Book contents
- Frontmatter
- Contents
- Notation
- Preface
- 1 Introduction to Highly Integrated and Tunable RF Receiver Front Ends
- 2 Active Blocker-Cancellation Techniques in Receivers
- 3 Impedance Transformation: Introduction to the Simplest On-Chip SAW Filter
- 4 Four-Phase High-Q Bandpass Filters
- 5 M-Phase High-Q Bandpass Filters
- 6 Design of a Superheterodyne Receiver Using M-Phase Filters
- 7 Impact of Imperfections on the Performance of M-phase Filters
- 8 M-phase Filtering and Duality
- Appendix A
- References
- Index
7 - Impact of Imperfections on the Performance of M-phase Filters
Published online by Cambridge University Press: 05 July 2013
- Frontmatter
- Contents
- Notation
- Preface
- 1 Introduction to Highly Integrated and Tunable RF Receiver Front Ends
- 2 Active Blocker-Cancellation Techniques in Receivers
- 3 Impedance Transformation: Introduction to the Simplest On-Chip SAW Filter
- 4 Four-Phase High-Q Bandpass Filters
- 5 M-Phase High-Q Bandpass Filters
- 6 Design of a Superheterodyne Receiver Using M-Phase Filters
- 7 Impact of Imperfections on the Performance of M-phase Filters
- 8 M-phase Filtering and Duality
- Appendix A
- References
- Index
Summary
Introduction
Although a high-Q M-phase filter has a simple structure, there are numerous implementation-related imperfections that must be scrutinized carefully and evaluated for their impact on the filter. The phase noise of the LO clocks, the second-order nonlinearity of the switches, the phase error between the LOs, and the harmonic downconversion and thermal noise of switches are examples of some of these imperfections. We will examine the impact of these imperfections in this chapter. For the sake of simplicity, we will discuss the effects of these imperfections in the four-phase bandpass filter but will apply our findings to the M-phase high-Q bandpass filters.
Mathematical background
In the context of analyzing the effects of imperfections, we will encounter repeatedly the switching system in Fig. 7.1 in which the input is a voltage source υU(t) in series with an M-phase high-Q frequency-translated bandpass filter, and the response is the voltage across the RF impedance ZL. Although it is drawn single-ended, the actual implementation is assumed to be differential. The voltage υU(t) (U stands for unwanted) models an unwanted voltage that emerges from the imperfections and could have components everywhere, including locations around the clock frequency and its harmonics. Because this unwanted voltage is manifested from imperfections, it is usually a weak signal that does not cause large voltage swings across ZL. The impedance ZL is the equivalent Norton or Thevenin impedance seen from the RF node where the high-Q filter is connected.
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- Information
- Integration of Passive RF Front End Components in SoCs , pp. 140 - 163Publisher: Cambridge University PressPrint publication year: 2013