scholarly journals Design of Gigahertz Tuning Range 5 GHz LC Digitally Controlled Oscillator in 0.18 μm CMOS

2016 ◽  
Vol 67 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Marijan Jurgo ◽  
Romualdas Navickas
Keyword(s):  
Tuning Range ◽  
Frequency Tuning ◽  
Frequency Divider ◽  
Fine Tuning ◽  
Voltage Source ◽  
Switched Capacitor ◽  
Digitally Controlled ◽  
Digitally Controlled Oscillator ◽  
5 Ghz ◽  
Capacitor Arrays

Abstract In this paper design and simulation of a 4.3 - 5.4 GHz LC digitally controlled oscillator (LC DCO) in IBM 7RF 0.18 μm CMOS technology are presented. Wide gigahertz tuning range is achieved by using two LC DCOs, sharing same structure. DCO is made of one NMOS negative impedance transistor pair and LC tank, which consists of high quality inductor and two switched capacitor arrays for coarse and fine frequency tuning. Coarse and fine tuning switched capacitor arrays are controlled using 6-bit and 3-bit binary words. To increase available frequency values, frequency divider is used. Structure of frequency divider is based on extended-true-single-phase-clock flip-flops. Divider is made of eight divide-by-2 cells connected in daisy chain, thus division values from 2 to 256 are available. Wide tuning range and high division values allows using such DCO with frequency divider in multi-standart transceivers. Whole device is supplied from a single 1.8 V voltage source. At highest frequency proposed device draws 90 mA current including all buffers. Phase noise is −116.4 dBc/Hz at 1 MHz offset from 5.44 GHz carrier. Designed dual DCO and frequency divider occupies about 0.4mm×0.5mm of chip space and whole chip, including pads, occupies 1.5mm × 1.5mm area of silicon.

scholarly journals A 3.22–5.45 GHz and 199 dBc/Hz FoMT CMOS Complementary Class-C DCO

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Lei Ma ◽  
Na Yan ◽  
Sizheng Chen ◽  
Yangzi Liu ◽  
Hao Min
Keyword(s):  
Power Consumption ◽  
Tuning Range ◽  
Frequency Tuning ◽  
Frequency Resolution ◽  
Corner Frequency ◽  
Cmos Process ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Class C ◽  
Digitally Controlled Oscillator

This paper implements a complementary Class-C digitally controlled oscillator (DCO) with differential transistor pairs. The transistors are dynamically biased by feedback loops separately benefiting the robust oscillation start-up with low power consumption. By optimizing three switched capacitor arrays and employing fractional capacitor array with sigma-delta modulator (SDM), the presented DCO operates from 3.22 GHz to 5.45 GHz with a 51.5% frequency tuning range and 0.1 ppm frequency resolution. The design was implemented in a 65 nm CMOS process with power consumption of 2.8 mA at 1.2 V voltage supply. Measurement results show that the phase noise is about −126 dBc/Hz at 3 MHz offset from a 5.054 GHz carrier frequency with the 1/f3 corner frequency of 260 KHz. The resulting FoMT achieves 199.4 dBc/Hz and varies less than 2 dB across the frequency tuning range.

scholarly journals A Design of Wide-Range and Low Phase Noise Linear Transconductance VCO with 193.76 dBc/Hz FoMT for mm-Wave 5G Transceivers

Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 935 ◽  
Author(s):  
Arash Hejazi ◽  
YoungGun Pu ◽  
Kang-Yoon Lee
Keyword(s):  
Phase Noise ◽  
Carrier Frequency ◽  
Tuning Range ◽  
Frequency Tuning ◽  
Cmos Process ◽  
Switched Capacitor ◽  
Voltage Controlled Oscillator ◽  
Wide Range ◽  
Layout Area ◽  
Low Phase Noise

This paper presents a wide-range and low phase noise mm-Wave Voltage Controlled Oscillator (VCO) based on the transconductance linearization technique. The proposed technique eliminates the deep triode region of the active part of the VCO, and lowers the noise introduced by the gm-cell. The switch sizes inside the switched capacitor bank of the VCO are optimized to minimize the resistance of the switches while keeping the wide tuning range. A new layout technique shortens the routing of the VCO outputs, and lowers the parasitic inductance and resistance of the VCO routing. The presented method prevents the reduction of the quality factor of the tank due to the long routing. The proposed VCO achieves a discrete frequency tuning range, of 14 GHz to 18 GHz, through a linear coarse and middle switched capacitor array, and offers superior phase noise performance compared to recent state-of-the-art VCO architectures. The design is implemented in a 45 nm CMOS process and occupies a layout area (including output buffers) of 0.14 mm2. The power consumption of the VCO core is 24 mW from the power supply of 0.8 V. The post-layout simulation result shows the VCO achieves the phase noise performances of −87.2 dBc/Hz and −113 dBc/Hz, at 100 kHz and 1 MHz offset frequencies from the carrier frequency of 14 GHz, respectively. In an 18 GHz carrier frequency, the results are −87.4 dBc/Hz and −110 dBc/Hz, accordingly.

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