A New Current-Shaping Technique Based on a Feedback Injection Mechanism to Reduce VCO Phase Noise
Inductor-capacitor voltage controlled oscillators (LC-VCOs) are the most common type of oscillator used in sensors systems, such as transceivers for wireless sensor networks (WSNs), VCO-based reading circuits, VCO-based radar sensors, etc. This work presents a technique to reduce the LC-VCOs phase n...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-10-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/21/19/6583 |
| _version_ | 1797515699530235904 |
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| author | Francisco Javier del Pino Suárez Sunil Lalchand Khemchandani |
| author_facet | Francisco Javier del Pino Suárez Sunil Lalchand Khemchandani |
| author_sort | Francisco Javier del Pino Suárez |
| collection | DOAJ |
| description | Inductor-capacitor voltage controlled oscillators (LC-VCOs) are the most common type of oscillator used in sensors systems, such as transceivers for wireless sensor networks (WSNs), VCO-based reading circuits, VCO-based radar sensors, etc. This work presents a technique to reduce the LC-VCOs phase noise using a new current-shaping method based on a feedback injection mechanism with only two additional transistors. This technique consists of keeping the negative resistance seen from LC tank constant throughout the oscillation cycle, achieving a significant phase noise reduction with a very low area increase. To test this method an LC-VCO was designed, fabricated and measured on a wafer using 90 nm CMOS technology with 1.2 V supply voltage. The oscillator outputs were buffered using source followers to provide additional isolation from load variations and to boost the output power. The tank was tuned to 1.8 GHz, comprising two 1.15 nH with 1.5 turns inductors with a quality factor (Q) of 14, a 3.27 pF metal-oxide-metal capacitor, and two varactors. The measured phase noise was −112 dBc/Hz at 1 MHz offset. Including the pads, the chip area is 750 × 850 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>m<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mn>2</mn></msup></semantics></math></inline-formula>. |
| first_indexed | 2024-03-10T06:50:58Z |
| format | Article |
| id | doaj.art-3d7d7d45f4e64283a243d492e20dcaa6 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-10T06:50:58Z |
| publishDate | 2021-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-3d7d7d45f4e64283a243d492e20dcaa62023-11-22T16:48:18ZengMDPI AGSensors1424-82202021-10-012119658310.3390/s21196583A New Current-Shaping Technique Based on a Feedback Injection Mechanism to Reduce VCO Phase NoiseFrancisco Javier del Pino Suárez0Sunil Lalchand Khemchandani1Departamento de Ingeniería Electrónica y Automática, Institute for Applied Microelectronics (IUMA), Universidad de Las Palmas de Gran Canaria, E-35017 Las Palmas de Gran Canaria, SpainDepartamento de Ingeniería Electrónica y Automática, Institute for Applied Microelectronics (IUMA), Universidad de Las Palmas de Gran Canaria, E-35017 Las Palmas de Gran Canaria, SpainInductor-capacitor voltage controlled oscillators (LC-VCOs) are the most common type of oscillator used in sensors systems, such as transceivers for wireless sensor networks (WSNs), VCO-based reading circuits, VCO-based radar sensors, etc. This work presents a technique to reduce the LC-VCOs phase noise using a new current-shaping method based on a feedback injection mechanism with only two additional transistors. This technique consists of keeping the negative resistance seen from LC tank constant throughout the oscillation cycle, achieving a significant phase noise reduction with a very low area increase. To test this method an LC-VCO was designed, fabricated and measured on a wafer using 90 nm CMOS technology with 1.2 V supply voltage. The oscillator outputs were buffered using source followers to provide additional isolation from load variations and to boost the output power. The tank was tuned to 1.8 GHz, comprising two 1.15 nH with 1.5 turns inductors with a quality factor (Q) of 14, a 3.27 pF metal-oxide-metal capacitor, and two varactors. The measured phase noise was −112 dBc/Hz at 1 MHz offset. Including the pads, the chip area is 750 × 850 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>m<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mn>2</mn></msup></semantics></math></inline-formula>.https://www.mdpi.com/1424-8220/21/19/6583LC-VCOCMOSphase noisecurrent-shaping90 nmcurrent tail |
| spellingShingle | Francisco Javier del Pino Suárez Sunil Lalchand Khemchandani A New Current-Shaping Technique Based on a Feedback Injection Mechanism to Reduce VCO Phase Noise Sensors LC-VCO CMOS phase noise current-shaping 90 nm current tail |
| title | A New Current-Shaping Technique Based on a Feedback Injection Mechanism to Reduce VCO Phase Noise |
| title_full | A New Current-Shaping Technique Based on a Feedback Injection Mechanism to Reduce VCO Phase Noise |
| title_fullStr | A New Current-Shaping Technique Based on a Feedback Injection Mechanism to Reduce VCO Phase Noise |
| title_full_unstemmed | A New Current-Shaping Technique Based on a Feedback Injection Mechanism to Reduce VCO Phase Noise |
| title_short | A New Current-Shaping Technique Based on a Feedback Injection Mechanism to Reduce VCO Phase Noise |
| title_sort | new current shaping technique based on a feedback injection mechanism to reduce vco phase noise |
| topic | LC-VCO CMOS phase noise current-shaping 90 nm current tail |
| url | https://www.mdpi.com/1424-8220/21/19/6583 |
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