a digital look-up table adaptive predistortion technique using a six-port receiver for power amplifier linearization is presented. the system is designed in ka-band for a dvb-s2 satellite link. we use a six-port receiver at the linearizationloop in place of classic heterodyne receivers. the six-port receiver is implemented by the use of passive microwavecircuits and detector diodes. this approa...

A novel distributed transversal filter technique for code division multiple access systems is proposed. It is observed that the distributed amplifier principle underlying the filter approach enables the generation of multi-gigahertz waveforms with suitable accuracy. The DTF method is considered in the context of phase-addressing code division multiplexing systems. Simulation results based on a ...

For the past few years, we have been researching a novel type of photodetector featuring distributed optical amplification. We call these devices traveling-wave amplifier-photodetectors, or TAP detectors. The distributed combination of gain and absorption seeks a larger efficiency while keeping a low optical power, thus avoiding saturation. In this paper, we present experimental results both of...

A Class-E/Fodd high power amplifier (PA) using the distributed active transformer (DAT) is demonstrated at 29MHz. The DAT combines the output power from four VDMOS push-pull pairs. The zero voltage switching (ZVS) condition is investigated and modified for the Class-E/Fodd amplifier with a non-ideal output transformer. All lumped elements including the DAT and the transistor package are modeled...

A two-stage fiber-based femtosecond amplification system is presented, based on chirped-pulse amplification in highly nonlinear regime. The amount of self-phase modulation is separately adjusted in each stage selecting the proper stretching ratio in order to compensate gain narrowing. Analytical design rules are validated using numerical simulations. Our experimental implementation leads to the...

Distributed circuits using transmission lines (T-lines) or inductors exhibit high gain-bandwidth-products (GBW), as required by broadband communication systems. In this paper, the design of non-uniform downsized distributed amplifiers (DAs) is explored. Conventional DAs employ a topology in which inductors or T-lines separate the gain stages, yet the output currents from individual stages combi...

Ever since its discovery, graphene bears great expectations in high frequency electronics due to its irreplaceably high carrier mobility. However, it has long been blamed for the weakness in generating gains, which seriously limits its pace of development. Distributed amplification, on the other hand, has successfully been used in conventional semiconductors to increase the amplifiers' gain-ban...

..-htracf —A high-speed CMOS comparator has been designed and fabricated using a standard 3pm process. A dynamic latch preceded by an offset-cancelled amplifier is used to obtain a response time of 43 ns. The offset-cancelled amplifier reduces the input-referred offset so that medium-resolution analog-to-digital converters (ADC’S) can be built with this comparator. The use of pipefining within ...

Previously reported quasi-optical amplifier arrays have limited bandwidth and suffer from poor input/output isolation. These prsbllems can be solved by using traveling wave antennas and distributed amplifier techniques. FII'TD simulations of a linearly tapered slot array topology demonstrate very broadband quasioptical transitions are feasible with small unitcell aperture. Experiments using a s...