RF Electronics Chapter4: Transmission Line Transformers and Hybrids Page 101
2022, C. J. Kikkert, James Cook University, ISBN 978-0-6486803-9-0.
Figure 4.61 Basic and Marchand Balun phase response.
Marchand Balun Realisation
The original Marchand Balun was designed using coaxial lines, and for convenience,
coaxial lines are used to explain their operation in figures 4.58 to 4.61. For low power
applications, Stripline, Microstrip, LTCC or MMIC configurations are preferred. A
Microstrip circuit would give the lowest cost realisation. Because a large amount of
coupling is required between the tracks, Lange type couplers will need to be used.
Figure 4.62 Lange Marchand Circuit (5 track).
The Lange coupler in figure 4.48 has half-length tracks at the edges and the same number
of fingers for both lines to be coupled. For this Balun, three fingers (W1, W3 and W5)
are used for the lines that are grounded at one end and two fingers (W2 and W4) are used
for the other lines. Their widths (WL1 to WL4) can be made different. Those couplers
can be realised using M5CLIN elements as shown in Figure 4.62. To compare the
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