Search

Your search keyword '"Ghonoodi, Hojat"' showing total 14 results
Start Over Author "Ghonoodi, Hojat" Search Limiters Available in Library Collection
14 results on '"Ghonoodi, Hojat"'

3. Amplitude Control Loop to Compensate for I/Q Mismatch in an Accurate Quadrature LC Oscillator.

Author

Ghonoodi, Hojat, Hadjmohammadi, Mahsa, and modanlou, Shahram

Subjects
*VOLTAGE-controlled oscillators, *NONLINEAR oscillators, *PHASE noise, *MESOPHASES, *Q technique, *DETECTOR circuits
Abstract

In this paper, a novel parallel-coupled quadrature LC oscillator (PC-QO) is presented that can automatically eliminate imbalances of output phase and amplitude resulting from mismatches in the LC tanks. The method of using unequal coupling factors in a parallel-coupled quadrature oscillator is the base of this design; canceling the phase and amplitude errors takes place by tuning the imbalanced coupling factor using tuneable tail currents. First, the proposed circuit senses the amplitude error and then adjusts the coupling factors according to the situation. We show that using the inversely proportional coupling factors can eliminate the phase and amplitude error simultaneously. In other words, this design uses the amplitude control loop to cancel the phase and amplitude error. The circuit has been simulated using TSMC 0.18 CMOS practical model to confirm the high accuracy of the analysis and capability of the canceling I / Q mismatch technique. The simulation results show that the phase noise of the proposed quadrature voltage controlled oscillator (QVCO) is −123.9 dBc/Hz at 1 MHz offset from 4.4 GHz operation frequency. The total power consumption of the QVCO is 3.4 mW. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

14. A Phase and Amplitude Tunable Quadrature LC Oscillator: Analysis and Design.

Author

GHonoodi, Hojat and Naimi, Hossein Miar

Subjects
*ELECTRIC oscillators, *ELECTRIC equipment, *COMPLEMENTARY metal oxide semiconductors, *DIGITAL electronics, *LOGIC circuits
Abstract

This paper presents a new analytical approach to extract closed form equations for phase and amplitude imbalances raised from mismatches between two LC-tanks in quadrature oscillators. For more generality, we considered different coupling factors for the two coupled LC oscillators. This makes our analysis so general that we could design a phase and amplitude tunable quadrature oscillator accordingly. We show that choosing appropriate inversely proportional coupling factors makes it possible to have exactly zero phase and amplitude errors. Choosing so does not have any impacts on phase noise; indeed, the trade-off between phase noise and phase error in coupled quadrature oscillators has been broken here. We show that using differential stages for tuning tail currents of oscillating stages can somehow implement the inversely proportional coupling factors. Tuning the phase and amplitude errors, the frequency does not change and power consumption remains constant too; these are the advantages of the proposed circuit. The theoretical results and proposed quadrature oscillator are evaluated and confirmed through simulations using TSMC 0.18 \mu\m model technology on a 5-GHz quadrature oscillator with current consumption of 4.2 mA at 1.8 V supply voltage. [ABSTRACT FROM PUBLISHER]

Published
2011
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results