A Low-Voltage CMOS Buffer for RF Applications Based on a Fully-Differential Voltage-Combiner

Part 20: Electronics: RF ApplicationsInternational audienceThis paper presents a new CMOS buffer circuit topology for radio-frequency (RF) applications based on a fully-differential voltage-combiner circuit, capable of operating at low-voltage. The proposed circuit uses a combination of common-source (CS) and common-drain (CD) devices. The simulation results show good levels of linearity and bandwidth. To improve total harmonic distortion (THD) a source degeneration technique is used. The proposed circuit has been designed in a 130nm logic CMOS technology and it achieves a simulated gain of 1.54 dB, a bandwidth of 1.14 GHz for a total power dissipation of 13.34 mW, when driving an RF active probe (with 0.8 pF in parallel with 200 kΩ)

Design of a 4.2-5.4 GHz Differential LC VCO using 0.35 m SiGe BiCMOS Technology

In this paper, a 4.2-5.4 GHz, Gm LC voltage controlled oscillator (VCO) for IEEE 802.11a standard is presented. The circuit is designed with AMS 0.35´m SiGe BiCMOS process that includes high-speed SiGe Heterojunction Bipolar Transistors (HBTs). Phase noise is -110.7 dBc/Hz at 1MHz offset from 5.4 GHz carrier frequency and -113.5 dBc/Hz from 4.2 GHz carrier frequency. A linear, 1200 MHz tuning range is obtained utilizing accumulation-mode varactors. Phase noise is relatively low due to taking the advantage of differential tuning concept. Output power of the fundamental frequency changes between 4.8 dBm and 5.5 dBm depending on the tuning voltage. The circuit draws 2 mA without buffers and 14.5 mA from 2.5 V supply including buffer circuits leading to a total power dissipation of 36.25 mW. The circuit occupies an area of 0.6 mm2 on Si substrate including RF and DC pads

Design of a tunable multi-band differential LC VCO using 0.35 mu m SiGe BiCMOS technology for multi-standard wireless communication systems

In this paper, an integrated 2.2-5.7GHz multi-band differential LC VCO for multi-standard wireless communication systems was designed utilizing 0.35 mu m SiGe BiCMOS technology. The topology, which combines the switching inductors and capacitors together in the same circuit, is a novel approach for wideband VCOs. Based on the post-layout simulation results, the VCO can be tuned using a DC voltage of 0 to 3.3 V for 5 different frequency bands (2.27-2.51 GHz, 2.48-2.78 GHz, 3.22-3.53 GHz, 3.48-3.91 GHz and 4.528-5.7 GHz) with a maximum bandwidth of 1.36 GHz and a minimum bandwidth of 300 MHz. The designed and simulated VCO can generate a differential output power between 0.992 and -6.087 dBm with an average power consumption of 44.21 mW including the buffers. The average second and third harmonics level were obtained as -37.21 and -47.6 dBm, respectively. The phase noise between -110.45 and -122.5 dBc/Hz, that was simulated at 1 MHz offset, can be obtained through the frequency of interest. Additionally, the figure of merit (FOM), that includes all important parameters such as the phase noise, the power consumption and the ratio of the operating frequency to the offset frequency, is between -176.48 and -181.16 and comparable or better than the ones with the other current VCOs. The main advantage of this study in comparison with the other VCOs, is covering 5 frequency bands starting from 2.27 up to 5.76 GHz without FOM and area abandonment. Output power of the fundamental frequency changes between -6.087 and 0.992 dBm, depending on the bias conditions (operating bands). Based on the post-layout simulation results, the core VCO circuit draws a current between 2.4-6.3 mA and between 11.4 and 15.3 mA with the buffer circuit from 3.3 V supply. The circuit occupies an area of 1.477 mm(2) on Si substrate, including DC, digital and RF pads

Design of a 4.2-5.4 GHz differential LC VCO using 0.35 mu m SiGeBiCMOS technology for IEEE 802.11a applications

