Numerical analysis of a bilayer graphene nanoribbon (BLGNR) using the reproducing kernel particle method (RKPM)a true meshless approachis reported. Electrostatic analysis of the BLGNR is performed using the RKPM approach. Validation of the structure is executed by comparing the result with an equivalent single conductor model and shows better accordance. Radio frequency (RF) analysis of the BLGNR as the interconnect is studied using advanced design systems with the quasi-static analysis derived through the RKPM method. The simulation results in a return loss of −89.69 dB and transmission loss of −0.00028 dB at 1 THz which is suitable for RF interconnect applications.

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In this paper, we present the design of a low voltage bandgap reference (LVBGR) circuit for supply voltage of 1.2V which can generate an output reference voltage of 0.363V. Traditional BJT based bandgap reference circuits give very precise output reference but power and area consumed by these BJT devices is larger so for low supply bandgap reference we chose MOSFETs operating in subthreshold region based reference circuits. LVBGR circuits with less sensitivity to supply voltage and temperature is used in both analog and digital circuits like high precise comparators used in data converter, phase-locked loop, ring oscillator, memory systems, implantable biomedical product etc. In the proposed circuit subthreshold MOSFETs temperature characteristics are used to achieve temperature compensation of output voltage reference and it can work under very low supply voltage. A PMOS structure 2stage opamp which will be operating in subthreshold region is designed for the proposed LVBGR circuit whose gain is 89.6dB and phase margin is 74 °. Finally a LVBGR circuit is designed which generates output voltage reference of 0.364V given with supply voltage of 1.2 V with 10 % variation and temperature coefficient of 240ppm/ °C is obtained for output reference voltage variation with respect to temperature over a range of 0 to 100°C. The output reference voltage exhibits a variation of 230µV with a supply range of 1.08V to 1.32V at typical process corner. The proposed LVBGR circuit for 1.2V supply is designed with the Mentor Graphics Pyxis tool using 130nm technology with EldoSpice simulator. Overall current consumed by the circuit is 900nA and also the power consumed by the entire LVBGR circuit is 0.9µW and the PSRR of the LVBGR circuit is -70dB.

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To achieve high data rate, large system capacity and multimedia services the next generation wireless communication system uses a multiple access technique such as Multi Carrier Code Division Multiple Access (MC-CDMA). It is actually the mixture of two efficient techniques such as CDMA and OFDM. The CDMA part enhances the spectrum utilization whereas the OFDM part reduces multipath fading and ISI. The OFDM technique uses narrowband signal to reduce the frequency selective multipath fading because narrowband signal are less sensitive to ISI and frequency selective multipath fading. The spreading sequences used in a CDMA system have an efficient role in interference reduction and spectrum utilization. With the use of efficient spreading sequence the system enjoys low interference. The performance of the system will depend upon the correlation properties and length of the spreading sequences used. In this paper we are suggesting a novel coding technique which may further improve the system performance in terms of bit error rate (BER) with the use of Low Density Parity Check (LDPC) codes as the error correcting code. An intensive comparative study were carried out to compare the performance of MC-CDMA system in terms of BER Vs SNR and P APR Vs CCDF curves based on the coding techniques such as Walsh-Hadamard (WH) code and Zero Correlation Zone (ZCZ) code.