Distributed phase shifter with pyrochlore bismuth zinc niobate thin films

Abstract

Abstract-A monolithic Ku-band phase shifter employing voltage tunable Bi1.5Zn1.0Nb1.5O7 (BZN) thin film parallel plate capacitors is reported. BZN films were deposited by RF magnetron sputtering on single-crystal sapphire substrates. A nine-section distributed CPW loaded-line phase-shifter structure was designed. A differential phase shift of 175° was achieved with a maximum insertion loss of 3.5 dB at 15 GHz, giving a figure of merit ~ 50°/dB. To the best of our knowledge, this is the first demonstration of a monolithic tunable microwave circuit using BZN thin films.

Barium strontium titanate thin film varactors for room-temperature microwave device applications

“…These values are comparable to those found in ceramic BZN and also comparable to the best values reported for BST thin films [140]. A monolithic K-band phase shifter employing BZN parallel plate capacitors was demonstrated with a figure of merit of about 50 • dB −1 [141]. However, the high tunability of BZN can only be realized under very high electric fields.…”

A Distributed Phase Shifter Using Bi 1.5 Zn 1.0 Nb 1.5 O 7 /Ba 0.5 Sr 0.5 TiO 3 Thin Films

“…[5] Bi 1.5 Zn 1.0 Nb 1.5 O 7 (BZN) thin films are other tunable dielectrics which exhibit very low dielectric loss (tan𝛿 < 0.0005), [6] and the low insertion loss of a phase shifter using BZN thin films has been reported. [7] BZN thin films are attractive for low loss microwave applications, whereas it is very difficult to prepare BZN with high tunability and it requires very high electric fields to achieve a high tunability.…”