Amir Masnadi

Graduate Student
Analog and RF Electronics
System on Chip Laboratory
University of British Columbia, Vancouver, Canada


Research Interest:

   • Fundamental Limits of CMOS Electronics
   • 60GHz to Terahertz Electronics
   • Communication Circuits, Low Power , Low Voltage
   • CDR Systems
   • High Speed Transceiver for Optical Communication
   • Radar System

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I was born in Shiraz, Iran, on august 24th, 1988, I am Graduate student in the Electrical and Computer Engineering Department, University of British Columbia , Canada. I got my BSc. as a first rank student from University of Tehran, Iran. 

A.H Masnadi Shirazi, S.Mirabbasi "An Ultra-Low-Voltage CMOS Mixer Using Switched-Transconductance, Current-Reuse and Dynamic-Threshold-Voltage Gain-Boosting Techniques", Paper Accepted, NEWCAS, 10th IEEE International, 2012,

            Abstract- The scaling of CMOS technologies has a great impact on analog and radio-frequency (RF) circuit design. In particular, as technology advances the available voltage headroom is decreased due to the use of lower supply voltage. In this paper, an architecture for ultra-low-voltage RF CMOS mixers is introduced. The structure uses switched- transconductance technique in conjunction with current-reuse and dynamic-threshold-voltage gain-boosting techniques to reduce the required supply voltage and power consumption while providing a high conversion gain. As a proof-of-concept, a 2.5-GHz down-conversion mixer is designed and laid out in a 0.13-m CMOS process. Post-layout simulation results show that the mixer achieves a conversion gain of 13 dB while consuming 480 W from a 0.35-V supply.


•   H. Rashtian, A.H Masnadi Shirazi, S.Mirabbasi On the Use of  Body-Biasing to Improve Linearity in Gilbert-Cell CMOS Mixers", Paper Submitted, MWSCAS 2012.

            Abstract-this paper presents the application of body-biasing to improve linearity performance of Gilbert-cell CMOS mixers. In order to improve the linearity, the bulk bias voltage of the transistors in the local oscillator (LO) stage is adjusted. Based on post-layout simulation results, this technique results in a 5 dB improvement in the third-order intercept point (IP3) of the mixer. The improvement in linearity is obtained while the conversion gain and power consumption of the mixer remain virtually intact. A 0.13-m CMOS proof-of-concept prototype is implemented which operates at radio frequency (RF) of 2.4 GHz with an intermediate frequency (IF) of 50 MHz and draws 2.25 mA from a 1.2 V supply.


• A.H Masnadi Shirazi, Hooman Rashtian ,S.Mirabbasi A Linearity Enhancement Technique and Its Application to CMOS Wideband Low-Noise Amplifiers  ", ICECS, 2012,

            Abstract-Undesired harmonics have severe impacts on performance of electronic circuits and systems, especially for those used for radio frequency (RF) applications. In this paper, a harmonic cancellation technique based on combining two phase-shifted versions of the signal is introduced. As a proof-of-concept, a wideband (0.07 to 7.5 GHz) low-noise amplifier (LNA) with 3rd-harmonic cancellation technique is designed and laid out in a 0.13-m CMOS process. In this design, phase-shifter circuits are implemented using passive lumped components. Post-layout simulation results show that the LNA achieves a noise figure (NF) of 2.3 dB, S21 of 17.9 dB while consuming 15.6 mW from a 1.2 V supply and significantly cancelling the 3rd harmonic.

Publication :

   • A.H Masnadi Shirazi, "Ab initio Absorption Study of Water and Oxygen Mixture; IR and Millimeter Waves", UBC, 2012, PDF

            Abstract: Optical absorption of water and oxygen molecules plays an important role in total absorption of ambient atmosphere. In this work, first the principle of optical absorption is discussed, and then absorption spectrum of each molecule at different phases (single molecule, liquid and gas) is studied using density function theory, Hartree-Fock and Molecular Dynamics methods. Finally, mixture of oxygen and water with their atmospheric proportions is made and studied. It is found that the oxygen absorption is dominant in the range of 1000-2000 cm-1, while water absorption is governing in vast range of millimeter waves and terahertz (main absorber of sun light). In addition, it is shown that pressure of mixture can change the vibration modes and absorption spectrum respectively.

