A wideband optical frequency comb (OFC) generator using a fiber re-circulating loop (FRL) including phase modulator and amplifier, cascaded with spectrum expander containing high-power erbium-doped amplifier highly nonlinear (HNLF) is proposed experimentally demonstrated, in which the FRL used as source to generate seed lines, then generated lines are extended four-wave mixing HNLF. Only one st...

This paper presents a broadband GaN pseudo high-electron-mobility transistor (pHEMT) two-stage driver amplifier based on an enhanced feedback technique for wideband system. Through well-designed parameter values of the and matching structure circuit, relatively flat frequency response was obtained over wide band. Simultaneously, in order to reduce fluctuation current caused by environmental tem...

in this paper a wideband single stage pseudomorphic high electron mobility transistor (PHMET) amplifier has been designed at 5.8 GHz, the input and output matching circuits have a pi form.Noise cancelling principle and sensitivity analysis are performed .Simulation results have been compared with their correspondence in [10] give 2.71 dB improvement in amplifier gain at the same noise figure (N...

Employing 130-nm IBM CMOS model parameters, the design of a power-efficient single-stage microwave amplifier is presented in this paper. An optimization technique for the amplifier forward gain is proposed through careful selection of process elements without compromising the architecture’s high degree of isolation and resistance to reflection-loss. A novel mechanism to match port-impedances of...

The application of digital predistortion in base band signal is an extended method of amplifier linearization to reduce the Adjacent Channel Interference (ACI) in those systems in which a varying envelope modulation scheme like OFDM and MQAM is used. Digital baseband predistortion is a highly cost-effective way to linearize Power amplifiers (PAs), but most existing architectures assume that the...

Radio communication systems of the future will require a large increase in user capacity. To achieve this, cell sizes will reduce and the number of base stations will increase. Current base station architectures use analogue combining techniques which are expensive, voluminous and inflexible. This thesis investigates a Digital Signal Processing (DSP) solution which produces a cheaper, smaller a...

— We report a high data rate (upto 1 Gbps) Ultra-wideband (UWB) transceiver for very low power applications. The transmitter side, including pulse generator (PG), power amplifier (PA) and on-chip antenna, consumes only 7 pJ/b (3 pJ/b w/o PA). The novel UWB on-chip antenna has relatively low loss of 10 dBi and allows for a more compact overall system suitable for area constrained implantable and...

We have developed a liquid-environment atomic force microscope with a wideband and low-noise scanning system for atomic-scale imaging of dynamic processes at solid/liquid interfaces. The developed scanning system consists of a separate-type scanner and a wideband high-voltage amplifier (HVA). By separating an XY-sample scanner from a Z-tip scanner, we have enabled to use a relatively large samp...

Introduction Ultra-wideband (UWB) technology is a promising solution for low-complexity, low cost, low power and high-data rate wireless connectivity among devices in a personal area network. The main signal processing operations involved in a typical analog front end of a UWB receiver before demodulation are frequency translation to baseband, signal amplification and filtering to strengthen th...

Based on the self-developed standard process RF-LDMOS device, a new ultra-wideband RF power amplifier is designed in this letter. The removes absorbing resistor and capacitor series structure at end of drain. stability circuit enhanced by pre-matching circuit. Considering small impedance value high-power it difficult to achieve broadband matching. novel tapering drain transmission has been deve...