Francesco Cannone

A 2-GS/s 0.35μm SiGe track-and-hold amplifier with 7-GHz analog bandwidth using a novel input buffer

In this paper a Track-and-Hold amplifier (THA), designed in a low cost 0.35μm SiGe 60GHz technology, suitable for SDR applications, is presented. With the implementation of a novel input buffer, the circuit shows a 3dB bandwidth of 7GHz and a distortion better than 50dB up to, about, that frequency during Track phase. Simulations show a THD better than 50dB up to a frequency of 5.77GHz at 2GS/s and a “reconstructed” 3dB full power bandwidth (FPBW) of 5.86GHz. The circuit draws about 220mA from 3.3V supply, considering all the sampling stage, the output buffer and clock driver.

A 2.5-GS/s 62dB THD SiGe Track-and-Hold Amplifier with feedthrough cancellation technique

In this paper a Track-and-Hold Amplifier (THA), designed in a low cost 0.35μm SiGe 60GHz technology is presented. Thanks to the joint action of a novel input buffer and a suppression feedthrough architecture, it is able to guarantee 62dB Total Harmonic Distortion(THD) up to a frequency of 2.2GHz with 0.9Vp-p differential input at a sampling rate (Fs) of 2.5GS/s. The THA core draws about 145mA from 3.5V supply.

New wideband Distributed Voltage Controlled Oscillator with a coarse-fine tuning

The modern telecommunication services require increasingly wide tuning bands and improved spectral purity in order to support the growing demand for high data rate in the new generation wireless standards. The resulting VCOs have to deal with a difficult trade-off between wide tuning bandwidth and phase-noise. The paper introduces a new VCO architecture with a double tuning control, the former coarse to select the band the latter fine to precisely tune the frequency. The VCO is organized in an innovative distributed arrangement. Experimental results validating the theory are reported and discussed

A high bandwidth 11-bit 1.5GS/s track and hold amplifier in 0.25 µm SiGe BiCMOS

The paper describes a Track and Hold Amplifier suitable for high-speed and high resolution applications like Software Defined Radios. Thanks to the adopted techniques to maximize the resolution without reducing the sampling frequency, all the non idealities limiting the equivalent number of bits have been taken into account. In particular a novel technique to reduce the third harmonic distortion has been proposed and exploited. Post-layout simulations show that the performances are quite constant and the linearity is compatible with 11-bit (SFDR) at Fs= 1.5GS/s up to a frequency 1GHz.

A 11-bit Track and Hold Amplifier in 0.25 µm SiGe BiCMOS for RF sampling receivers

The paper describes a Track and Hold Amplifier (THA) suitable for RF sampling and Software Defined Radio receivers where high speed and high resolution are required. The reported THA is based on two main techniques: one for minimizing the differential droop rate and one for improving the HD3 in track mode. Measurements results show that the adopted solutions are both effective. In the desired input band around 1GHz, at the desired sub-sampling frequency (0.5GS/s) the THA provides a linearity compatible with 12-bit (Spurious Free Dynamic Range, SFDR). Moreover at the maximum achievable sampling frequency (1.5GS/s) the performances are quite constant and the resolution is compatible with 11-bit (SFDR) up to an input frequency of 1GHz.

A study on the phase errors distributions in phased array systems based on a behavioural model of radiation-pattern characteristics

A study on the impact of the phase errors distribution on the performances of the phased array systems has been produced using a complete and behavioral model for radiation-pattern characteristics . The study has shown how the phase errors distribution actually affects the performances demonstrating that the rms phase error is a valuable figure of merit of phased array systems but it is not sufficient to completely describe the behavior of a real system. The used model has many input parameters and it has a lot of features, such as parameter simulations with results analysis, unconventional two-dimensional color graph representation capability in order to show more clearly the results. The results of the study demonstrating the previous considerations have been reported.

Complete time-domain behavioral model of Sample-and-Hold Amplifier using SIMULINK ®

The paper describes a SIMULINKreg model for the complete time-domain behavioral simulation of Sample-and-hold Amplifier (SHA). To this purpose, the parameters which affect the operations of a basic SHA blocks are investigated and the non-ideal parameters of these blocks are modeled by using SIMULINKreg. The black-box description achieved gives the advantage that parameter extraction can be done starting from data sheet parameters without interesting the internal circuital structure of the composing blocks. An example using a sinusoidal test signal is reported in order to test the proposed model.

High Precision Digital Based 3.8GHz Phase Shifter

The paper reports a highly repeatable 10-bits 3.8 GHz phase shifter implemented in a standard 0.35 μm SiGe technology for high precision applications. The prototype principle of operations and design are thoroughly described and demonstrated. The generated 0.35° phase step exhibits a rms error lower than 0.32°, mainly determined by the PLL inserted in the architecture.

A location system for indoor at 24 GHz with submillimeter precision

In this paper a new high resolution GPS-based system for indoor is presented. The common systems used for this purpose are not very accurate and usually expensive. The proposed approach allows to obtain systems which are both very accurate and low cost. It is based on the wideband spread spectrum technique at 24 GHz, and achieves an accuracy better than 0.5 millimeter even when the target is moving. The peculiarity of this positioning system compared to others is the fully analog correlation which improves the cost-effectiveness of the system.

A 94dB 1.6GHz SiGe fully differential operational amplifier using a novel class AB output stage

The paper presents a wideband fully differential operational amplifier in 0.35µm SiGe technology. The circuit provides a gain of 94dB and a 1.6GHz unity gain bandwidth drawing 25 mA from 3.3V supply voltage. The circuit employs a novel class AB output stage and it was used to generate wideband low impedance voltage references for a high speed A/D converter.