MODELING OF NOISE BEHAVIOR OF GRADED BAND GAP CHANNEL MOSFET AT GHz FREQUENCIES

2007 ◽  
Vol 07 (04) ◽  
pp. L507-L517
Author(s):  
ALI ABOU-ELNOUR ◽  
OSSAMA ABO-ELNOR ◽  
HAMDY ABDELHAMEED ◽  
ADEL EL-HENAWY

A novel graded band gap channel Si - SiGe MOSFET structure has been suggested and its characteristics have been investigated. The investigations indicated that the suggested structure reduces the short-channel effects, increases the cut-off frequency, and hence makes its usage at high frequency and Low noise applications possible. To show the superior performance of the suggested structure at GHz frequencies, and as an example, the noise behavior of the structure is determined. First the device noise model parameters are calculated from D.C. and A.C. characteristics. The extracted noise model parameters are then used to determine the minimum noise figure at GHz frequencies. The effects of the different device parameters on the noise performance are determined. Finally, the results are compared with those of conventional MOSFET structure to show the superior performance of graded band gap Si - SiGe MOSFETs at high frequency ranges.

2005 ◽  
Vol 40 (3) ◽  
pp. 726-735 ◽  
Author(s):  
Kwangseok Han ◽  
J. Gil ◽  
Seong-Sik Song ◽  
Jeonghu Han ◽  
Hyungcheol Shin ◽  
...  

Author(s):  
Umesh.P. Gomes ◽  
Mr. Kuldeep ◽  
S. Rathi ◽  
Dhrubes Biswas

A review is presented on the advances in InAlAs/InGaAs High Electron Mobility transistors (HEMT) on silicon substrates for high frequency and low noise applications. Although InAlAs/InGaAs HEMTs on InP and GaAs substrates have been much appreciated due to their superior performance, their widespread applications have been hindered due to higher cost of the substrates. Silicon has been used as an alternative substrate considering the benefits of low cost, technological maturity and integration of III-V and silicon technology inspite of the constraints like lattice mismatch and large difference in thermal expansion coefficient.


2014 ◽  
Vol 23 (05) ◽  
pp. 1450058
Author(s):  
S. MANJULA ◽  
D. SELVATHI

Low noise amplifier (LNA) is an important component in RF receiver front end. An inductively degenerated cascode low noise amplifier (IDCLNA) is mostly preferred for producing good trade-offs such as high gain, low noise figure (NF), high reverse isolation and low power consumption for narrowband applications. This IDCLNA structure is also used to reduce the gate induced noise on the noise performance by inserting the capacitance in parallel with the gate-to-source capacitance of main transistor. Usually, the parasitic overlap capacitances can impose serious constraints on achievable performance and is taken into account in IDCLNA. In this paper, IDCLNA is designed at a frequency of 2.4 GHz with analyzing the impact of parasitic overlap capacitances on IDCLNA in terms of unity current gain frequency (f T ) which will affect the NF of IDCLNA and simulated using 130 nm, 90 nm and 65 nm CMOS technologies. The NF of IDCLNA with and without parasitic overlap capacitances are analyzed and compared for different short channel CMOS processes. Simulation results show that the parasitic overlap capacitances have advantageous to reduce the gate induced noise in IDCLNA for 130-nm CMOS process for 2.4 GHz applications.


1995 ◽  
Vol 06 (01) ◽  
pp. 211-236 ◽  
Author(s):  
R.J. TREW ◽  
M.W. SHIN

Electronic and optical devices fabricated from wide band gap semiconductors have many properties ideal for high temperature, high frequency, high power, and radiation hard applications. Progress in wide band gap semiconductor materials growth has been impressive and high quality epitaxial layers are becoming available. Useful devices, particularly those fabricated from SiC, are rapidly approaching the commercialization stage. In particular, MESFETs (MEtal Semiconductor Field-Effect Transistors) fabricated from wide band gap semiconductors have the potential to be useful in microwave power amplifier and oscillator applications. In this work the microwave performance of MESFETs fabricated from SiC, GaN and semiconducting diamond is investigated with a theoretical simulator and the results compared to experimental measurements. Excellent agreement between the simulated and measured data is obtained. It is demonstrated that microwave power amplifiers fabricated from these semiconductors offer superior performance, particularly at elevated temperatures compared to similar components fabricated from the commonly employed GaAs MESFETs.


