scholarly journals Comparative Analysis of CNTFET Models through the Design of a Differential Amplifier

Author(s):  
Gennaro Gelao ◽  
◽  
Roberto Marani ◽  
Anna Gina Perri

In this paper we compare simulation results on a differential pair circuit using a CNTFET model, already proposed by us, with the result obtained using Stanford model. We study the case of differential pair with differential input and single ended output as core of a 50 GHz amplifier for mm waves band. We consider the case of a CNTFET having a single CNT tube with indices (19,0) and 25 nm long. For this circuit we present result for its main parameters: gain, input impedance, output impedance, noise and distortion. Since the Stanford model includes fixed capacitance, for comparison we applied the same capacitance on our model. Since this capacitances dominate the high frequency cut, results are not much different, except for the lack of noise modelling in the Stanford model.

2003 ◽  
Vol 26 (3) ◽  
pp. 167-170 ◽  
Author(s):  
R. Saraswat ◽  
K. Pal ◽  
S. Rana

Three circuits each realizing second-order all-pass/notch filter transfer functions are reported. All circuits use grounded capacitors and are suitable for IC implementation. These circuits offer the advantages of high input impedance and low output impedance and are superior to all earlier realisations.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
J. K. Pathak ◽  
A. K. Singh ◽  
Raj Senani

Two new configurations for voltage mode universal filters (VMUFs) using only two current differencing buffered amplifiers (CDBAs) are proposed. Both of the new configurations can realize all the five standard types of the filters, namely, low pass (LP), high pass (HP), band pass (BP), band stop (BS), and all pass (AP), from the same topology. In contrast to previously known CDBA-based VMUFs, the new configurations do not need an additional active device for voltage inversion to realize all pass functions. The proposed configurations offer the tunability of the natural angular frequency (ωo), quality factor (Q), or the bandwidth (BW) through separate virtually grounded resistors. Moreover, both circuits have resistive input impedance (which can be made high) and a low output impedance to facilitate easy cascading without additional buffers. PSPICE simulation results, based upon commercially available AD844 ICs to implement the CDBA, are included which confirm the practical workability of the new VMUF configurations.


Author(s):  
E. Faghand ◽  
S. Karimian ◽  
E. Mehrshahi ◽  
N. Karimian

Abstract A new simple computational tool is proposed for the synthesis of multi-section coupled-line filters based on combined modified planar circuit method (MPCM) and transmission line method (TLM) analysis, referred to as MPCM-TLM. Due to its fundamentally simple architecture, the presented tool offers significantly faster optimization of coupled-line filters – for exactly the same initial simulation set-up – than other costly commercially-available tools, giving equally reliable results. Validity and accuracy of the proposed tool have been verified through the design of 3rd, 5th, and 7th order coupled-line filters and comparative analysis between results obtained from the proposed approach and the high-frequency structure simulator. A remarkable 99% time reduction in the analysis is recorded in the case of 7th order filter using the proposed tool, for almost identical results to HFSS. Therefore, it can be confidently claimed that the proposed technique can be used as a reliable alternative to existing complex, costly, processor-intensive CAD tools.


Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1212
Author(s):  
Kazuma Koketsu ◽  
Toru Tanzawa

This paper describes a charge pump system for a flexible thermoelectric generator (TEG). Even though the TEG has high-output impedance, the system controls the input voltage to keep it higher than the minimum operating voltage by modulating the input impedance of the charge pump using two-phase operation with low- and high-input impedance modes. The average input impedance can be matched with the output impedance of the TEG. How the system can be designed is also described in detail. A design demonstration was performed for the TEG with 400 Ω. The fabricated system was also measured with a flexible-type TEG based on carbon nanotubes. Even with an output impedance of 1.4 kΩ, the system converted thermal energy into electric power of 30 μW at 2.5 V to the following sensor ICs.


2010 ◽  
Vol 19 (03) ◽  
pp. 519-528 ◽  
Author(s):  
M. PRAMOD ◽  
T. LAXMINIDHI

Continuous common mode feedback (CMFB) circuits having high input impedance and low distortion are proposed. The proposed circuits are characterized for 0.18 μm CMOS process with 1.8 V supply. Simulation results indicate that the proposed common mode detector consumes no standby power and CMFB circuit consumes 27–34% less power than previous high swing CMFB circuits.


Frequenz ◽  
2018 ◽  
Vol 72 (5-6) ◽  
pp. 197-208 ◽  
Author(s):  
Pramod Kumar ◽  
Santanu Dwari ◽  
Shailendra Singh ◽  
Ashok Kumar ◽  
N. K. Agrawal ◽  
...  

AbstractIn this paper various shapes of DR antennas excited by common feed have been proposed and successfully implemented for wideband applications. Proposed structures are Hemispherical, Arrow-shaped and Triangular DRA, while common excited feed is inverted trapezoidal conformal patch. These shapes of DR offer significant optimization in several parameters such as impedance bandwidth, peak gain and bandwidth per unit volume of the antenna. By using inverted trapezoidal patch feed mechanism an impedance bandwidth (VSWR<2) of about 63 % for hemispherical shape, 66 % for arrow shape, and 72 % for triangular shape DRA has been achieved with maximum bandwidth per unit volume. Proposed wideband DRAs i. e. triangular, hemispherical, and arrow shapes of DR antennas cover almost complete C-band (4 GHz–8 GHz) frequency spectrum of microwave. The average peak gain within the operating band for hemispherical, arrow, and triangular shape DRA are about 5, 5.4, and 5.5 dB respectively. A comparative analysis of proposed structures for various antenna parameters has been analyzed by HFSS (High-Frequency Structure Simulator) and validated by experimental results.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Sudhanshu Maheshwari ◽  
Bhartendu Chaturvedi

This paper presents some additional high input low output impedance analog networks realized using a recently introduced single Dual-X Current Conveyor with buffered output. The new circuits encompass several all-pass sections of first- and second-order. The voltage-mode proposals benefit from high input impedance and low output impedance. Nonideality and sensitivity analysis is also performed. The circuit performances are depicted through PSPICE simulations, which show good agreement with theory.


Today in communication field, many antennas have been evolved for various applications. The most popularly used antennas are micro-strip antennas. These antennas can be easily fabricated at reasonably low cost. Hence, these antennas are gaining lot of importance in recent times. Many techniques have been in use for micro strip antennas to improve the performance of the antenna parameters. The design of these antennas is slowly moving towards high frequencies, where there is lot of advantage with bandwidth. In this paper a normal and E shaped inset micro-strip antenna in Ku-Band is simulated and the results are presented. It is noted that CST-MS 2015 tool has been used to get the simulation results.


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