A Compact Broadband Marchand Balun for Millimeter-wave and Sub-THz Applications

M. Hossain1, T.K. Johansen2, M. Hrobak3, W. Heinrich1, V. Krozer1

Published in:

13th German Microwave Conference (GeMiC 2020), Cottbus, Germany, Mar. 09-11, ISBN 978-3-9820397-1-8, pp. 60-63 (2020).

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Abstract:

This paper presents a compact broadband millimeter-wave Marchand balun, realized using indium phosphide (InP) transferred substrate (TS) technology. The architecture of this balun is based on a folded-type Marchand balun, modified using a compensating transmission line. The core area of the balun is 0.35 × 0.16 mm2 for operation at W-band. The measured results show a corrected insertion loss of less than 7.5 dB and a return loss better than 10 dB in the frequency range from 70 to 110 GHz. Amplitude and phase imbalance remain below 2 dB and 2.5 degrees, respectively, over a 40 GHz bandwidth. To the authors' knowledge, this is the highest RF center frequency published so far for a broadband Marchand type balun with low phase and magnitude imbalance.

1 Ferdinand-Braun-Institut, Leibniz-Insitut für Höchstfrequenztechnik (FBH), Berlin, Germany
2 Technical University of Denmark, Kgs. Lyngby, Denmark
3 Continental Automotive GmbH, Munich, Germany

Keywords:

Balun, indium phosphide (InP), millimeterwave, MMIC, transferred-substrate technology.