High-frequency EPR applications of open nonradiative resonators

Open single-mode cavities for millimeter and submillimeter wavelengths

“…3. The unloaded quality factor of the mode, calculated from the loaded quality factor of the resonance [6], is Q 0,TE011 =3300, which compares well with the values reported in literature [7]. Another characteristic of the non-radiative resonators operating on the TE 011 mode is their minimal active volume, despite the largely open structure.…”

“…The holes are closed by plungers, allowing the tuning of the resonance frequency. The excitation is obtained through the evanescent field that extends along the plates [6]. An assembled view of the cavity is shown in Fig.…”

“…The electromagnetic absorption at the resonance was determined with a reflection configuration [6]. The related propagation circuit is shown in Fig.…”

“…This latter decouples the incoming radiation from the reflected one, which propagates towards the detector. The variation in the background signal, due for instance to the standing waves, is minimized through a normalization procedure [6]. …”

“…Single-mode resonators based on non-radiative structures have been introduced with the aim to overcome the main drawbacks of the conventional resonators at millimeter wavelengths [3]. They have recently been employed in electron paramagnetic resonance and dynamic nuclear polarization studies at 95 GHz [4,5]. This contribution presents some recent results at the border of the submillimeter wavelengths.…”