The absorption investigation in CVD-diamond plates and windows at 50–200 GHz

Dielectric losses in CVD diamonds in the millimeter-wave range at temperatures 300?900 K

“…Figure 4 shows the dependences of tan δ on the frequency f for several CVD-diamond windows by "De Beers" company. For specimens with relatively higher losses related to a greater number of defects (seen with a microscope), we observed that, as in [13][14][15], the losses at frequencies above 150 GHz exceed the values corresponding to the dependence 1/f describing losses due to conductance. Figure 5 shows the temperature dependences of tan δ in the specimen 56 22DB6 at frequencies 136 and 170 GHz.…”

“…Studying dielectric losses in polycrystalline diamonds grown by chemical vapor deposition (CVD) has become very topical in the millimeter-wave range because of considerable progress in the growth technology and the corresponding applications of this previously "exotic" material in modern engineering [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The grown diamond disks have a number of remarkable electrical and mechanical properties:…”

“…These losses are related to defects, impurities, and non-diamond inclusions, i.e., it is in principle possible to significantly decrease the losses by improving the growth technology. In this way, the lowest losses were reduced by 2 orders of magnitude during the last 10 years and continue to decrease [1,[4][5][6][7][8][9][10][11][12][13][14][15]. In the case of the further decrease in losses, it would be possible, e.g., to remove the water cooling system in windows for output and input of electromagnetic energy (see the above discussion), to significantly simplify their design, and thereby to enhance reliability of the entire facility.…”

Measurement of Dielectric Properties for Low-Loss Materials at Millimeter Wavelengths

“…For comparison purposes, the data available on very low-loss materials at frequencies above 100 GHz has come primarily from two laboratories, the Institut für Materialforschung (IMF I) at Forschungzentrum Karlsruhe [11][12][13] and the Institute of Applied Physics (IAP) of the Russian Academy of Sciences [14,15]. Table 3 shows a comparison of our loss tangent values for CVD diamond, sapphire, and quartz, with data from those laboratories.…”

The Influence of a Coupling Film on Ultra-Low-Loss Dielectric Measurement Using an Open Resonator

“…The resonator consists of two plane mirrors, a coupling film orientated at 45 0 to the axis of the resonator, and a dielectric plate placed perpendicular to the axis. Our analytic method is similar to that used by Koposova et al in analyzing an open Fabry-Perot resonator loaded with a multi-layer dielectric plate, but without a coupling film [7]. In Fig.…”