Kl. Chan et al., A QUADRATURE-HYBRID DESIGN USING A 4-PORT ELLIPTIC PATCH, IEEE transactions on microwave theory and techniques, 45(2), 1997, pp. 307-310
Available designs of quadrature hybrids have used transmission lines,
and recently, circular-disk patches, This paper introduces a four-port
quadrature hybrid using a microstrip elliptic patch. It is shown that
this configuration has good performance as a quadrature hybrid over a
fairly large bandwidth, The performance is improved by the introducti
on of matching networks, The analysis is carried out using the cavity
model Green's function with appropriate corrections for the fringing f
ields, A comparison of experimental and theoretical results show good
agreement.