New technologies such as quantum-dot cellular automata(QCA) have been showing some remarkable characteristics that standard complementary-metal-oxide semiconductor(CMOS) in deep sub-micron cannot afford. Modeling syst...New technologies such as quantum-dot cellular automata(QCA) have been showing some remarkable characteristics that standard complementary-metal-oxide semiconductor(CMOS) in deep sub-micron cannot afford. Modeling systems and designing multiple-valued logic gates with QCA have advantages that facilitate the design of complicated logic circuits. In this paper, we propose a novel creative concept for quaternary QCA(QQCA). The concept has been set in QCASim, the new simulator developed by our team exclusively for QCAs’ quaternary mode. Proposed basic quaternary logic gates such as MIN, MAX, and different types of inverters(SQI, PQI, NQI, and IQI) have been designed and verified by QCASim. This study will exemplify how fast and accurately QCASim works by its handy set of CAD tools. A 1×4 decoder is presented using our proposed main gates.Preference points such as the minimum delay, area, and complexity have been achieved in this work. QQCA main logic gates are compared with quaternary gates based on carbon nanotube field-effect transistor(CNFET). The results show that the proposed design is more efficient in terms of latency and energy consumption.展开更多
Designing logic circuits using complementary metal-oxide-semiconductor(CMOS)technology at the nano scale has been faced with various challenges recently.Undesirable leakage currents,the short-effect channel,and high e...Designing logic circuits using complementary metal-oxide-semiconductor(CMOS)technology at the nano scale has been faced with various challenges recently.Undesirable leakage currents,the short-effect channel,and high energy dissipation are some of the concerns.Quantum-dot cellular automata(QCA)represent an appropriate alternative for possible CMOS replacement in the future because it consumes an insignificant amount of energy compared to the standard CMOS.The key point of designing arithmetic circuits is based on the structure of a 1-bit full adder.A low-complexity full adder block is beneficial for developing various intricate structures.This paper represents scalable 1-bit QCA full adder structures based on cell interaction.Our proposed full adders encompass preference aspects of QCA design,such as a low number of cells used,low latency,and small area occupation.Also,the proposed structures have been expanded to larger circuits,including a 4-bit ripple carry adder(RCA),a 4-bit ripple borrow subtractor(RBS),an add/sub circuit,and a 2-bit array multiplier.All designs were simulated and verified using QCA Designer-E version 2.2.This tool can estimate the energy dissipation as well as evaluate the performance of the circuits.Simulation results showed that the proposed designs are efficient in complexity,area,latency,cost,and energy dissipation.展开更多
We propose a feedback type oscillator and two negative resistance oscillators.These microwave oscillators have been designed in the S band frequency.A relatively symmetric resonator is used in the feedback type oscill...We propose a feedback type oscillator and two negative resistance oscillators.These microwave oscillators have been designed in the S band frequency.A relatively symmetric resonator is used in the feedback type oscillator.The first negative resistance oscillator uses a simple lumped element resonator which is substituted by a microstrip resonator in the second oscillator to improve results.The negative resistance oscillator produces 4.207 dBm and 7.124 dBm output power with the lumped element resonator and microstrip resonator respectively,and the feedback type oscillator produces ?10.707 dBm output power.The feedback type oscillator operates at 3 GHz with phase noise levels at-83.30 dBc/Hz and-103.3 dBc/Hz at 100 kHz and 1 MHz offset frequencies respectively.The phase noise levels of the negative resistance oscillator with the lumped element resonator are-94.64 dBc/Hz and-116 dBc/Hz at 100 kHz and 1 MHz offset frequencies respectively,at an oscillation frequency of 3.053 GHz.With the microstrip resonator the phase noise levels are-99.49 dBc/Hz and-119.641 dBc/Hz at 100 kHz and 1 MHz offset frequencies respectively,at an oscillation frequency of 3.072 GHz.The results showed that both the output power and the phase noise of the negative resistance oscillators were better than those of the feedback type oscillator.展开更多
文摘New technologies such as quantum-dot cellular automata(QCA) have been showing some remarkable characteristics that standard complementary-metal-oxide semiconductor(CMOS) in deep sub-micron cannot afford. Modeling systems and designing multiple-valued logic gates with QCA have advantages that facilitate the design of complicated logic circuits. In this paper, we propose a novel creative concept for quaternary QCA(QQCA). The concept has been set in QCASim, the new simulator developed by our team exclusively for QCAs’ quaternary mode. Proposed basic quaternary logic gates such as MIN, MAX, and different types of inverters(SQI, PQI, NQI, and IQI) have been designed and verified by QCASim. This study will exemplify how fast and accurately QCASim works by its handy set of CAD tools. A 1×4 decoder is presented using our proposed main gates.Preference points such as the minimum delay, area, and complexity have been achieved in this work. QQCA main logic gates are compared with quaternary gates based on carbon nanotube field-effect transistor(CNFET). The results show that the proposed design is more efficient in terms of latency and energy consumption.
文摘Designing logic circuits using complementary metal-oxide-semiconductor(CMOS)technology at the nano scale has been faced with various challenges recently.Undesirable leakage currents,the short-effect channel,and high energy dissipation are some of the concerns.Quantum-dot cellular automata(QCA)represent an appropriate alternative for possible CMOS replacement in the future because it consumes an insignificant amount of energy compared to the standard CMOS.The key point of designing arithmetic circuits is based on the structure of a 1-bit full adder.A low-complexity full adder block is beneficial for developing various intricate structures.This paper represents scalable 1-bit QCA full adder structures based on cell interaction.Our proposed full adders encompass preference aspects of QCA design,such as a low number of cells used,low latency,and small area occupation.Also,the proposed structures have been expanded to larger circuits,including a 4-bit ripple carry adder(RCA),a 4-bit ripple borrow subtractor(RBS),an add/sub circuit,and a 2-bit array multiplier.All designs were simulated and verified using QCA Designer-E version 2.2.This tool can estimate the energy dissipation as well as evaluate the performance of the circuits.Simulation results showed that the proposed designs are efficient in complexity,area,latency,cost,and energy dissipation.
文摘We propose a feedback type oscillator and two negative resistance oscillators.These microwave oscillators have been designed in the S band frequency.A relatively symmetric resonator is used in the feedback type oscillator.The first negative resistance oscillator uses a simple lumped element resonator which is substituted by a microstrip resonator in the second oscillator to improve results.The negative resistance oscillator produces 4.207 dBm and 7.124 dBm output power with the lumped element resonator and microstrip resonator respectively,and the feedback type oscillator produces ?10.707 dBm output power.The feedback type oscillator operates at 3 GHz with phase noise levels at-83.30 dBc/Hz and-103.3 dBc/Hz at 100 kHz and 1 MHz offset frequencies respectively.The phase noise levels of the negative resistance oscillator with the lumped element resonator are-94.64 dBc/Hz and-116 dBc/Hz at 100 kHz and 1 MHz offset frequencies respectively,at an oscillation frequency of 3.053 GHz.With the microstrip resonator the phase noise levels are-99.49 dBc/Hz and-119.641 dBc/Hz at 100 kHz and 1 MHz offset frequencies respectively,at an oscillation frequency of 3.072 GHz.The results showed that both the output power and the phase noise of the negative resistance oscillators were better than those of the feedback type oscillator.
