Normalized scattering parameters of a two-port circuit terminated in arbitrary impedances are derived and design equations of directional couplers for impedance transforming are derived. To verify the design equations, a microstrip directional coupler is designed at a center frequency of 2GHz, fabricated on a substrate (epsivr=3.5,H= 30mil, tandelta= 0.04) and measured. The measured performance shows good agreement with the simulated one
Published in:
Microwave and Wireless Components Letters, IEEE
(Volume:16
,
Issue:
10
)
Date of Publication: Oct. 2006