Whats the difference between a resonant modulator and a broadband modulator?
A resonant modulator operates at a specified frequency while a broadband modulator can operate over a wide frequency range. In a resonant modulator, the crystal is placed in a resonant circuit or cavity tuned to a particular frequency. Because the crystal voltage can be more than ten times the input drive voltage when operating near that particular frequency, resonant devices require significantly lower input voltage, and are easier to operate than broadband modulators. Keep in mind that the resonant frequency of the Model 4001 and 4003 modulators isn’t tunable. Typically the resonance has a bandwidth of 2-4% of the resonant frequency, allowing the device to be operated over this narrow frequency range. In contrast, the high-frequency resonant cavity modulators (Models 442X, 443X and 485X) are equipped with a tuning screw that allows the resonant frequency to be adjusted over a 100-MHz range. To compare the advantages of resonant enhancement, we can compare the half-wave voltage, Vp, t
