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

Abstract

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.

Design of integrated all‐pass filters with linear group delay for analog signal processing applications

“…These two filters form the gate and drain lines of the DAs. The filter conceived by Avignon et al is composed by a cascade of gyrators and first‐order delay cells and presents a monotonic group delay response, where the bandwidth between 800 MHz and 2.5 GHz is considered to be linear to within a 5% error.…”

“…18 More recently, some attempts have been made to implement wideband filters with linear group delay in modern semiconductor technologies. [19][20][21][22][23] Most of the works rely on the on-chip implementation of artificial TLs, that is, the approach considered in the present article. However, the design of such filters remains a core problem, since ASP applications require wideband filters presenting, simultaneously, a very linear group delay and a flat magnitude response.…”

“…More recently, some attempts have been made to implement wideband filters with linear group delay in modern semiconductor technologies . Most of the works rely on the on‐chip implementation of artificial TLs, that is, the approach considered in the present article.…”

A linear group delay filter with tunable positive slope for analog signal processing

“…LGD devices are now also considered for integration in order to obtain compact, low‐power, analog signal processors 5,7,11‐13 . The design of integrated LGD dispersive filters is mainly achieved in two steps.…”