True or False: The RF impedance level of IMPATT diodes is generally lower than that of Gunn diodes.

Introduction / Context:
Gunn and IMPATT diodes are common solid-state microwave sources but operate on different physical principles and present different device impedances to resonant circuits or transmission lines.

Given Data / Assumptions:

• Typical Gunn diode impedances are relatively low (a few to a few tens of ohms).
• Typical IMPATT diode impedances are higher (tens to hundreds of ohms), depending on design and frequency.

Concept / Approach:
Gunn diodes (transferred electron effect) are commonly matched using low-impedance resonant circuits, while IMPATT diodes (avalanche transit-time) exhibit higher negative resistance magnitude and effective impedance, thus often require different matching networks. Therefore, the statement that IMPATT has “lower” impedance than Gunn is incorrect.

Step-by-Step Solution:

Verification / Alternative check:
Device application notes and oscillator design examples routinely show low-Q, low-Z resonators for Gunns, whereas IMPATT oscillators use higher-Z matching networks or resonators.

Why Other Options Are Wrong:

Common Pitfalls:

Final Answer: