Fast X-Band Phase Shifter

New Low-Loss Ferroelectric Materials for Accelerator Applications

“…The key element of the active DLDS is a high power microwave switch, which must quickly divert ~500 MW of power sequentially from a main feed line in and out of the accelerator modules. The possible switch design may contain an electrically-controlled phase shifter as the active element [15]. In order to switch RF power from the feed line to the accelerator structure, the phase shifter has to change the signal phase by 180°.…”

“…Bulk ferroelectric materials can be used as key elements of the tunable and switching accelerator components provided the dielectric constant of the material is in the range of 400-500 or less, loss tangent at 10 GHz does not exceed (2-5)×10 -3 and the tunability factor (defined as a ratio of the dielectric constant at zero biasing field to that at a specific applied electric field) is in the range of 1.15-1.20 at a 5 V/µm (50 kV/cm) biasing field [13][14][15]21]. The time response of the switching components is a critical issue for accelerator applications as well and it should not exceed 10 -9 -10 -10 sec for the entire device [13][14][15]. Even smaller switching times would be desirable.…”

“…Fig. 3 shows a BSTM ring of 4 cm diameter formed and sintered for the fast ferroelectric switch and phase-shifter prototypes [13][14][15].…”

“…The critical requirement for ferroelectrics for successful linear colliders applications is a loss tangent no larger than 10 -3 at 11 GHz [14,15].…”

“…The use of ferroelectric components has been recently proposed for both classes of linear collider active components [13][14][15], based on BST ceramic rings used to partially load cylindrical cavities. The critical requirement for ferroelectrics for successful linear colliders applications is a loss tangent no larger than 10 -3 at 11 GHz [14,15].…”