MONOLITHIC PLANAR QUADRATURE HYBRID

Publishing Venue

Motorola

Related People

Abstract

In accordance with standard practice, the word "hybrid' as used here also means "hybrid power divider/ power combiner? The hybrid is ideally a four-port, lossless, reciprocal, and symmetrical network in which the vector sum of two sinusoids, each incident on one of two ports, appears at a thud port, and the vector dif- ference of the incident sinusoids appears at the fourth port. Hybrids are used for linear power division, power combining, and phase shitlmg in larger functional blocks such as mixers, phase comparators, and other applica- tions requiring vector processing of audio, W and micro- wave signals.

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MOTOROLA INC. Technical Developments Volume 16 August 1992

MONOLITHIC PLANAR QUADRATURE HYBRID

by David R. Lang

  In accordance with standard practice, the word "hybrid' as used here also means "hybrid power divider/ power combiner? The hybrid is ideally a four-port, lossless, reciprocal, and symmetrical network in which the vector sum of two sinusoids, each incident on one of two ports, appears at a thud port, and the vector dif- ference of the incident sinusoids appears at the fourth port. Hybrids are used for linear power division, power combining, and phase shitlmg in larger functional blocks such as mixers, phase comparators, and other applica- tions requiring vector processing of audio, W and micro- wave signals.

  In monolithic microwave integrated circuits, (MMIC) the available size precludes the use of traditional broadband coupled transmission line hybrids at lower frequencies. Physically simple structures which behave approximately as individual lumped capacitors and induc- tors are therefore preferred for the realization of passive MMIC networks.

that the even-mode capacitance of the coupled line pair must be duplicated in some way in the lumped element equivalent circuit by capacitors connected to the hybrid ground reference.

  The new hybrid described here does not require any capacitance to the ground reference. This confers a signiticant fabrication advantage over previous designs when realizing the hybrid on a planar substrate such as alumina or ga...