J. Graffeuil

Low-frequency noise properties of SiGe HBT's and application to ultra-low phase-noise oscillators

This paper presents an extensive electrical characterization of Si/SiGe/Si heterojunction bipolar transistors (HBTs) grown by molecular beam epitaxy (MBE). These devices are designed for microwave and millimeter-wave applications since they present a maximum oscillation frequency in the 40-GHz range. The processing technology, featuring a high-quality oxide passivation, results in ideal Gummel plots and an input noise corner frequency of 250 Hz at lowest. A dielectric resonator oscillator (DRO) at 4.7 GHz has, therefore, been realized. The measured phase-noise level of this oscillator is below -135 dBc/Hz at 10-kHz offset frequency, which is at least 10 dB better than the best FET or HBT state-of-the-art DROs.

Nonlinear modeling and design of bipolar transistors ultra-low phase-noise dielectric-resonator oscillators

This paper presents a design methodology for low phase-noise dielectric-resonator oscillators (DROs) with applications examples at 4 GHz. Different oscillators topologies are investigated and, finally, three oscillators configurations have been simulated, realized in discrete elements, and characterized. The best measured phase-noise magnitude is -133 dBc/Hz at 10-kHz offset frequency.

Design and realization of high Q millimeter-wave structures through micromachining techniques

This paper deals with an original design and realization of high performance micromachined millimeter wave passive circuit on silicon. An appropriate coupling between two coplanar micromachined lines and a dielectric resonator acting on its whispering gallery modes have allowed a loaded quality factor ranging from 500 to 2400 at 35 GHz and leading to a Micromachined Dielectric Resonator Oscillator (MDRO) realization. From finite element 2D simulations, we have obtained unloaded quality factor of 2040 at 77 GHz and 95 GHz using an original micromachined silicon dielectric resonator.

Low Frequency Noise Properties of Microwave Transistors and their Application to Circuit Design

A knowledge of low frequency (L.F) noise in FETs, HBTs and others related devices is essential in designing oscillators, multipliers, mixers and broadband amplifiers. Physical origins and assessment techniques ofthis noise are addressed A lot of L.F noise measurements on commercial and research devices either performed in our laboratory or picked up from literature are presented and are intended to give the state of the art of today available performance. Finally design rules for reducing the impact of L.F noise on microwave circuits are suggested.

Original MEMS-Based Single Pole Double Throw topology for millimeter wave space communications

This paper presents the design, fabrication and characterization of a MEMS-Based Single Pole Double Throw (SPDT) circuit for millimeterwave applications. High performances are achieved thanks to an original circuit design based on MEMS synthesized quarter wave line combined with surface and bulk micromachinings of silicon. 0.6 dB insertion loss of the SPDT circuit was measured with an isolation of 21dB at 30GHz.

Evaluation of two non-standard techniques for the phase noise characterization at microwave frequencies

Two different phase noise measurement techniques dedicated to the test of microwave free running oscillators are described and compared. The interest of an injection locking technique for the characterization of the close to carrier performance of low phase noise DROs is shown through different measurements examples on state-of-the-art DRO at C and X band.

High quality factor and high self-resonant frequency monolithic inductor for millimeter-wave Si-based IC's

Substrate losses of inductors realized with a SiGe BICMOS technology (psubstrate=15 /spl Omega/cm) are investigated. The benefit of introducing a thin conductive (p=0.5 /spl Omega/cm) epitaxial layer below the oxide beneath metal strip in order to obtain a high quality factor and a high self-resonant frequency (SRF) is demonstrated. Finally, measurements of the newly developed inductor show a high quality factor of 22 at 30 GHz with the conductive epitaxial layer connected to ground. Moreover, an impressive measured SRF of 64 GHz is achieved for an inductor value of 0.75 nH.

Ultra low phase noise C and X band bipolar transistors dielectric resonator oscillators

In this paper, a comparison between Si BJT and SiGe HBT devices for ultra low phase noise dielectric resonator microwave oscillators design at 4.7 GHz and 10.2 GHz is presented. Different oscillators topologies have been realized and characterized. The best measured phase noise have been achieved with the SiGe HBT devices. At C band, the best phase noise level is below -135 dBc/Hz at 10 kHz offset frequency and, at X band a value of -118 dBc/Hz at 10 kHz offset frequency has been observed.

Microwave noise parameters of pseudomorphic GaInAs HEMTs under optical illumination

The microwave behavior of pseudomorphic high electron-mobility transistors (pHEMTs) under optical illumination is investigated in this paper. The influence of light on the small-signal equivalent circuit is derived from scattering-parameter measurements. The evolution of the noise parameters versus gate-to-source voltage and their sensibility to illumination is also demonstrated.

Low-frequency noise behavior of InP-based HEMTs and its connection with phase noise of microwave oscillators

This paper deals with the investigation of the low-frequency (LF) noise properties of InP based HEMTs. We have found that a significant part of noise originates from the sample free surface and can be minimized by an appropriate silicon nitride passivation layer. Additional measurements suggest that 1/f noise and Lorentzian noise is generated in the AlInAs donor layer of the devices. A comparative study shows that our devices compare well with the state of the art of HEMTs devices in term of excess noise. In order to investigate the correlation between phase noise and LF noise, both residual and oscillator phase noise measurements were carried out. The obtained results compare well with the state of the art in terms of residual and phase noise performance.