Design and measurement of class EF2 power oscillator

• Published in: Electronics letters 2015-05, Vol.51 (10), p.744-745
• Main Authors: Madureira, H, Deltimple, N, Kerherve, E, Dematos, M, Haddad, S
• Format: Article
• Language: English
• Subjects: breakdown voltage; Circuits; Circuits and systems; class EF2 power circuit; class EF2 power oscillator; CMOS; CMOS analogue integrated circuits; electric breakdown; Electric potential; Engineering Sciences; feedback amplifiers; feedback path; frequency 150 MHz; frequency 2.5 GHz; integrated circuit noise; Micro and nanotechnologies; Microelectronics; MOS capacitors; MOS varactor; Oscillators; passive element; passive networks; phase noise; power amplifier; power integrated circuits; power MOSFET; Radio frequencies; RF frequency; size 130 nm; standard CMOS technology; transistor; Tuning; UHF integrated circuits; UHF oscillators; UHF power amplifiers; varactors; Voltage; voltage 2.5 V; voltage stress reduction
• ISSN: 0013-5194; 1350-911X; 1350-911X
• DOI: 10.1049/el.2014.4295

A class EF2 power oscillator designed in standard 130 nm CMOS at 2.5 GHz frequency is presented. The oscillator relies on a direct path based on a power amplifier and a feedback path based on passive elements and an MOS varactor. Class EF2 is used to reduce voltage stress across the switch, enabling a higher output power for modern transistors with low breakdown voltage. The measurement on a class EF2 power oscillator at radio frequency (RF) is presented for the first time. The circuit achieves 17.65 dBm output power from a 2.5 V supply voltage with 27.1% DC-RF efficiency and presents a 150 MHz tuning range. The measured phase noise is −101.6 dBc/Hz at 1 MHz offset. The circuit was implemented in standard 130 nm CMOS technology and consumed a total area of 1.95 mm2. To the authors' knowledge this class EF2 power circuit has never been presented either at RF frequencies or in an integrated technology.