Measured CMOS Reconfigurable Matching Network and its Switched High Quality Capacitor Building Blocks
Peter Sjöblom, Henrik Sjöland · Lund University Publications (Lund University) · 2007
Switched capacitors are here investigated for use in reconfigurable matching networks, particularly for DVB-H frequencies. A $0.13$ $mu$m CMOS circuit is evaluated through both simulations and measurements. Source grounded NMOS transistors are used to switch high quality metal capacitors located above metal layer 8. The quality factor and tuning range depend on frequency, switch voltage, capacitor size, and transistor width. There is a clear trade-off between quality factor and tuning range, and measurements show quality factors above 50, 100, and 150 at tuning ranges of 3.9, 2.4, and 1.6, respectively. A reconfigurable matching network with the switched capacitors has been realized using external inductors and the measured matching domain for the DVB-H frequency band is shown. The total loss of the network is 1.0 dB, a result of the high quality switched capacitors.