Design of an optimal layout RF passive polyphase filter for large image rejection

Abstract

This article presents the design and implementation of a multi-stage radio-frequency (RF) passive polyphase filter (PPF). The layout parasitics and mismatch which deteriorate significantly the RF filter performance are analyzed and modeled. To reduce this parasitic degradation, a novel optimal layout technique is proposed. It is based on reproducing the same optimized PPF stage layout for the different stages while the desired bandwidth is ensured due to an optimal sizing of the inter-stages connections. This approach has been validated with on chip measurements. Using the proposed techniques more than 55 dB of image rejection over the [1.5; 3.3] GHz bandwidth is demonstrated while achieving zero power consumption and small silicon area in 130nm CMOS technology.

Quadrature broadband phase shift generation using passive RC polyphase filter for RF front-end

“…These receivers have the ability to pre-select and reject the image frequencies. The maximum image rejection depends on the performance of the PPF circuit, thus it is crucial to test its functionality and perform optimization prior to the system level design [18]. The accuracy of RC network will determine the filtering performance.…”

“…The input asymmetric polyphase sequence is composed of two identical pairs of phasors where each pair has the same magnitude but they are separated by 180°. Type II excitation has a loss of about 3dB less than type I [18][20] [24].…”

“…Its RC network is suitable for high frequency design [22]. In radio frequency (RF) applications, the performance of passive polyphase filter in terms of image rejection and quadrature signal generation depends on the component mismatch [18] [19].…”

“…There are various methods to generate the quadrature I/Q signal. For Low-IF architecture, resistor Capacitor polyphase filters are often more favourable thanks to their simple implementation and convenience for high frequency application where high level of integration is required [18]. The capability of RC polyphase filters to provide a required performance in a wide frequency range is critical for the application of double-quadrature low-IF architectures in a multi-standard receiver [24] and transceivers.…”

The design of large image rejection and wideband CMOS active polyphase filter for BeiDou RF receiver

“…In most applications, polyphase filters are divided into passive polyphase filters and active polyphase filters. The passive polyphase cascading several stages can exhibit high image rejection ratio (IRR) and wide bandwidth [12,13,14,15,16,17,18]. However, they should consume more power and occupy more chip area.…”