No abstract

In this work, the design of a high-frequency AM demodulator in a printed complementary organic technology is presented. The behaviour and the variability of printed circuits are predicted by means of accurate transistor modelling, statistical characterization, and Monte Carlo simulations. The effectiveness of the design approach is readily verified by comparing measurements and simulations of simple digital blocks as well as two differen- tial amplifiers. These amplifiers can be used as continuous-time comparators in the demodulator. In addition, the possibility of high-frequency rectification using the printed organic TFTs is shown by providing the experimental results of an envelope detector mea- sured under different load and input conditions. All the measurements are performed in air. Finally, the simulation of a complete AM demodulator system including the measured blocks is demonstrated

SUMMARYThis paper presents a methodology to design reconfigurable switched-capacitor (SC) delta-sigma modulators Ms) capable of keeping their corresponding power efficiency figures constant and optimal for a set of resolutions and signal bandwidths. This method is especially suitable for lowbandwidth, medium-to-high resolution specifications, which are common in bio-medical application range. The presented methodology is based on an analytic model of all different contributions to the power dissipation of the ΔΣM. In particular, a novel way to predict the static power dissipated by integrators based on class-A and class-AB OTAs is presented. The power-optimal solution is found in terms of filter order, quantizer resolution, oversampling ratio and capacitor dimensions for a targeted resolution and bandwidth. As the size of the sampling capacitors is crucial to determine power consumption, three approaches to achieve reconfigurability are compared: sizing the sampling capacitors to achieve the highest resolution and keep them constant, change only the first sampling capacitor according to the targeted resolution or program all sampling capacitors to the required resolution. The second approach results in the best trade-off between power efficiency and simplicity. A reconfigurable ΔΣM for bio-medical applications is designed at transistor-level in a 0.18μm CMOS process following the methodology discussed. A comparison between the power estimated by the proposed analytic model and the transistor implementation shows a maximum difference of 17%; validating thus the proposed approach.

No abstract

A 1.8GHz RF amplifier implemented in 0.14um CMOS with frequency-independent blocker suppression is presented. The blocker suppression functionality is obtained by the adaptation of a nonlinear input-output transfer according to the blocker amplitude. Since superposition does not apply to nonlinear transfer functions, the behavior of such a transfer for strong undesired signals is different from the behavior for weak desired signals, which is exploited here. In the presence of a 0 to +11 dBm RF blocker, a voltage gain for weak signals of respectively 7.6-9.4 dB and IIP3 >4 dBm are measured, while the blocker is suppressed by more than 35 dB. In case of no blocker present at the input, the circuit is set to amplifier mode providing 17 dB of voltage gain and an IIP3 of 6.6 dBm while consuming 3 mW. Application areas are coexistence in multi-radio devices and dealing with TX leakage in FDD systems.