Nicodimus Retdian

Voltage controlled ring oscillator with wide tuning range and fast voltage swing

A new design of a voltage controlled ring oscillator is proposed. The proposed design allows an implementation of a low frequency ring oscillator using relatively small devices and less stages. A voltage controlled ring oscillator with tuning range from 40 Hz to 380 MHz is achieved using the proposed method. In addition, the proposed circuit enables the output voltage to swing faster than the conventional one.

Gain-Bandwidth Limitations of 0.18μm Si-CMOS RF technology

In this paper, gain bandwidth limitations of a regularly processed 0.18 mum Si CMOS FET is investigated over the frequency band of 450 MHz-10 GHz. It is exhibited that 0.18 mum Si CMOS processing technology can safely be utilized to manufacture ultra wideband RF-amplifiers for commercial wireless communication systems placed silicon chips up to X-Band.

Low-power leapfrog bandpass filter with transmission zeros using integrators and resistor-based addition circuits

This paper proposes an approach to realize a leapfrog filter with transmission zeros by using OTA-C integrators and resistor-based addition circuit instead of OTAs. This method has advantages of reduced number of active elements and spread of element values. A tenth-order bandpass filter is presented as a design example.

Real-frequency design of an integrated lumped element broadband impedance transforming filter

In this paper, design of a broadband lumped element Transformer/Filter (or in short Trans-Filter) is presented. The “Trans-Filter” transforms 12Ω to 50Ω over the frequency band of 100 MHz-2.2GHz. The designed trans-filter is implemented on a 0.18μm CMOS process (6 metals). Simulation results using ideal and actual models are shown to show the effect of non-idealities due to parasitic elements.

Multi-path filters robust to substrate noise and nonlinearity

This paper proposes structures of multi-path filters robust to substrate noise and nonlinearity of elements under low supply voltage to achieve wide dynamic range. They are derived by combining two structures which have been known to suppress substrate noise and nonlinearity more than the balanced one. Dynamic ranges and substrate noises of three proposed structures, the balanced (two-path) one, and the single ended (one-path) one are examined and simulation results show that the proposed structures reduce substrate noise and nonlinearity more than the conventional structures.

Gain-Bandwidth Properties of 0.18μm Si-CMOS Transistor up to 10 GHz

In this paper, gain bandwidth limitations of a regularly processed 0.18 μm Si CMOS FET is investigated over the frequency band of 450 MHz-10 GHz. It is exhibited that 0.18 μm Si CMOS processing technology can safely be utilized to manufacture ultra wideband RF-amplifiers for commercial wireless communication systems placed on a single chip up to X-Band.

Improvement of Bootstrapped Switch using Track and Precharge Phase

This paper discusses the input range limitation problems in track-and-hold circuit and the compensation method using a bootstrapped switch. A bootstrapped switch with an additional control circuit is proposed to compensate charge loss in conventional bootstrapped switch circuit. Simulation results using 0.18 mum CMOS process parameters show that the proposed circuit reduces the bootstrap capacitance down to 25% for the conventional circuit.

Design optimization of staggered amplifier for wide-band applications

This paper proposes a design optimization of staggered amplifier for wide-band applications. The optimization is divided into two simple steps and is independent of circuit topology. It uses the trade-off between power dissipation and area consumption as design constrains. Simulation result using SpectreRF shows that the proposed method gives a good approximation on parameter values.