Millimeter-Wave Signal Integrity
Millimeter-wave signal integrity addresses the unique challenges of propagating electromagnetic energy at frequencies from 30 GHz to 300 GHz, where wavelengths range from 10 mm down to 1 mm. At these extreme frequencies, phenomena that are negligible at lower frequencies become dominant factors in system performance. Parasitic inductances and capacitances of just a few femtohenries or femtofarads can significantly impact circuit behavior, and physical dimensions that seem microscopically small can represent significant fractions of a wavelength.
The millimeter-wave regime represents a transition zone between traditional microwave circuit theory and optical/quasi-optical approaches. Conventional lumped-element circuit models break down completely, and even distributed transmission line models must be enhanced to account for surface waves, radiation losses, dispersion, and higher-order propagation modes. Success in this frequency range requires careful attention to material properties, three-dimensional electromagnetic field distributions, packaging parasitics, and sophisticated measurement and characterization techniques.