Butterworth filter

About: Butterworth filter is a research topic. Over the lifetime, 6187 publications have been published within this topic receiving 69070 citations.

Filter unit and method for generating subband filter impulse responses

Abstract: A filter compressor (102) for generating compressed subband filter impulse responses from input subband filter impulse responses corresponding to subbands, which comprise filter impulse response values at filter taps, comprises a processor (820) for examining the filter impulse response values from at least two input subband filter input responses to find filter impulse response values having higher values and at least one filter impulse response value having a value being lower than the higher values, and a filter impulse response constructor (305) for constructing the compressed subband filter impulse responses using the filter impulse response values having the higher values, wherein the compressed subband filter impulse responses do not include filter impulse response values corresponding to filter taps of the at least one filter impulse response value having the lower value or comprise zero-valued values corresponding to filter taps of the at least one filter impulse response value having the lower value.

Minimum-Phase FIR Filter Design Using Real Cepstrum

Abstract: The real cepstrum is used to design an arbitrary length minimum-phase finite-impulse response filter from a mixed-phase prototype. There is no need to start with the odd-length equiripple linear-phase filter first. Neither the phase-unwrapping nor root-finding procedure is needed. Only two fast Fourier transforms and a recursive procedure are required to find the filter's impulse response from its real cepstrum. The resulting filter's magnitude response is exactly the same as the original one even when the filter is of very high order

A 0.55V 61dB-SNR 67dB-SFDR 7MHz 4 th -order Butterworth filter using ring-oscillator-based integrators in 90nm CMOS

Abstract: Integrators are key building blocks in many analog signal processing circuits and systems. They are typically implemented using either an opamp-RC or a G m -C architecture depending on bandwidth and linearity requirements. The performance of both these topologies depends on the operational transconductance amplifier (OTA) used to implement the integrator. Reduced supply voltage and lower transistor output impedance make it difficult to implement high-gain wide-bandwidth OTAs in a power-efficient manner. Consequently, the DC gain of the integrator is often severely limited when designed in deep-submicron CMOS processes. Conventional integrators employ multi-stage OTAs operating in weak inversion and forward body biasing to achieve large DC gain at low supply voltages [1]. These techniques require automatic biasing to guarantee robust operation under all conditions and the use of frequency compensation combined with large dimensions needed to bias the transistors in weak inversion severely limits the bandwidth and increases power dissipation. In this paper, we propose a ring-oscillator-based integrator (ROI) that seeks to overcome the limitations of conventional OTA-based integrators.

Design of a K-Band Chip Filter With Three Tunable Transmission Zeros Using a Standard 0.13- $\mu\hbox{m}$ CMOS Technology

Abstract: A novel bandpass filter (BPF), which is fabricated with a commercial CMOS process, demonstrating a low insertion loss in the passband and multiple transmission zeros in stopbands, is presented for 24-GHz automotive ultrawideband (UWB) radar systems. The filter combines a second-order asymmetrically compact resonator filter with a source-load coupling mechanism to realize three transmission zeros; two zeros are arranged in the lower stopband, and one zero is located in the upper stopband. To achieve a compact layout size and a low insertion loss, a semilumped approach, which is accomplished with mixed utilization of high-impedance coplanar waveguide lines and lumped capacitors, is used to construct the chip filter. A K-band experimental prototype that has a very compact size of 0.35 × 0.8 mm2 was realized. The average insertion loss in the filter's passband is about 2.7 dB, the return loss is greater than 15 dB within the frequencies of 24-27.5 GHz, and the attenuation levels at the three transmission zeros all greater than 35 dB.

A Dual-Band Bandpass Filter With Widely Separated Passbands

Abstract: A novel and compact design of a dual-band filter with widely separated passbands is proposed. Applications of such a device can be found in systems where a single device is responsible for both transmission and reception. The proposed filter is composed of resonators working on two distinct modes. The proposed dual-mode structure offers a good rejection of unwanted resonances, producing a widely separated dual-band response. The idea is demonstrated with the design of a four-pole filter comprising two dual-mode structures and the concept is verified experimentally by the measurement of a fabricated prototype. Finally, a six-pole filter is proposed, showing the possibility of designing higher order filters.