Julien Lintignat

A Class of Microwave Transversal Signal-Interference Dual-Passband Planar Filters

A new type of microwave dual-passband planar filter exploiting signal-interference techniques is presented. The described filter approach consists of transversal filtering sections shaped by two transmission lines connected in parallel. This transversal section, operating under feedforward signal-combination principles, allows dual-band bandpass filtering responses with several transmission zeros to be synthesized. A set of analytical formulas and guidelines for the design of the dual-passband transversal filtering section are provided. Moreover, its practical usefulness is verified through the development and testing of a microstrip prototype for the 1.4/2.6-GHz dual band.

Silicon-Integrated Differential Bandpass Filters Based on Recursive and Channelized Principles and Methodology to Compute Their Exact Noise Figure

In this paper, two silicon-integrated differential active bandpass filters are presented. The first one is a recursive filter based on a cellular approach. This circuit is independently tunable in terms of power transmission gain, center frequency, and bandwidth. The chip surface is less than 1.4 mm2. For this prototype, measurements demonstrate a 1.9-2.4-GHz center-frequency tuning range with a typical gain of 15 dB and a 3-dB bandwidth of 60 MHz. Gains of up to 40 dB and bandwidths as low as 20 MHz are also achievable in the 2.05-2.38-GHz range. Subsequently, the design of an integrated three-branch channelized bandpass filter is addressed. The proposed filter uses an active power splitter at its input. Moreover, the channels are based on elementary first-order tunable recursive stages derived from the previously described topology, thus making the overall filter fully reconfigurable. This second circuit, whose layout size is smaller than 3 mm2, can exhibit 3-dB bandwidths of ap90 MHz and gains of up to 20 dB within a 1.95-2.23-GHz tuning range. Controllable high selectivity for each rejected band can be obtained through the generation of adjustable out-of-band transmission zeros. Furthermore, a dual-band behavior is also feasible through this filter. To conclude, an original method to extract the exact noise figure of differential circuits is reported, and applied to the filter prototypes developed in this study. The Philips QUBIC4 0.25-mum silicon BiCMOS process has been used for the design of the two circuits presented

Silicon-Integrated 2-GHz Fully-Differential Tunable Recursive Filter for MMIC Three-Branch Channelized Bandpass Filter Design

In this paper, a silicon-integrated differential-type two-stage recursive active filter based on a cellular approach is presented. This circuit is independently tunable in terms of power transmission gain, center frequency and bandwidth. The chip surface is less than 1.4 mm2. Measurements demonstrate a 1.9-2.4 GHz center-frequency tuning range with a typical gain of 15 dB and a 3-dB bandwidth of 60 MHz. Gains up to 40 dB and bandwidths as low as 20 MHz are also achievable in the 2.05-2.38 GHz band. In the next step, the design of an integrated three-branch channelized bandpass filter is addressed. To the authors knowledge, this is the first MMIC channelized filter reported to date. The proposed filter uses an active power splitter at its input. Moreover, the branches are based on an elementary tunable recursive stage derived from the topology previously described, thus making the overall filter fully reconfigurable. This second circuit, which chip size is smaller than 3 mm2, can perform 3-dB bandwidths of approximately 90 MHz and gains up to 20 dB within a 2-2.2 GHz tuning range. Controllable high-selectivity for each rejected band is also obtained through the generation of adjustable out-of-band transmission zeros. These two chips have been implemented using Philips QUBIC4 Si BiCMOS process (Szmyd et al., 2001)

Original approach for extracting the exact noise factor of differential microwave circuits using mixed-mode and noise-wave formalisms

In this paper, an analytical approach to study the noise figure of differential amplifiers is presented. First, the analytical expression of the noise figure for a four-port device is determined thanks to the use of a generalised method based on the noise-wave formalism. Then, the use of ideal baluns for the simulation of the noise figure is discussed in regards to the accuracy of the results. An analytical solution that can be implemented in a CAD software to get the correct and exact differential mode noise figure is proposed. Finally, in order to illustrate the purpose, the method is applied to the study of a differential three-branch channelized filter