Useful Software :
ADF: Amsterdam Density Functional software
Our two flagship Density Functional Theory (DFT) programs are powerful computational tools to understand and predict chemical structure, reactivity, and spectroscopy:

•ADF for molecules
•BAND for periodic systems

Our programs run in parallel out-of-the-box on Windows, Mac, and Linux, with an excellent Graphical User Interface. ADF and BAND feature relativistic effects and localized Slater basis sets for the entire periodic table, with a strong track record in tackling challenging chemical problems, in particular:

•structure and reactivity
•chemical analysis
•transition metals and heavy elements
•environment effects (solvents, proteins)

We also offer quick, more approximate methods for studies in chemistry, chemical engineering, and material science:

•DFTB: fast approximate DFT
•MOPAC2009: semi-empirical code
•ReaxFF: reactive force field dynamics
•COSMO-RS: fluid thermodynamics

Our highly trained team of theoretical chemists and physicists continue to expand the scope and functionality of our software and offer full scientific support. Included tools enable QM/MM, ONIOM, adaptive MD, and meta-dynamics.


• A.H Masnadi Shirazi, "Ab initio Study of Hydrogen Molecule", UBC, 2012, PDF , Matlab Code

                In this work Hydrogen molecule is solved by HF method. Matlab code is available

• A.H Masnadi Shirazi, "On Design of CIGS-Metal Solar Cell - Challenges and Optimization", UBC, 2011, PDF

• A.H Masnadi Shirazi, "Design of AlGaInP Orange LED and a study on Dichoromic and Trichromic White LED", UBC, 2011, PDF

A.H Masnadi Shirazi, Parisa Owji, Error Concealment In Image Communication Using Edge Map Watermarking and Spatial Smoothing, Electrical Engineering Department, University of Tehran, 2009.

                  Abstract: We propose a simple and efficient method for reconstructing an image which passed from network tunnel in transmitter and because of AWGN error some of its information missed in receiver. We use edge map, watermarking and estimation to predict what the losses are.

My BSc. Activities , Click Here

A.H Masnadi Shirazi, S.Mirabbasi "An ultra-low-voltage ultra-low-power CMOS active mixer", Journal of Analog Integrated Circuit and Signal Processing, Springer, 2013Link , PDF

            Abstract: The scaling of CMOS technology has greatly influenced the design of analog and radio frequency circuits. In particular, as technology advances, due to the use of lower supply voltage the available voltage headroom is decreased. In this paper, after a brief overview of conventional low-power CMOS active mixer structures, we introduce an active mixer structure with sub-mW-level power consumption that is capable of operating from a supply voltage comparable or lower than the threshold voltage of the transistor. In addition, the proposed architecture provides a performance and conversion gain (CG) that compares favorably or exceeds those of the state-ofthe- art designs. As a proof-of-concept, a wide-band DC to 8.5 GHz down-conversion mixer is designed and fabricated in a 90-nm CMOS process. Measurement results show that the mixer achieves a CG as high as 18 dB while consuming 98 lW from a 0.3-V supply.


A.H Masnadi Shirazi, S.Mirabbasi "A low-power 2.4-GHz combined LNA-VCO structure in 0.13-m CMOS", Journal of Analog Integrated Circuit and Signal Processing, Springer, 2013, Link , PDF

            Abstract: A combined low-noise amplifier and voltage-controlled oscillator (LNA-VCO) is designed and laid-out in a 0.13-m CMOS technology. The low-power LC VCO and LNA circuits are stacked and share the same bias current. An LC filter is used between the LNA and the VCO to improve the phase noise performance of the VCO. Based on post-layout simulations, the LNA achieves a gain of 17.7 dB and a noise figure of 5.1 dB at 2.4 GHz. The VCO has a center frequency of 2.45 GHz with a 370 mV output swing and a phase noise of
-111 dBc/Hz at 1-MHz offset. The LNA-VCO consumes 124 W from a 0.8 V supply.

