Laurent Billonnet

Optimization of noise performance for various topologies of planar microwave active filters using noise wave techniques

In this paper, two types of microwave active filters are studied. First we show how, using a noise wave formalism, the noise factor of three topologies of active recursive filters can be effectively minimized by using appropriate unbalanced power dividers/combiners and an amplifier. A comparison between the different topologies is given. Simulations and practical results are presented and validate our approach. In a second part, the noise wave formalism is applied to /spl lambda//2 microstrip active filters. We show how the appropriate choice of coupling between lines and resonators can achieve low-noise filters. Simulations and practical results are also presented.

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

Design concept for microwave recursive and transversal filters using Lange couplers

The authors focus on the use of Lange couplers in the design of passive recursive and transversal filters in the microwave frequency range. A simple numerical method for the computation of the filter parameters is described. A synthesis example is given to illustrate the techniques for the wideband filter case. It is shown that Lange couplers can be effectively employed in the design of recursive and transversal filters. Analytical, computer-simulated, and experimental results are preserved for two passive bandpass filters which were implemented on a Duroid substrate in the 3-5-GHz frequency range. Good agreement was obtained between the theoretical and the measured S-parameters for the filters.<<ETX>>

Theoretical and experimental analysis of microwave tunable recursive active filters using power dividers

It is shown how power dividers can be effectively employed in the design of microwave recursive filters in strict accordance with low-frequency principles. Analytical, computer-simulated, and experimental results are presented for an active recursive bandpass filter, and for a newly developed tunable recursive active filter employing a reflection-type microwave phase shifter and implemented on a Duroid substrate in the 2.75-3.75-GHz range. The last step in the filter design was to insert a classical reflection-type analog phase shifter structure directly into the recursive loop, to help in the realization of a tunable recursive response. Measured S-parameters of the circuits show excellent agreement with theoretical analysis.<<ETX>>

Stability diagnosis of microwave recursive structures using the NDF methodology

In this paper, we verify and validate the new important concepts developed by W. Struble and A. Platzkerin (see IEEE GaAs IC Symp. Dig., p. 251-4, 1993) by comparing the NDF method to-classical-low frequency concepts which, under some assumptions, can be applied to microwave recursive structures. We proceed with the examples of a first-order and a second-order recursive filters and show how the NDF expression for this kind of filter can be easily identified.<<ETX>>

High-order monolithic active recursive filter based upon multicellular approach

This article deals with a multicellular approach for high-order monolithic active recursive filter design. The transfer function results from a cascade association of first-order recursive cells, each characterizing a single pole. We illustrate our approach with simulated results for a higher-order bandpass filter in the X-band and finally present measurements for the corresponding structures resulting from the cascade association of first-order recursive tunable filters, in MMIC technology.

Highly selective planar filter using negative resistances for loss compensation

This paper deals with the realization of a resonator-based planar passive filter which losses are compensated for by active circuits simulating negative resistances. Most important characteristics of this filter are a high selectivity (bandwidth of this filter is 26.7 MHz around 14.11 GHz) and a low power consumption (30.7 mW).

Analysis of an automatically tuned filter and its application at microwave frequencies

This paper analyses an automatically tuned filter and its application at microwave frequencies in detail. The filter is implemented in a master-slave structure. Either the phase or the magnitude response of the master-filter at a reference frequency is used to find information on potential operating points and on the stability of the complete control structure. The theory is simulated and compared to measured results.

Design Procedure for Loss Compensation of Planar Microwave Filters Using Negative Resistances For Tuneable Bandstop and Bandpass Applications

In this paper, we present a method to synthesise microwave active bandpass and bandstop filters using negative resistance circuits and/or active inductance circuits realised in MMIC technology. We show measurements of a negative resistance circuit which is after associated with passive lumped elements to realise an active bandstop filter, tuneable in frequency. We also present the synthesis of an adjustable active inductance close to an ideal element over the 3.8-4.2 GHz band. This element is introduced in a passive bandpass filter to compensate its losses and realise a high-Q selective structure.

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)