### 抄録

It is often desired to change the cutoff frequencies of digital filters in some applications like digital electronic instruments. This paper proposes a design of variable lowpass digital filters with wider ranges of cutoff frequencies than conventional designs. Wave digital filters are used for the prototypes of variable filters. The proposed design is based on the frequency scaling in the s-domain, while the conventional ones are based on the z-domain lowpass-to-lowpass transformations. The first-order approximation by the Taylor series expansion is used to make multiplier coefficients in a wave digital filters obtained from a frequency-scaled LC filter become linear functions of the scaling parameter, which is similar to the conventional design. Furthermore this paper discusses the reduction of the approximation error. The curvature is introduced as the figure of the quality of the first-order approximation. The use of the second-order approximation to large-curvature multiplier coefficients instead of the first-order one is proposed.

元の言語 | English |
---|---|

ページ（範囲） | 263-271 |

ページ数 | 9 |

ジャーナル | IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences |

巻 | E77-A |

発行部数 | 1 |

出版物ステータス | Published - 1994 1 |

### Fingerprint

### ASJC Scopus subject areas

- Hardware and Architecture
- Information Systems
- Electrical and Electronic Engineering

### これを引用

*IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences*,

*E77-A*(1), 263-271.

**Synthesis of variable wave digital filters.** / Watanabe, Eiji; Ito, Masato; Murakoshi, Nobuo; Nishihara, Akinori.

研究成果: Article

*IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences*, 巻. E77-A, 番号 1, pp. 263-271.

}

TY - JOUR

T1 - Synthesis of variable wave digital filters

AU - Watanabe, Eiji

AU - Ito, Masato

AU - Murakoshi, Nobuo

AU - Nishihara, Akinori

PY - 1994/1

Y1 - 1994/1

N2 - It is often desired to change the cutoff frequencies of digital filters in some applications like digital electronic instruments. This paper proposes a design of variable lowpass digital filters with wider ranges of cutoff frequencies than conventional designs. Wave digital filters are used for the prototypes of variable filters. The proposed design is based on the frequency scaling in the s-domain, while the conventional ones are based on the z-domain lowpass-to-lowpass transformations. The first-order approximation by the Taylor series expansion is used to make multiplier coefficients in a wave digital filters obtained from a frequency-scaled LC filter become linear functions of the scaling parameter, which is similar to the conventional design. Furthermore this paper discusses the reduction of the approximation error. The curvature is introduced as the figure of the quality of the first-order approximation. The use of the second-order approximation to large-curvature multiplier coefficients instead of the first-order one is proposed.

AB - It is often desired to change the cutoff frequencies of digital filters in some applications like digital electronic instruments. This paper proposes a design of variable lowpass digital filters with wider ranges of cutoff frequencies than conventional designs. Wave digital filters are used for the prototypes of variable filters. The proposed design is based on the frequency scaling in the s-domain, while the conventional ones are based on the z-domain lowpass-to-lowpass transformations. The first-order approximation by the Taylor series expansion is used to make multiplier coefficients in a wave digital filters obtained from a frequency-scaled LC filter become linear functions of the scaling parameter, which is similar to the conventional design. Furthermore this paper discusses the reduction of the approximation error. The curvature is introduced as the figure of the quality of the first-order approximation. The use of the second-order approximation to large-curvature multiplier coefficients instead of the first-order one is proposed.

UR - http://www.scopus.com/inward/record.url?scp=0028274328&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028274328&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0028274328

VL - E77-A

SP - 263

EP - 271

JO - IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences

JF - IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences

SN - 0916-8508

IS - 1

ER -