DSP-Driven Self-Tuning of RF Circuits for Process-Induced Performance Variability

Abstract

In the deep-submicrometer design regime, RF circuits are expected to be increasingly susceptible to process variations, and thereby suffer from significant loss of parametric yield. To address this problem, a postmanufacture self-tuning technique that aims to compensate for multiparameter variations is presented. The proposed method incorporates a "response feature" detector and "hardware tuning knobs," designed into the RF circuit. The RF device test response to a specially crafted diagnostic test stimulus is logged via the built-in detector and embedded analog-to-digital converter. Analysis and prediction of the optimal tuning knob control values for performance compensation is performed using software running on the baseband DSP processor. As a result, the RF circuit performance can be diagnosed and tuned with minimal assistance from external test equipment. Multiple RF performance parameters can be adjusted simultaneously under tuning knob control. The proposed concepts are illustrated for an RF lownoise amplifier (LNA) design and can be applied to other RF circuits as well. A simulation case study and hardware measurements on a fabricated 1.9-GHz LNAs show significant parametric yield enhancement (up to 58%) across the critical RF performance specifications of interest.

A linearized, low-phase-noise VCO-based 25-GHz PLL with autonomic biasing

“…7 Instead of directly measuring the phase noise, it has been proposed in [4] that phase noise can be predicted from other easily measurable parameters using linear regression. Similar methods based on alternate tests have been proposed in the past for other RF circuits [15], [16]. In this work, we implement a digitally 7 For example, the phase-noise sensor in [13] achieves 75-dBc sensitivity at 100-kHz offset from a 2-GHz carrier, corresponding to a sensitivity of 95 dBc at 10-MHz offset from a 20-GHz carrier, which is unusable for the present VCO.…”

“…This range covers operation over 22. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. 4 GHz, with margin, meeting requirements for a 60-GHz superheterodyne radio [2].…”

Research on the Optimization and Ascension of Target Accuracy for RF Systems

“…The Fig. 2 shows the schematic of the cascode LNA with inductive source degeneration from our previous work, in which this subthreshold LNA with linearity enhancement was proposed [8]. The transmitter consists of pseudorandom bit sequence generators, which generate bit sequence, which is fed to coder to produce an electrical coded signal.…”

“…For example, in an envelope detector [6], analog-to-digital converter (ADC), and digital signal processor is used for the calibration. In [7][8][9][10][11][12][13] in addition, it puts forward the evaluation of the output spectrum of the envelope detector output connected to reduce the extraction of the third order distortion, which requires a single chip implementation of FFT engine.…”

“…In this study, the numerical control self-calibration in figure 1 is developed IM3 estimate rf cutting and automatically adjust the best IM3 performance. [8] the low noise amplifier topology are used to demonstrate the function of the BIC system is put forward. It includes the digital switches allow IM3 tuning.…”