for summation: S21, S31

Transmission phase in degrees for subtraction: S34, S42

5. Compare the results at the center frequency 2.4 GHz with the ideal characteristics of the ring hybrid coupler.