Journal article
On the amplitude and phase errors of quadrature LC-tank CMOS oscillators
An analytic approach for the estimation of the phase and amplitude imbalances caused by component mismatches and parasitic magnetic fields in two popular quadrature LC oscillators is presented. Very simple and closed-form equations are derived, proving that, although the two topologies share the same small signal circuit, they display very different sensitivities to the mentioned sources of imbalance.
Moreover, it is shown that parasitic inductors coupling, overlooked up to date, plays a key role ultimately limiting the achievable phase accuracy. The theoretical results are verified through extensive simulations and measurements on a 1.7-GHz quadrature oscillator and frequency up-converter implemented in a 0.18-μm CMOS process.
| Language: | English |
|---|---|
| Publisher: | IEEE |
| Year: | 2006 |
| Pages: | 1305-1313 |
| ISSN: | 1558173x and 00189200 |
| Types: | Journal article |
| DOI: | 10.1109/JSSC.2006.874333 |
Amplitude estimation CMOS integrated circuits CMOS oscillator CMOS process CMOS radio frequency integrated circuits Circuit topology Coupling circuits Differential equations Displays Inductors Magnetic analysis Magnetic fields Oscillators Phase estimation amplitude error amplitude imbalance component mismatch frequency up-converter image rejection local oscillators parasitic inductor coupling parasitic magnetic field phase accuracy phase error phase imbalance quadrature LC oscillator quadrature LC tank quadrature voltage-controlled oscillators (QVCOs) radiofrequency oscillators small signal circuit voltage-controlled oscillators
