A 52 GHz Frequency Synthesizer Featuring a 2nd Harmonic Extraction Technique That Preserves VCO Performance

Abstract

This paper introduces a 2nd harmonic extraction technique and its implementation in a 46.4-58.1 GHz frequency synthesizer. The frequency doubling approach is based on tapping second harmonic signals at the VCO supply and tail nodes and amplifying them to provide a differential output. Since the amplifiers do not load the VCO outputs, the proposed technique does not affect either the tuning range or the frequency of the VCO. Moreover, a novel noise bypass technique is utilized to ensure that the amplifiers do not degrade the VCO phase noise. As a result, the frequency synthesizer achieves 22.4% tuning range (46.4-58.1 GHz) and phase noise below -118 dBc/Hz while consuming 66 mW from a 1 V supply. The stacked common gate amplifier can also be utilized for voltage regulation, providing a relatively constant FOM performance over a 2X power dissipation range. The synthesizer occupies 0.6 mm 1 mm in IBM 32 nm SOI CMOS.

A stable U-band VCO in 65 nm CMOS with -0.11 dBm high output power

“…The capacitance of C B1 was greater than that of C B2 , so the tuning range from V CTRL1 was wider than from V CTRL2 . The reason for the narrowness of the operating range compared with previous works was that the capacitance of the VCO was small for fine tuning at the U-band [1][2][3]. The maximum K VCO of the V CTRL1 was 1.52 GHz/V and the maximum K VCO of the V CTRL2 was (a) (b) Fig.…”

“…The Q-factor of the inductor is one of the most important factors to affecting the performance of the VCO [1][2][3][4][5][6][7][8], and is calculated from [Im(Y 11 )/Re(Y 11 )] [8]. Fig.…”

“…VCO is a necessary component when it comes to implementing a single-chip radio in a communication system [1][2][3][4][5][6][7]. However, CMOS VCOs have the limitation of a low quality factor (Q-factor) using on-chip passive components [1][2][3][4][5][6][7][8].…”

“…However, CMOS VCOs have the limitation of a low quality factor (Q-factor) using on-chip passive components [1][2][3][4][5][6][7][8]. Thus, a transformer feedback technique is used to increase the output voltage swing, and the inductor of the LC oscillator based on transmission line theory enhances high frequency performance [2,3,6].…”

“…A high output power results in correct data transfer but deterioration of the phase noise performance. It is difficult to obtain high output power for the VCO operating at the U-band [1][2][3]8]. The VCO gain (K VCO ) is also important factor in the VCO and a low K VCO could improve the phase noise performance [7].…”