Recently Submitted Thesis :
Title: On the design of low-voltage power-efficient CMOS active down-conversion mixers
Author: Masnadi Shirazi Nejad, Amir Hossein
Degree: Master of Applied Science - MASc
Program: Electrical and Computer Engineering
Copyright Date: 2013
Publicly Available in cIRcle: 2013-04-12
Click Here for This Thesis

Abstract: The scaling of CMOS technologies has a great impact on analog and radio-frequency (RF) circuit design. In particular, as technology advances the available voltage headroom is decreased due to the use of lower supply voltage. In addition to design challenges due to the headroom limitation, the power consumption is also becoming more important, in particular, in wireless communication applications and portable devices. In this work, we investigate several design techniques for achieving ultra-low-voltage (< 0.5 V), ultra-low-power (< 500 W), and ultra-wideband (DC to 8 GHz) wireless receiver building blocks with a specific focus on the active CMOS mixers. Mixers are important building blocks of almost all modern transceivers and they are primarily used for frequency translation.

In this work, we briefly review many state-of-the-art design techniques, discuss the advantages and drawbacks of currently used methods, and then we introduce design techniques to improve performances of different receiver building blocks, namely, mixers and LNAs. As a proof-of-concept three different RF active CMOS mixers are designed, have been fabricated in 0.13-m and 90-nm CMOS processes, and are successfully tested. We have also proposed a linearization method, which is specifically applicable to mixers and low-noise-amplifiers (LNAs). A proof-of-concept circuit for the proposed linearization technique is also designed and implemented in a 0.13-m CMOS process and is successfully tested.
Request :
I am interested in Mixers, Modulators and nonlinear circuits . If you have any new interesting idea/article please share that with me .  Thanks. Amir :)

A.H Masnadi; Nikpaik, Amir; Molavi, Reza; Mirabbasi, Shahriar; Shekhar, Sudip, "A Class-C self-mixing-VCO architecture with high tuning-range and low phase-noise for mm-wave applications," in IEEE Radio Frequency Integrated Circuits Symposium (RFIC), 2015, vol., no., pp.107-110, 17-19 May 2015  Link , PDF

            Abstract: Achieving high tuning-range and low phase-noise simultaneously in mm-wave voltage-controlled oscillators (VCO) has been a severe design challenge. Our architecture, referred herein as a self-mixing VCO (SMV), utilizes a Class-C push-push VCO topology to generate the first (f0) and second harmonics (2f0) and then mixes them together to obtain the desired third harmonic (3f0) component. Compared to a fundamental-mode VCO operating at 3f0 in mm-wave band, the SMV architecture achieves superior frequency tuning range (FTR) and phase-noise (PN) performance. A Class-C topology enhances the second-harmonic content to improve mixing efficiency, decreases parasitic capacitance and reduces phase noise. A 52.8-to-62.5 GHz SMV prototype is designed and implemented in a 0.13-m CMOS process. Measurement results show an FTR of 16.8% together with a PN of -100.57 dBc/Hz at 1 MHz offset - resulting in an FTR-inclusive figure-of-merit (FOMT) of -190.85 dBc/Hz while consuming 7.6 mW from a 1.2 V supply voltage.        

Nikpaik, A.; Nabavi, A.; Shirazi, A.H.M.; Shekhar, S.; Mirabbasi, S., "A dual-tank LC VCO topology approaching towards the maximum thermodynamically-achievable oscillator FoM," in IEEE Custom Integrated Circuits Conference (CICC), 2015 , vol., no., pp.1-4, 28-30 Sept. 2015 Link , PDF

            Abstract: There exists a fundamental limit in improving the phase noise performance of LC-tank oscillators. Impediments to reach this limit are first discussed, and then a clipping LC VCO topology based on dual tank is presented to mitigate them. This topology can approach within 3 dB of the maximum thermodynamically achievable figure-of-merit (FoM) limit. Compared to conventional class-B/C/D/F oscillators, it is capable of reducing both close-in and far-out phase noise. As a proof of concept, a prototype 4.17-4.95 GHz VCO in a 0.13-m CMOS process achieves a phase noise of -97 and -143 dBc/Hz at 30 kHz and 3 MHz offset, respectively.