A-193 (dBc/Hz) FoM and −126 (dBc/Hz) phase noise octagonal ring oscillator using pulse injection technique

Abstract

This manuscript presents the design of a low phase noise, high figure of merit (FoM) single-ended octagonal ring oscillator (RO). The proposed RO employs the pulse injection (PI) technique for performance enhancement. The PI technique is used for suppression of phase noise and spurious harmonics. Besides, a novel voltage dependent phase shifter is employed. The proposed RO has an output signal with voltage controlled phase. Different output signal phases can be obtained employing different selected voltages to control the output signal phase. The proposed injection locked ring oscillator (ILRO) represents a suitable implementation for phase shift keying. The proposed ILRO has a measured oscillation frequency of 4.9 GHz with a fine tuning range of 500 MHz. It has a measured phase noise of 2126.17 dBc/Hz @ 1MHz offset while consuming only 4.8 mW of DC power. The proposed ILRO has a FoM of 2193.17 dBc/Hz. This RO has been designed and implemented in 0.18 mm CMOS technology.

A High FoM and Low Phase Noise Edge-Injection-Based Ring Oscillator in 350 nm CMOS for Sub-GHz ADPLL Applications

“…Complementary Metal-Oxide-Semiconductor (CMOS) technology's rapid scaling is promoting all-digital and inductorless radio frequency (RF) blocks to replace their counterparts for improved performance, lower power consumption, and smaller die area. Thus, they attract the interest of nowadays analog and RF designers [1][2][3]. All digital phase locked loop (ADPLL) replaces the voltage controlled oscillator (VCO) by a digitally controlled oscillator (DCO) to digitally generate the controlled clock [1][2][3].…”

“…Thus, they attract the interest of nowadays analog and RF designers [1][2][3]. All digital phase locked loop (ADPLL) replaces the voltage controlled oscillator (VCO) by a digitally controlled oscillator (DCO) to digitally generate the controlled clock [1][2][3]. To enhance the ADPLL noise and jitter performance, a band-bang ADPLL with LC DCO which dissipates larger power and occupies a wider area was presented [1].…”

“…The LC oscillator achieves higher clock frequency and lesser phase noise; however, its area is relatively large, and it consumes a larger amount of power [1]. DCO consumes lower power, occupies smaller die area, and provides a wider tunable range of frequency [1][2][3]. But its phase noise is not as good as LC oscillators phase noise [1][2][3].…”

“…DCO consumes lower power, occupies smaller die area, and provides a wider tunable range of frequency [1][2][3]. But its phase noise is not as good as LC oscillators phase noise [1][2][3].…”

“…Injection locking is being used for ring oscillators' phase noise suppression while dissipating lower power [3]. Sub-harmonic injection resets the injection locked ring oscillators (ILROs) periodically and minimizes their root mean square (RMS) jitter [2,3].…”