Complete Design and Measurement Methodology for a Tunable RF Impedance-Matching Network
Résumé
This paper presents the design, fabrication, and characterization of a compact narrowband tunable impedance-matching network. A prototype was fabricated in hybrid technology using coplanar waveguide transmission lines and surface-mounted components. The network consists of a II-structure with tunable components made of varactors in series with inductors. Simulations and measurements are in good agreement. A new measurement methodology suitable for tunable impedance-matching networks is proposed. The results show that complex impedances with magnitudes varying from 6 Omega to 1 kOmega can be matched at 1 GHz and tuned in a 50% bandwidth. In addition, nonlinear measurements were done to fully characterize the network. The 1-dB compression point is reached at an input power of 20 dBm, while the input power for the third-order intermodulation intercept point is 21.3 dBm for a 1-kHz offset between the two input frequencies.
Mots clés
Fabrication
Transmission line measurements
Surface impedance
identification
impedance matching
UHF circuits
varactors
RF impedance-matching network
coplanar waveguide transmission lines
intermodulation intercept point
resistance 6 ohm to 1 kohm
bandwidth 1 GHz
Design methodology
Impedance measurement
Radio frequency
Narrowband
Prototypes
Surface-mount technology
Coplanar waveguides
Coplanar waveguide
impedance-matching network
reconfigurable
tuner