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In this study, the growth of Escherichia coli was monitored using a complementary metal-oxide-semiconductor (CMOS) near-field sensor array. Each of the 1488 integrated elements, arranged in a 3 mm square, has a resonator that oscillates at 65 GHz. The effective capacitance of the resonator is altered by changes in the dielectric properties of the sensor surface, which shifts the resonance frequency. Growth curves of E. coli at different initial concentrations (OD600 = 0.01, 0.03, and 0.05) were monitored. A suspension with initial turbidity of OD600 = 0.05 was cultured in a medium, and the sensor successfully distinguished between viable E. coli and heat-treated dead E. coli in 20 min. Moreover, the apparent suppression of growth was observed in the presence of 500 μg/mL streptomycin. As the sensor is composed of arrayed elements, and the area of sensitivity distribution of the element is larger than the size of one bacteria, the variation in the output value of each element may reflect the number and movement of bacteria. This study revealed that the presence of viable E. coli could be rapidly confirmed by using the change in permittivity caused by the displacement of media by E. coli near the sensor surface.

In this paper, we demonstrated parallelized detection of fluorescent microbeads flowing in multiple microfluidic channels coupled with an array of single photon avalanche diodes (SPADs). A complementary metal-oxide-semiconductor (CMOS)-integrated circuit (IC) containing an SPAD array was used for time-domain separation of fluorescence photons from excitation photons using fast gating and active quenching circuits to realize parallelized detection of fluorescence signals without complex microscopy and optical filters. The system can be used for the development of a parallelized flow cytometry system.

For label-free single-cell detection, a CMOS biosensor integrated circuit (IC) with 360-sensing elements using 63-GHz LC-oscillator and single-cell trapping electrode is proposed. To realize a label-free biosensor, we have focused on frequencies around 60 GHz where changes in the dielectric constant of water become prominent as many a water molecule is bound to biomolecules, we reported an LC-oscillator based sensor previously. LC-oscillator based sensor has the highest sensitivity at the center of differential terminals of inductor. To attract single cells onto the sensing position using dielectrophoresis (DEP), cell-sized electrode is placed at the center of the differential electrodes. The measurement results of trapped cells vary widely suggesting the variation of cell volume and cell activity.

RF Variable Gain Amplifiers (RF-VGA) are important components for integrated TV broadcast receivers. Analog and digital controlled RF-VGAs are compared in terms of linearity and an AGC loop architecture suitable for digitally controlled RF-VGA is proposed. Further linearity enhancement applicable for CMOS implementation is also discussed.

We have measured the noise floor of spectrum and phase noise of the proposed differential dual-modulus 10/11 prescaler based on ILFD for various supply voltages and found that spurious noises arise and the phase noise degrades as the supply voltage reduces. The differential dual-modulus prescaler is implemented in 130 nm CMOS process and the core size is 40 × 20 μm2.

In this paper, we present a differential dual-modulus prescaler based on an injection-locked frequency divider (ILFD) for a satellite low noise block (LNB) down converter. Three stage differential latches using ILFD and a cascaded differential divider can achieve divide-by-10/11 operations with a lock range of 2.1 GHz - 10 GHz at a supply voltage of 1.4 V and an operating frequency range of 2.1 GHz - 6.1 GHz at a supply voltage of 1 V. At our target frequency, 5 GHz, a minimum energy of 0.19 pJ (=mW/GHz) at the maximum input frequency can be achieved. Our proposed circuit is fabricated by a 130 nm CMOS process, and the prototype chip core area is 40 × 20 μm2.