In this paper, a 4.2-5.4 GHz, -Gm LC voltage controlled oscillator (VCO) for IEEE 802.11a standard is presented. The circuit is designed with AMS 0.35 mu m SiGe BiCMOS process that includes high-speed SiGe Heterojunction Bipolar Transistors (HBTs). According to post-layout simulation results, phase noise is -110.7 dBc/Hz at 1 MHz offset from 5.4 GHz carrier frequency and -113.4 dBc/Hz from 4.2 GHz carrier frequency. A linear, 1200 MHz tuning range is obtained from the simulations, utilizing accumulation-mode varactors. Phase noise was also found to be relatively low because of taking advantage of differential tuning concept. Output power of the fundamental frequency changes between 4.8 dBm and 5.5 dBm depending on the tuning voltage. Based on the simulation results, the circuit draws 2 mA without buffers and 14.5 mA from 2.5 V supply including buffer circuits leading to a total power dissipation of 36.25 mW. The circuit layout occupies an area of 0.6 mm(2) on Si substrate, including DC and RF pads

A 0.18µm CMOS DDCCII for Portable LV-LP Filters

In this paper a current mode very low voltage (LV) (1V) and low power (LP) (21 µW) differential difference second generation current conveyor (CCII) is presented. The circuit is developed by applying the current sensing technique to a fully balanced version of a differential difference amplifier (DDA) so to design a suitable LV LP integrated version of the so-called differential difference CCII (DDCCII). Post-layout results, using a 0.18µm SMIC CMOS technology, have shown good general circuit performances making the proposed circuit suitable for fully integration in battery portable systems as, for examples, fully differential Sallen-Key bandpass filter

A Low Noise Sub-Sampling PLL in Which Divider Noise Is Eliminated and PD-CP Noise Is not multiplied by N^2

This paper presents a 2.2-GHz low jitter sub-sampling based PLL. It uses a phase-detector/charge-pump (PD/CP)that sub-samples the VCO output with the reference clock. In contrast to what happens in a classical PLL, the PD/CP noise is not multiplied by N2 in this sub-sampling PLL, resulting in a low noise contribution from the PD/CP. Moreover, no frequency divider is needed in the locked state and hence divider noise and power can be eliminated. An added frequency locked loop guarantees correct frequency locking without degenerating jitter performance when in lock. The PLL is implemented in a standard 0.18- m CMOS process. It consumes 4.2 mA from a 1.8 V supply and occupies an active area of 0.4 X 0.45 m

A 90 nm CMOS 16 Gb/s Transceiver for Optical Interconnects

Interconnect architectures which leverage high-bandwidth optical channels offer a promising solution to address the increasing chip-to-chip I/O bandwidth demands. This paper describes a dense, high-speed, and low-power CMOS optical interconnect transceiver architecture. Vertical-cavity surface-emitting laser (VCSEL) data rate is extended for a given average current and corresponding reliability level with a four-tap current summing FIR transmitter. A low-voltage integrating and double-sampling optical receiver front-end provides adequate sensitivity in a power efficient manner by avoiding linear high-gain elements common in conventional transimpedance-amplifier (TIA) receivers. Clock recovery is performed with a dual-loop architecture which employs baud-rate phase detection and feedback interpolation to achieve reduced power consumption, while high-precision phase spacing is ensured at both the transmitter and receiver through adjustable delay clock buffers. A prototype chip fabricated in 1 V 90 nm CMOS achieves 16 Gb/s operation while consuming 129 mW and occupying 0.105 mm^2

A digitally controlled threshold adjustment circuit in a 0.13um SiGe BiCMOS technology for receiving multilevel signals up to 80Gbps

In this paper, a high bandwidth digitally controlled threshold adjustment circuit is proposed which can be used for demodulating high-speed multi-level signals. Simulations of the bandwidth are presented together with measurements of the control currents to indicate the threshold adjustment capability. A bandwidth above 80GHz in a 0.13µm SiGe BiCMOS technology and a threshold tunable between ±160mV in steps of 0.6mV is achieved, allowing very precise control of the threshold level. This allows the circuit to accurately position the threshold on the eye-crossing of a high speed multi-level signals. By applying this circuit to demodulate a duobinary signal over a 40GHz channel, a data rate of up to 80Gbps can be achieved