1985 ◽  
Vol 46 (6) ◽  
pp. 600-602 ◽  
Author(s):  
R. J. Malik ◽  
F. Capasso ◽  
R. A. Stall ◽  
R. A. Kiehl ◽  
R. W. Ryan ◽  
...  

Author(s):  
Z. A. Djennati ◽  
K. Ghaffour

In this paper, a noise revision of an InAlAs/InGaAs/InP psoeudomorphic high electron mobility transistor (pHEMT) in presented. The noise performances of the device were predicted over a range of frequencies from 1GHz to 100GHz. The minimum noise figure (NFmin), the noise resistance (Rn) and optimum source impedance (Zopt) were extracted using two approaches. A physical model that includes diffusion noise and G-R noise models and an analytical model based on an improved PRC noise model that considers the feedback capacitance Cgd. The two approaches presented matched results allowing a good prediction of the noise behaviour. The pHEMT was used to design a single stage S-band low noise amplifier (LNA). The LNA demonstrated a gain of 12.6dB with a return loss coefficient of 2.6dB at the input and greater than -7dB in the output and an overall noise figure less than 1dB.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Cyrille Gardès ◽  
Sonia Bagumako ◽  
Ludovic Desplanque ◽  
Nicolas Wichmann ◽  
Sylvain Bollaert ◽  
...  

We report on high frequency (HF) and noise performances of AlSb/InAs high electron mobility transistor (HEMT) with 100 nm gate length at room temperature in low-power regime. Extrinsic cut-off frequenciesfT/fmaxof 100/125 GHz together with minimum noise figureNFmin=0.5 dB and associated gainGass=12 dB at 12 GHz have been obtained at drain bias of only 80 mV, corresponding to 4 mW/mm DC power dissipation. This demonstrates the great ability of AlSb/InAs HEMT for high-frequency operation combined with low-noise performances in ultra-low-power regime.


2009 ◽  
Vol 102 (4) ◽  
pp. 2342-2357 ◽  
Author(s):  
William C. Stacey ◽  
Maciej T. Lazarewicz ◽  
Brian Litt

There is great interest in the role of coherent oscillations in the brain. In some cases, high-frequency oscillations (HFOs) are integral to normal brain function, whereas at other times they are implicated as markers of epileptic tissue. Mechanisms underlying HFO generation, especially in abnormal tissue, are not well understood. Using a physiological computer model of hippocampus, we investigate random synaptic activity (noise) as a potential initiator of HFOs. We explore parameters necessary to produce these oscillations and quantify the response using the tools of stochastic resonance (SR) and coherence resonance (CR). As predicted by SR, when noise was added to the network the model was able to detect a subthreshold periodic signal. Addition of basket cell interneurons produced two novel SR effects: 1) improved signal detection at low noise levels and 2) formation of coherent oscillations at high noise that were entrained to harmonics of the signal frequency. The periodic signal was then removed to study oscillations generated only by noise. The combined effects of network coupling and synaptic noise produced coherent, periodic oscillations within the network, an example of CR. Our results show that, under normal coupling conditions, synaptic noise was able to produce gamma (30–100 Hz) frequency oscillations. Synaptic noise generated HFOs in the ripple range (100–200 Hz) when the network had parameters similar to pathological findings in epilepsy: increased gap junctions or recurrent synaptic connections, loss of inhibitory interneurons such as basket cells, and increased synaptic noise. The model parameters that generated these effects are comparable with published experimental data. We propose that increased synaptic noise and physiological coupling mechanisms are sufficient to generate gamma oscillations and that pathologic changes in noise and coupling similar to those in epilepsy can produce abnormal ripples.


Author(s):  
Abu Bakar Ibrahim ◽  
Che Zalina Zulkifli ◽  
Shamsul Arrieya Ariffin ◽  
Nurul Husna Kahar

The low noise amplifier (LNA) circuit is exceptionally imperative as it promotes and initializes general execution performance and quality of the mobile communication system. LNA's design in radio frequency (R.F.) circuit requires the trade-off numerous imperative features' including gain, noise figure (N.F.), bandwidth, stability, sensitivity, power consumption, and complexity. Improvements to the LNA's overall performance should be made to fulfil the worldwide interoperability for microwave access (WiMAX) specifications' prerequisites. The development of front-end receiver, particularly the LNA, is genuinely pivotal for long-distance communications up to 50 km for a particular system with particular requirements. The LNA architecture has recently been designed to concentrate on a single transistor, cascode, or cascade constrained in gain, bandwidth, and noise figure.


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