Table 1: Comparison of tunable components.

Tunable componentAdvantagesDisadvantages

MEMSReduced insertion loss, good isolation, extremely high linearity, low power losses, consumes little or almost no DC power, wide bandwidthNeed high-control voltage (50–100 V), poor reliability due to mechanical movement within the switch (0.2–100 µs), slow switching speed, discrete tuning, limited lifecycle
PIN DiodeNeeds very low driving voltage, high tuning speed (1–100 ns), high power handling capability, very reliable since there are no moving part, extremely low costNeeds high DC bias current in their on state which consumes a significant amount of DC power, nonlinear behavior, poor quality factor, discrete tuning
VaractorThe current flow through the varactor is small compared to PIN diode or MEMS, continuous tuningVaractors are nonlinear and have low dynamic range, and complex bias circuitry are required