A Compact Active Phaser with Enhanced Group Delay Linearity for Analog Signal Processing

This paper presents a wideband compact phaser with a linear group delay, a key block to many Analog Signal Processing applications as Real-Time Fourier Transforming systems (RTFT). The phaser, designed in a 130 nm BiCMOS technology, presents a group delay dispersion of 3 ns, a layout area of only 30 μm by 330 μm and power consumption of 7.2 mW. Between 300 MHz and 2.5 GHz, the linearity error of the group delay is lower than 5%. The enhanced linearity of the group delay has been obtained thanks to an association of active first-order all-pass filters and active second-order all-pass filters. The benefit of using exclusively active components are the reduced layout area and the signal amplification achieved by the phaser.