A Sub-1-V, 350-uW, 6.5-dB Integrated NF Low-IF Receiver Front-End for IoT in 28-nm CMOS

This letter presents a highly efficient low-intermediate frequency receiver front-end for Internet-of-Things applications. The lownoise trans-impedance amplifier (LNTA) combines a transformer-based network for scaling up the source impedance together with passive gmboosting and current-reuse techniques to achieve better noise and 12× current saving compared with a common-gate (CG) stage. A complex channel-selection filter with center frequency and passband of 2 and 1.4 MHz, respectively, is implemented after the passive mixer with a gmboosted CG stage. Built in 28-nm CMOS, the proposed receiver occupies an active area of 0.1 mm 2 , it is supplied with 0.9 V and consumes only 350 μW, while showing a minimum NF of 6.2 dB at the channel of interest. The RF performance of the proposed receiver is very competitive with the state-of-the-art ultralow-power receivers, while it consumes the lowest power

A Baseband-Noise-Cancelling Mixer-First CMOS Receiver Frontend Attaining 220 MHz IF Bandwidth With Positive-Capacitive-Feedback TIA

In this paper, by using the baseband noise cancellation, a CMOS mixer-first analog receiver with power reduction is proposed. Based on a current-mirror transimpedance amplifier structure, positive capacitive feedback is applied to manipulate poles/zeros location, enabling a wide baseband bandwidth and out-of-band second-order filtering profile. The additional radio frequency N-path filtering and baseband 40dB/dec roll-off absorb out-of-band interferences. The presented receiver frontend is fabricated in a standard 65 nm CMOS process. Measured results demonstrate a minimal noise figure of 2.2 dB, and an average voltage gain of 32.2 dB across the 220 MHz intermediate frequency range. The in-band and out-of-band third-order input intercept point manifests −12.8 dBm and 15.5 dBm respectively. The presented receiver circuit draws $\sim$ 32 mW at a typical 1 GHz local oscillator stimulus

Mechanistic Studies of Enhanced PCR Using PEGylated PEI-Entrapped Gold Nanoparticles

The polymerase chain reaction (PCR) is considered an excellent technique and is widely used in both molecular biology research and various clinical applications. However, the presence of byproducts and low output are limitations generally associated with this technique. Recently, the use of nanoparticles (NPs) has been shown to be very effective at enhancing PCR. Although mechanisms underlying this process have been suggested, most of them are mainly based on PCR results under certain situations without abundant systematic experimental strategy. In order to overcome these challenges, we synthesized a series of polyethylene glycol (PEG)-modified polyethylenimine (PEI)-entrapped gold nanoparticles (PEG–Au PENPs), each having different gold contents. The role of the synthesized NPs in improving the PCR technique was then systematically evaluated using the error-prone two-round PCR and GC-rich PCR (74% GC content). Our results suggest a possible mechanism of PCR enhancement. In the error-prone two-round PCR system, the improvement of the specificity and efficiency of the technique using the PEG–Au PENPs mainly depends on surface-charge-mediated electrostatic interactions. In the GC-rich PCR system, thermal conduction may be the dominant factor. These important findings offer a breakthrough in understanding the mechanisms involved in improving PCR amplification, as well as in the application of nanomaterials in different fields, particularly in biology and medicine