Bernard Jarry

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.

Broadband monolithic analog phase shifter and gain circuit for frequency tunable microwave active filters

In this paper, a lossless variable gain and analog transmission type phase shifter is presented. The final function of this original monolithic circuit is to be introduced in a ring resonator planar filter to tune the frequency response and to compensate for the intrinsic losses of the resonators.

Negative resistance optimized in noise for losses compensation in microstrip resonators

A new design concept of low noise negative resistance circuit is presented considering stability conditions. Low noise properties of a negative resistance circuit are guaranteed by an optimal value of the transistor feedback. Based on this circuit, a low-noise 2/sup nd/-order 3 GHz active bandpass filter has been designed and fabricated.

Novel alternative design methods based upon combined amplification, matching and filtering approaches in MMIC technology

Two bandpass active filters using novel alternative design methods based upon combined and simultaneous amplification matching and filtering approaches have been successfully implemented. The originality of these two methods resides in their flexibility compared to the classical input and output matching lumped elements networks design method. With the first methodology based upon the combination of amplification/matching and of filtering approaches, a 5% measured relative bandwidth at 32.825 GHz has been achieved. The second approach, based upon the combination of two-step matching/filtering and of amplification is demonstrated with the design of a filter with 11% measured relative bandwidth at 14.04 GHz.

Novel detector structure for automatically tuned filters at microwave frequencies

In this paper a detector structure for an automatically tuned filter that is well-suited for application at microwave frequencies is proposed. It can be used in a master-slave structure where the response of a master filter at a reference frequency is used to derive a control signal to steer a slave filter in the signal path. The control loop is analyzed theoretically and the result is compared to a measurement.

A 2-Pole Bandpass Filter Assisted by a MMIC Impedance for Losses Compensation and Frequency Control

In this paper, we present a new 2-pole bandpass filter associated with an active impedance. The active part is equivalent to a negative resistance and a tunable capacitor. Its role is both to compensate for the losses of the filter and to adjust the resonant frequency. In a first part, we show design and measurements of the active circuit. In a second part, we associate this circuit with a passive 2-pole bandpass filter synthesised with quasi-lumped elements in microstrip technology.

Low noise and frequency tunable microwave active recursive filters using power summation principles

In this paper, a noise analysis is performed for frequency tunable active recursive filters using a noise wave formalism approach. The translation of low frequency recursive concepts is done by the use of power dividers/combiners at microwave frequencies. We then derive the characteristics of the amplifier/phase shifter employed within the filter to obtain the optimum noise factor of the structure. A MMIC chip is realized. Layout and measurements of the chip are presented.