A Phase Tunable Rotary Traveling Wave Oscillator: Analysis and Calibration

Automatic phase error compensation of rotary traveling wave oscillator: Analysis and design

“…This section provides a brief overview of the basics of the RTWO circuit. 8,13,16 The conventional circuit topology of the RTWO is shown in Figure 1. 8 Four negative transconductors (ÀG m cells) are located at equal intervals at differential outputs for compensating the transmission line losses.…”

“…8,13,16 The conventional circuit topology of the RTWO is shown in Figure 1. 8 Four negative transconductors (ÀG m cells) are located at equal intervals at differential outputs for compensating the transmission line losses. The phase difference of π/N obtains at successive nodes of the RTWO, in which N is the number of -G m cells.…”

“…7 Because of the distributed nature of RTWO, the undesirable parasitic will be absorbed in the synthetic transmission lines to alleviate the degradation of quality factor and phase noise. 8 In addition to the ability to operate at high frequencies 9,10 and generate multiple phase signals, the RTWO can also provide a clock distribution with low jitter and low skew 11 and sustain a traveling wave with low phase noise. 12 Due to these advantages, RTWO has attracted enormous interest in recent years, which has increased the necessity of analysis for different fields of the RTWO.…”

“…For example, the wireless standards need signals with less than 5 phase error. 8 Two different sources that incur phase errors in the RTWO are (a) asymmetry along the transmission line (the resonator mismatch) and (b) inequality of negative transconductors (ÀG m cells) caused by the mismatch among -G m cells transistors and tail currents. The careful layout and the accurate design can decrease some of these mismatches.…”

“…Therefore, the circuit design details for phase error compensation do not consider in Abbasalizadeh and Miar-Naimi. 8 The rest of the paper is organized as follows. Section 2 reviews the basics of the RTWO.…”