Search

Summary

In this chapter, we describe four realized examples of discrete-time receivers that are largely based on the architecture and circuitryintroduced in previous chapters. Starting with a commercial DT receiver designed for GSM single-chip radios, which introduces the novel low-pass IIR filter, we then continue with three highly reconfigurable superheterodyne receivers that employ the complex IQ charge-sharing band-pass filter (BPF) for image rejection.

To achieve a high IIP2 level on a mixer, static calibration techniques have been developed. Most of them are based on an intentional introduction of a calibrated mismatch in the structure of the mixer. They are performed at production stage. It is also possible to automate them but their activation is strongly limited in portable devices because of system restrictions. Furthermore, IIP2 is sensitive to system variations, thereby degrading the calibration operation. The challenge is so to make the calibration system dynamic, i.e. performing an online calibration. This paper presents a perturbance-based algorithm as part of an automatic calibration system to track the optimum IIP2 level. Measurements validate the algorithm behavior and indicate the feasibility of using it in a complete calibration system for a future on-chip implementation.

Search Results

Refine search

Refine search

Actions for selected content:

2 results

5 - Discrete-Time Receivers: Case Studies

Summary

Improved IP2 calibration method using a perturbance-based algorithm

Search Results

Refine search

Refine search

Actions for selected content:

Save Search

2 results

5 - Discrete-Time Receivers: Case Studies

Summary

Improved IP2 calibration method using a perturbance-based algorithm