Nonlinear amplifiers such as the transistor are ubiquitous in classical technology, but their quantum analogues not well understood. We introduce a class of nonlinear that amplify any normal operator and add only half-quantum vacuum noise at output. In large-gain limit, when used conjunction with noisy linear detector, these implement ideal measurements operator.

We generalize the standard quantum model (Caves 1982 Phys. Rev. D 26 1817) of the noise properties of ideal linear amplifiers to include the possibility of non-ideal behavior. We find that under many conditions the non-ideal behavior can be described simply by assuming that the internal noise source that describes the quantum noise of the amplifier is not in its ground state. We validate this m...

In this work, we analyze the effects of an inter-stage capacitor located between the power stage input and the driver stage output on the overall efficiency of a RF CMOS power amplifier and on gate-drain reliability problems. To verify the analyzed effects, we designed a RF CMOS power amplifier with a center frequency of 1.85GHz. Class-D amplifiers with a feedback resistor are used as driver st...

A recent sequence of works, initially motivated by the study of the nonlocal properties of entanglement, demonstrate that a source of information-theoretically certified randomness can be constructed based only on two simple assumptions: the prior existence of a short random seed and the ability to ensure that two black-box devices do not communicate (i.e. are non-signaling). We call protocols ...

As the mobile phone is an essential accessory for everyone nowadays, predistortion for the RF power amplifiers in mobile phone systems becomes more and more popular. Especially, new predistortions for power amplifiers with both nonlinearities and memory effects interest the researchers. In our thesis, novel predistortion techniques are presented for this purpose. Firstly, we improve the digital...