Impedance tuner using BST varactors in alumina-based IPD technology

A compact, low loss and wide coverage impedance tuner using alumina-based integrated passive device (AIPD) technology is proposed. By integrating a tuning element-barium strontium titanate (BST) varactor, with high-Q AIPD L-C elements, an impedance tuner with wide impedance coverage range is achieved while maintaining low insertion losses. Details of the in-house AIPD fabrication process are presented. Measured results for a continuous impedance tuner designed at 2.5 GHz are presented demonstrating a maximum insertion loss of 1.2-dB impedance tuner from 2-3 GHz. The overall footprint of the chip is only 3.8 mm × 1.88 mm.