Lumped-element-based single/dual-passband analog filters using signal-interference principles

An original type of lumped-element analog filters based on signal-interference techniques is proposed in this paper. To this aim, a novel class of two-path transversal filtering section shaped by a lumped-element quadrature power coupler arranged in reflection mode is devised as basic building block. Thus, under feedforward signal-interaction effects generated in this circuit network, high-performance filtering functions can be produced. As synthesis examples, two different multi-stage designs corresponding to ultra-wideband single-band and dual-band bandpass filters are demonstrated. Furthermore, for the previous ultra-wideband bandpass filter example, two alternative implementations at the layout level are developed for practical verification.

High Resistive Silicon based low-pass active filter design for TV on mobile application

This paper deals with the design of a novel low-pass active filter for UHF band digital TV reception which enables to attenuate interfering GSM signals located in the 900MHz band. An hybrid technology is employed for this design combining High Resistive Silicon (HR-Si) technology and common printed circuit board (PCB) one. The designed active filter is based on a lumped element 11-pole generalized Chebyshev filter associated to a negative resistance such as to compensate for the overall insertion loss and enhance the filter selectivity. All the lumped elements of the passive filter are integrated in the HR-Si substrate while the negative resistance is designed onto a FR4-based PCB. The complete design has been fully simulated and experimental prototypes realized and measured, demonstrating the benefits of the proposed design.

Tunable low-pass active filter using active capacitor for multimode standards

This paper presents a novel tunable low-pass active filter aiming to protect the DVB-H receiver against the signals coming simultaneously from the GSM band and from the Digital dividend band. The filter concept is based on a high order low pass filter at which an active capacitor circuit has been added. This later allows to compensate the overall losses of the filter and makes it tunable for a worldwide usability.

A high linearity low-noise amplifier in 0.25 μm BiCMOS Qubic4x for GSM application

ABSTRACT In this paper, a low-noise amplifier (LNA) in 0.25 μm BiCMOS Qubic4x technology for Global System for Mobile communications (GSM) application is presented. The LNA uses inductive source degeneration to achieve noise and power gain matching simultaneously and parallel RC feedback to improve linearity. The LNA provides a forward gain (S21) of 10.3 dB with noise figure (NF) of 1.5 dB while drawing 50.6 mW power from a 1.6 V voltage supply. The simulated 1-dB compression point is 0 dBm at 942 MHz. The simulations are done in cadence virtuoso Spectre RF using 0.25 μm BiCMOS Qubic4x technology.

Lumped-element RF analog multi-band bandpass filter concept for software-defined-radio architectures

Future software-defined radios (SDRs) for modern wireless applications—e.g., 5G communications—could require reconfigurable RF analog circuits to enable multistandard/service operation with hardware miniaturization. In this context, a lumped-element multi-band bandpass filter concept is presented. This filter architecture consists of the in-series cascade of several multi-transmission-zero-(TZ)-generation cells that are shaped by a plurality of series-type resonant branches. It allows to synthesize multi-band transfer functions with arbitrary order and number of passbands with inter-band TZs. A theoretical analysis of the proposed multi-passband filter scheme is expounded. Also, its potential for fully-reconfigurable multi-band bandpass filter realization through TZ reallocation is studied at the ideal-design level.

Self calibrating high sensitivity ultra-low power envelope detector

An amplitude demodulation system is described here. An envelope detector is connected to the non inverting input of a differential amplifier whereas a reference voltage is applied to its inverting input. This reference is established during a self calibration process and compensates the input offset of the differential amplifier. This mechanism has been designed and implemented within the circuit described in this paper. The circuit is designed in a 160 nm Complementary Metal Oxide Semiconductor process. A sensitivity of -30 dBm is achieved. It can operate over a wide frequency and temperature ranges, 100 MHz-3 GHz and -55 °C-125 °C respectively. It consumes only a few microwatts.