A single-chip Si-bipolar 1.6-GHz VCO with integrated-bias network

A single-chip 2.7-V voltage-controlled oscillator (VCO) with an integrated-bias network has been implemented in an Si-bipolar process with an f_T of 25 GHz. With an on-chip resonator consisting of vertically coupled inductors and varactor diodes, an oscillation frequency of 1.56 GHz was measured. A careful design of the oscillator and bias network was necessary to achieve a phase noise performance of -139 dBc/Hz at 4.7 h MHz off carrier. The tuning sensitivity was 100 MHz/V, which is sufficient to compensate for production tolerances. The VCO can be used as a building block for single-chip transceivers in digital European cordless telephone or global system for mobile communication systems     

Low‐noise,low‐voltage,low‐power IF gain controlled amplifiers for wireless communication

Circuit solutions of various types of gain controlled IF amplifiers with digital and analog gain control are described. Advantages and disadvantages of the different solutions are shown. Requirements for lowpower, lowvoltage, low noise, high gain and linearity at high IFfrequencies from the system point of view are worked out. Solutions will be presented to optain optimum performance by technology and circuit design technique for digital wireless telephone systems used for GSM and PCN systems.     

A Si 1.8 GHz RLC filter with tunable center frequency and qualityfactor

A second-order active bandpass filter using integrated inductors was implemented in Si bipolar technology. The filter uses special techniques to make the quality factor and the center frequency tunable. For a nominal center frequency of 1.8 GHz and a quality factor of 35, the filter has 1 dB compression dynamic range of 40 dB, and draws 8.7 mA from a 2.8 V supply     

Fully integrated W-CDMA IF receiver and IF transmitter including IFsynthesizer and on-chip VCO for UMTS mobiles

A fully integrated, dual intermediate frequency (IF) receiver and an IF transmitter, each with on-chip IF synthesizer, for use in third-generation wide-band code division multiple access (W-CDMA) mobiles has been implemented in a standard, high-frequency, Si-bipolar process with an f_T of 25 GHz. The IF receiver (318 MHz) and IF transmitter (285 MHz) include a complete phase-locked loop (PLL) and on-chip voltage-controlled oscillator (VCO) with integrated varactors and transformers. The VCOs are used for on-chip local oscillator (LO) generation and operate at four times IF, 1272 MHz and 1140 MHz, for Rx and Tx, respectively. Fully integrated, active, analog base-band filters further increase functionality and integration level. In the receiver, a channel select filter, composed of a fifth-order Chebyshev lowpass filter and a first-order all-pass filter, is implemented. In the transmitter, a fifth-order Butterworth low-pass filter functions as a reconstruction filter. Both devices operate on 2.7-3.3-V supply. The designs comply with ARIB W-CDMA and UMTS standards. Each chip is mounted in a small outline, 32-pin, leadless surface mount package     

Transceiver architectures for W-CDMA mobile terminal applications

Eligible transceiver architectures for third-generation Wide-Band Code Division Multiple Access (W-CDMA) mobile terminal application are presented. The heterodyne, homodyne, and low-IF architecture are discussed in detail with respect to their specific properties regarding W-CDMA. The considered issues include topics like system requirements, technical performance parameters, integration level possibilities as well as general topics like system cost and development effort.     

Integration spannungsabstimmbarer Oszillatoren für Mobilfunkanwendungen

The frequency concepts of GSM and DECT systems in mobile handsets consist mainly of three voltage controlled oscillators. The goal of this work is the integration of these oscillators with a bipolar technology. In this paper the requirements for the oscillators are shown. The possibilities of integration are examined theoretically and by experiment. For the GSM system a partly integrated solution is demonstrated and for the DECT system a fully integrated VCO is presented.     

A fully integrated VCO at 2 GHz

A fully integrated voltage-controlled oscillator at a frequency of 2 GHz with low phase noise has been implemented in a standard bipolar process with a f_t of 25 GHz. The design is based on an LC-resonator with vertical-coupled inductors. Only two metal layers have been used. The supply voltage of the oscillator is 2.7 V. The phase noise is only -136 dB/Hz at 4.7 MHz frequency offset. A tuning range of 150 MHz is achieved with integrated tuning diodes     

Flow Field Simulation and Measurement in Packed Beds Based on 4D-X-Ray Computed Tomography

X-ray computed tomography (XCT) combined with computational fluid dynamics (CFD) simulations have proved to be a powerful and versatile tool to describe fluids flow through packed bed systems. In this contribution, two examples of the application of XCT experiments to track the fluid flow and fluid penetration in packed bed systems are shown. The first one shows how geometrical information extracted from XCT measurements can be coupled to CFD simulations to assess fluid flows reliably. Here the example of a packed bed of three-dimensional (3D) printed cylindrical-shaped particles is considered. Finally, a short case study on the monitoring of the progress of the water penetration front in a packed bed composed of glass spheres using four-dimensional (4D) XCT imaging data is presented.