Electronic filter

About: Electronic filter is a research topic. Over the lifetime, 13207 publications have been published within this topic receiving 93063 citations. The topic is also known as: filter.

A universal low-Q active-filter building block suitable for hybrid-integrated circuit implementation

Abstract: A highly versatile second-order active-filter building block for low- Q applications (Q is described. The versatility is obtained by combining features inherent in the Sallen-Key circuit topology and those pertaining to hybrid-integrated circuits (HIC's). A high degree of circuit stability is obtained by designing individual network functions to depend primarily on the characteristics of stable thin-film resistors and capacitors. Frequency- and Q -sensitivity are examined in detail. Methods of minimizing Q -variation with respect to the active and passive elements are discussed. Lower bounds on the Q-variation obtainable with the hybrid-integrated filter building blocks are given. All possible second-order network functions, including the allpass function, can be obtained with the building block. The resulting universality and standardization permit the complete design of active filters consisting of cascaded building blocks by computer.

Composite filter chip

Abstract: A composite filter chip includes a stacked chip made by stacking a first chip and a second chip. The first chip has a first filter circuit formed on the main surface thereof. The second chip has a second filter circuit formed on the main surface thereof.

Surface acoustic wave filter

Abstract: The present invention disclosed a SAW filter in which unnecessary space on a chip (11) can be reduced in comparison with the prior art, and in which a smaller chip can be realized. Because oblique step shaped reflection surfaces (14, 15, 54, 55, 64, 65) are provided in- order to reflect the SAW, a smaller SAW filter than that used in the prior art can be realized (Figure 1).

Modular log-domain filters realized using wave port terminators

Abstract: Log-domain wave filters that simulate the passive LC ladder prototype filters are introduced in this paper. The proposed circuits are constructed from the wave equivalents of the reactive elements corresponding to those in the prototype circuit. The wave equivalent circuits are obtained by using a novel log-domain wave port terminator. The wave equivalent of a capacitor in a shunt branch was chosen as an elementary building block for creating high-order filters. The wave equivalent circuits of all other reactive elements in a shunt or in a series-branch connection can be readily obtained using the elementary building block plus some inverters. This way the derived high-order filter configurations are modular. A design example of a third-order elliptic low-pass filter is given, and the performance of the filter was verified by simulation.

A Digital Interpretation of Frequency-Periodic Signal-Interference Microwave Passive Filters

Abstract: This paper addresses, for the first time, the digital representation of spectrally periodic signal-interference microwave passive filters. Starting from the theoretical rational transfer function of a synthesized transmission-line signal-interference analog filter, the real-valued coefficients of its digital-domain filter counterpart are derived. This discrete-time formulation for this type of microwave filters allows to clarify some confusing concepts into them, such as filter order. Moreover, some particular phenomena observed in associated experimental proof-of-concept planar prototypes, such as the appearance of out-of-band/spurious resonance peaks, are also explained by this study as zero-pole quasi-cancellations. In addition, it is demonstrated here that the use of the adjective “transversal” for this class of microwave passive filters could be no rigorous as it is understood in a digital sense since its discrete-time modeling commonly obeys an infinite-impulse-response structure. For validation, the expounded theoretical framework is applied to three examples of signal-interference passive filters exhibiting quasi-elliptic-type single-passband, six-passband, and low-pass responses.