In this paper, a symmetric four-port microwave varactor based 90° directional coupler with
tunable coupling ratios and reconfigurable responses is presented. The proposed coupler is …

This paper presents the design, fabrication, and measurement of a reconfigurable
quadrature hybrid coupler and a tunable low-loss reflective-type phase shifter built using the …

This paper presents a tunable CMOS directional coupler that utilizes lumped-element LC
sections. The lumped-element approach used to build the directional coupler makes it …

This paper presents a highly reconfigurable, low-power, and compact directional coupler.
The coupler uses varactors and novel active inductors to achieve wide tuning ranges of …

A tunable dual-band quadrature hybrid coupler for mobile GSM bands (900 and 1800MHz)
is proposed and characterized. The structure is composed of four quarter-wavelength …

Wireless communication and sensing applications seek higher frequencies to enable higher
data rates or more precise localization using a wider modulation bandwidth. Particularly, 6G …

A method for tuning the centre frequency of a 3 dB hybrid coupler using varactor diodes is
presented. The circuit is suitable for reconfigurable or multifunction transceivers that switch …

In this paper, a compact coupled-line trans-directional (TRD) coupler with wide continuous
frequency tuning range and superior performance is presented. The proposed tunable TRD …

This paper presents an approach for the systematic design of reconfigurable quadrature
directional couplers. From even-odd-analysis of four-ports with two-fold symmetry four …

This paper presents the analysis and development of compact cascaded directional
couplers with continuously tuneable coupling ratios. The general approach of cascading two …